CA1088845A - Surge suppression - Google Patents

Abstract

SURGE SUPPRESSION
ABSTRACT OF THE DISCLOSURE
A surge suppression system for dampening surge pressures or pipe hammer by introducing a gas into a flow conduit in such an amount that the introduced gas is in excess of that required to saturate the liquid. Preferably, the gases are those which are relatively inert or not unduly reactive and which posses relatively low saturation levels with respect to the liquid. Desirably, the gas is added through a member to the flow conduit in a vicinity of high tubulence. The surge suppression system can be utilized in generally any liquid system and particularly in a liquid transmission system.

Another embodiment pertains to a scrubber or washer for generally purifying gases and may contain one or two stages to efficient-ly remove impurities as through the use of high solubility fluids, fluids which decompose contaminants or which contain or provide (i.e heating stage) catalysts to decompose contaminants, oxidizing agents, or re-ducing agents. The scrubber contains a packed bed and the packing may be characterized as one where the inside hydraulic radius equals the hydraulic radius of the external flow channels. The washer or scrubber type apparatus is particularly suitable for treating (purifying) materials such as ozone utilized in a deodorizing or disinfecting system.

Description

Another embodiment pertain~ to the purification of a gas by treatment with a fluid in a flow conduit having a plug flow at itB
entrance containing an injection-mixing device coacting with a first high turbulence cau~ing device and a down~tream or Yecond high tur-S bulence causing device. The treatin~ fluid i~ preferably added to the vena contracta of the first high turbulence causing device.
The present invention also relates to a two stage oxidative system for the disinfection of material containing nitrogen commonly in the form of ammonia or ammonium a~ in the treatment of waste or sewage plant effluent by adding a primary oxidizing agent to the effluent and by adding a ~qecondary oxidi~ing agent to produce a ~ynergistic disinfection system in which the distribution of ammonium and ammonia is shifted to nearly all ammonium. A desirable pH level is 7 or le~s with desirable primary oxidizing agents including alluminum chloride or ferric chloride with desirable secondary oxidizing agents including chlorine, chlorine dioxide, ozone a~ in oxygen or air, or sodium hypo-chlorite .
Another aspect of the present invention relates to the nitrifi-~
cation of ammonia in the form of secondary treatment effluent from a waste treatment system wherein the ammonia is converted to nitrates so that the effluent ha~ low ammonia content.
A rotary distributor arrn comprising Improved distribution noz~les and a flow control acconlplished by a gradual taper to the arm itself is defined which insures a urliform distribution across the ~ul} radius of the distributing medium so that uniformity and :' ;: ' s optimum economy and efficiency are achieved with respect to the trickling filter itself because uniform fluid is distribut~d across the entire top surface thereofO
The invention further operates an injection mixing system in a contact tznk utilizing efficient mixing devices for disinfection and a unique flowthroùgh arrangement into an influent trough as well as the contact ~ank whereby maxLmu~
dispersion of the disinfectant throughout the influent with maximwm economy is achievedO
CROSS REFERENCE
This application is a divisional application o~ my co-pending Canadian Patent Application Serial NoO 237,396 System for Pollution Suppression~ filed October 7, 19750 ~ _ .
The present invention relates to a surge suppression system for preventing surge p~essures or pipe hammer in liquid ~ystemsO More 3pecifically, the present invention relates to the suppression of surge pressures or:pipe hammer in liquid pumping proeessesO
Heretofore, various techniques have been utilized to recluce sur~e pL'C'';'iU.~'CS (~ e h.l~r~er ill liquid sys-tel~s wherc commonly a pump is cmployed. However, most of the~e techni-ques tend .o b~ sophistic~ted, unec:onomic~l, or irnpractical and furt;lexmore do not grea-tly r~duce the surge pressure in the system. One technique utili~ed a fly wheel to increase the inertia of the pump motor. Another technique was based upon the use of a stand pipe which may be either of a standard or the differential type. The latter type is more common as a means for protecting against under pressures which occur incident to flot~ regulation in penstocks of hydraulic turbines.
Another technique requires the provision of a storage tank or air vessel. A variation of this technique is a so-called one way storage tank, that is a storage tank equippecl with a check valve which only permits flow during line under pressure or :
the like. A further variation of the storage tank technique is the utilization of a very large storage tank which may be a reservoir of water Gpen to the earth's atmosphere.
The present invention also relates to the use of a ``~
scrubber for the general purification of a gas compound wherein ' the hydraulic radius of cylindrical media contained in the scrubber is equal to the hydraulic radius of the e~ternal flow ~ '~
channel. More specifically the present invention relates to a scrubber or washer wherein one or two stages may be utilized to thoroughly purify a gaseous compound through the use of high solubility fluids, oxidiziny agents, or reducing agents.
Heretofore, scrubbers containing packed beds and the '' ; ' ' like ha~e been utiIized to effect fluid phase absorption. ;'~
Al'hough~tha removal of an undesirable compound is effected, ' generally the efflciency of the process is degraded by ~4~
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restrictions on hydraulic loading, compromises bet~een gas and liquid f~o;~ or excessive gas-phase system pressure drop. With respect to purification, fluids have been utilized which are not highly soluble. Moreover, solids such as activated carbon have been used and thus require periodical replenishment.
The present invention relates to the treatment or purification of a first fluid with a second fluid possibly a gas, with the first fluid under turbulent flow conditions in a flow Fonduit. More specifically, the present invention relates to the purification o~ a firs~ fluid by a fluid (gas) in a flow conduit wherein turbulent flow exists to achieve thorough mixing or momentum transfer.
Heretofore, fluid phase treatment systems have been utilized in purifying fluids such as liquid of gases. In the purification of a gas by other gases, purification has largely ;~
- been confined to contact chambers, packed beds and the like.
In such systems the treated fluid circulates through the cham- ;
bers. The treating fluid achieves contact with the treated fluid in the packed bed. Where the active agent for treatment is a gas, it is dissolved in the treating liquid. Contact is achieved as before. However, direct contact is possible between a treating gas and a treated fluld. Although some purification is obtained, the amount is les. than desirable, ., '~'.',' ..

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s The present invention relatcs to a synergistic two stage oxi~ative sys-tem for dlsinfection oE mat~rials. More speci~ically, it relates to a synexgistic two stage disinfec-tion system utilizing a primary oxidizing agent in one stage an~ a secondary oxidizing agent in a second stage for the treatment of waste or sewage effluent.
- Heretofore, in ~he field of disinfection, and prima-rily with respect to the treatment of waste or sewage effluentr oxidizing agents have been used- to disinfect the effluent.
However, use of the various oxidizing agents even in combina~
tion mainly gave a reduction in bacteria proportional to the amount used or to the amount of multiple compounds utilized.
Moreover, the treated efEluent was usually very high in ammonia which itself exer-ted a high demand for secondary oxidizing agent or which required extensive further treatment to remove it from the system and prevent it from being discharged into streams or waterways where it possessed a highly toxic effect upon fish and marine life. Additionally, large scale xemoval of the a.~monia by venting to the earth's atmosphere was often ` ~;
undesirable due to odors and pollution problems.
The invention relates to a system for the production of effluent from a waste treatment process containing low am-monia. More particularly, the invention relates to a system, às above, wherein the secondary treatment effluent is admitted - ~
to a nitrification tower through a special distributor, aerated -~
according to a special process, filtered through media having a special hydraulic parameters and wherein the nitrification `~
tower is insulated.

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lleretofor~, various methods and procedures have been utilized to convert ammonia to ammonium nitrogen in waste or sewage treatment plants. ~lthough some of the various pro-cedures have produced effluents with low ammonia, the processes are generally ccmplex and costly, and do not operate consistently year-round.

SUMMARY OF THE INVENTION
It is therefore, an object of the present invention to provide a surge suppression system wherein a gas is injected -~into a liquid at some point along a liquid flow system in an amount in excess of the gas saturation level of the liquid.
It is a further object of the present invention to provide a surge suppression system, as above, wherein the in~ection of the gas is at a high turbulence portion of flow of the liquid flow system. ~
It is a further object of the present invention to ;
provide a surge suppression system, as a~ove, wherein high turbulence causing devices are loca~ed within the liquid flow system coincident with the gas injecting points.
It is an additional object of the present invention to provide a surge suppression system, as above, wherein additional turbulence causing devices are located downstream from the gas injection-turbulence causing devices.
It is still another object of the prese~t invention to pro~ide a surge suppression system, as above,whichis parti~
; Gularly suitable for utilization in liquid transmission systems.

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'' "~''"' "' ~' ~ ccordillg to the present invention, a surge ~uppression system for dampening surge pressures is character-ized by a force main carrying a liquid, a ~lat plate orifice, said flat plate orifice causing a downstream vena contracta portion i~ said liquid, said flat plate orifice located in said main, the diameter of said orifice ranging from about 0.7 to about 0.9 of the diameter of said main, an injector means for : .
introducing an amount of a gas into said main, said injection means having a small pipe, said pipe having a tip, said gas 10 flowing through said pipe tip, said pipe tip located in said .:
vena contracta portion so that said gas is dispersed into said liquid, said small pipe tip being located at about 0.25 to about 0.5 main diameters downstream from said flat plate orifice, said vena contracta portîon located in the central portion o~ ~
said main, and the amount of said introduced gas being in excess i~ ~`
of that required to saturate said li.quid so as to dampen surge ;~
pressures. .
It is therefore, an object of the present invention :
to provide a scrubber for the purification of a gas through the use of fluids having preferential and high solubility, possibly causing decomposition or containing catalysts to promote ~.
decomposition, or being heated to cause decomposition oxidizing agents or reducing agents. :~
It is another object of the present invention to ;`
provide a scrubber for the purification of a gas ~herein the scrubber contains conventional or specialized packing media and the hydraulic radius of the external flow channel may be equal to the hydraulic radius of the internal flow channel. `.
It is a further object of the invention to provide a : 30 scrubber for purifying a gas wherein the scrubber has one or two stages.

It is an additional object of the present invention ~ '~.

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x to provide a scrubber for the purification of a gas, as above, wherein the particular gas is ozone.

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~4~, : --Generally, the pre~ent invention relates to a process for the purification of a ga~, compriaing, adding the ga~ to an injecting mixing rontacting region, a scrubber containing a packed bed, adding a fluid to the scrubber selected from the class con~i~ting of qolubility ags:nt~, 5 oxidizing agents and reducing agents, conveying said ga~ through ~aid packed bed and exhau~ting ~aid treated ga~.
It i6 therefore an object of the preqent invention to provide a fluid phase treatment sy~tem having a turbulence cau6ing device to maJci-mum contact.
It is a further object of the present invention to provide a fluid pha~e treatment ~y~tem, a~ above, having a downqtream turbulence cau~ing device.
It i~ a basic objective of the present invention to provide a fluid ;
treatment sy~tem with a treating ~as-phase fluid wherein injection-mixing 15 and contact operations are operated under precisely controlled conditions of flow to maximize contact opportunity and to minimize the nece~qary concentration of treating fluid (ga6 ~ required. The key to achieving these ~conditions i~ seen to be: to inject and mix 90 as to suppress the concentra-tion gradients in the axial and in the angular direction~ at a point where 20 inten~e radial mixing i8 induced by a turbulence-causing device and with a high concentration gradient in the radial direction owing to the coa~ial in-jection of treating~fluid (gaq) into the treated fluid ~liquid or gas) , ~
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reco~nizing that this r~d.ial concentration gradient will be attenuated downstream of the injection po.int within a transi-tion length, the distance required to establish a stable velo-city profile in turbulent flow, 25 to 50 diameters, and pre-ferably at least 50 diameters, then to ensure suppression of any residual radial concentration gradient at the end of the transition length, a second turbulence causing device is introduced. ~his induces intense radial mixing, so suppressing . any remaining radial concentration gradient. Where said second turbulence-causing device is a flat plate ori~ice, a - further feature comes into play. That is, the flat plate orifice is one of few, if not the only turbulence-causing devices which completely removes the laminar and turbulent :.
boundary layer from the conduit wall mixing it into the main stream of treated fluid flow. From this device conta~ at :
maximum probability of contact between treating fluid and treated fluid may con$inue for a period dictated by reaction ..
rates. Owing to suppression o~ concentration gradients and to the intense mixing, the reaction rate will be maximized minimizing the contact time and the concentration required ~ :.
for the treating fluid (gas). . :
Generally, the invention relates to a process for the .
treatment of a fluid by a treating fluid comprising, adding the fluid to a flow conduit such that the Reynolds mem~er is at least 3,000, said flow conduit having a turbulence-causing .

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- , . -device, adding a treating fluid to said 1uid channel and exhausting a treated fluid.
It is therefore, an object of the present invention to provide a ;~ two stage oxidative system for the disinfection of material containing a distribution of ammonia and ammonium wherein a primary and a secondary oxidizing agent are utilized.
It ij another object of the present invention ~o provide a two stage oxidative system for disinfection, as above, wherein the pH level of the material is lowe.red.
It i3 a further object of the present imrention to provide a ; two stage oxidative system for disinfection, as above, wherein syner-gistic di~infection results are obtained. ~ ~
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It is an additional object of the present invention to provide a `1 two stage oxidative system for disinfection, a6 above, for the treatment , ?,~ 15 of potable or treatment water, wa~te or sewage efiluent, ~, lt is stlll another object of the present invention to provide a two stage oxidative system foI disinfection, as above, wherein the primary oxidizing agent is utilized in the first stage and the secondary oxidizing agent is utilized in the second stage.
It lS a still further object of the present Invention to provide a two seage oxidative system for disinfection, as above, in which the ~;
dis~ribution of compounds ~f ammonia and amrnonium i~ shifted to sub-stantially ammonium.

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s The invention relate~ to a two ~tage oxidative proces~ for disinfection of material containing a distribution of ammonia-ammonium compounds, comprising, adding a pr~nary oxidizing agent to the material and adding a secondary oxidizing agent to obtain a very low bacteria count where the ammonia-arnmonium distribution is shifted toward ammonium.
It is therefore yet anot er object of the invention to provide a sy~tem wherein ammonia in the secondary treatment effluent of a waste treatrnent plant is readily oxidi~ed to stable nitrates.
It is yet another object of this invention to produce an effluent in a waste treatment plant having low ammonia content through the utilization of a distributor, an aeration apparatus and a packing bed having specific hydraulic parameters.
In general, the present invention pertains to a waste treatment ~ystemfor low ammoniai effluent compri ing a nitrification tower, sai~
nitrification tower containing a packed bed, feeding secondary treatment `~ `` ef1uent to; said nitrification tower, said secondary treatment effluent ` ~ aerated to contain dissolved oxygen, said oxygen added to said effluent through a small tube in a tubulent causing device.
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For a better understanding of the invention reer-ence should be had to the accompanying drawings wherein: -Fig. 1 is a block diagram, schematic illustration of the newly proposed system.i~..~ota~ showing flow arrangements and the stages involved;
Fig. 2 is a plan view of an improved settling tank comprising one of the stages in the system;
Fig. 3 is a cross-sectional view of the settling tank of Fig. 2 taken on line 3-3 thereof; -Fig~ 4 is a cross-sectional, schematic view of aD
improved trickling filt ~ ~Q~p~s~g a stage of the system of :
the invention; .
Fig. 5 is a schematic flow diagram of the disinfec tant unit indicating the operation under a hydrauiic gradient ~ ;
with sensors and gas input control;
Fig. 6 is an enlarged cross-sectional:view o~ one `~
of the flat plate orifices associated with th~ disinfection , unlt of Fig. 5 indicating the gas input and sting relationship to the orifice to obtain-maximum efficiency in the introduc~
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tion of the disinfecting gas,.and the elimination of concentra- , tion gradients; .-. . `~ :
Fig. 7 is a flow diagram of a modified basic~system illustrating system optimization and flow control; . - ~;.
Fig. 8 is a graphic illustration of the assumed in~
fluent hydraulic and organic load;

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Fig. 17A is a cross-sectional view of a highly efficient ~luid-~luid treatm~nt system u~ilizing high turbulence~causing devices. ;
~ig. 17B is a schematic view showing a grid located in a portion of the fluid-fluid treatment system.
Fig. 18 is a graph setting forth the relationship between temperatures, pH and the equilibrium between ammonium and ammonia.
Fig. 19 is a cross-sectional view of a nozzle.
Fig. 20 is a plan view of a large diameter distri-bution arm and its rotating support post; -~
Fig. 21 is a front elevational view of the distri-bution arm of Fig~ 20;
Fig. 22 is a plan view of the arm alone indicating ~
some of the internal structure in dotted lines; ~`
Fig. 23 is an elevational view of the arm o Fig. 22;
Fig. 24 is a broken away enlarged view of the nozzle arrangement taken from the circled area of Fig. 23;
- Fis. 25 is an enlarged cross-sectional view taken on line 25-25 of Fig. 22; , Fig. 26 is a modified double flow channel similar to that shown in croSs-sectional configuration of Fig. 25;
Fig.~27 is an enlarged cross-sectional view to show ; the flow path in the distribution head to define the double ~; ~ flow channel of Fi~. 26;
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- , , , ' , ' Fig. 28 is an enlarged elevational view of the dif-fusing nozzle utilizcd in the distributor arm of Flys. 20 -~3;
Fig. 2g is a side elevational view of an alternative -~
sweep elbow that might replace the dif fusing nozzle of Fig~ 28;
Fig. 29A is an end elevation of the sweep elbow of Fig. 29 indicating a flattened end outboard;
Fig~ 30 is a graph illustrating optimum concentra-tions of polyelectrolyte feed for maximum removal of suspended m~tter;
Fig. 31 is a plan view of a contact tank incorpora-ting the preferred injection mixing system of the in~ention;
Fig. 32 is a cross-sectional view of the tank of Fig.
31 shortened in length, taken on line 32-32 of Fig. 31;
- Fig. 33 is a partial cross-sectional view of the - ~
contact tank taken on line 33-33 o Fig. 31; ~ ~ ~
Fig. 34 is an enlarged broken away view o the injec- -tion mixing elbow utilized in the tank of Fig. 31; and Fig. 35 is a schematic illustration of an activated 20 sludge air injection system for an activated sludge system. ~-Fig. 36 is a graph illustrating energy requirements ; ~ ;
for ozonation only; and Fig. 37 is a schematic illustration of a ~ypical system for the production of ozone.

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s DEFINITION OF TERMS PSEUl~OMONAS, ~LCALIGENES, FLA~IOBACTl~RIUM, MICROC;OCCUS AND ENTEROBACTERIACEAE
ACTIVATED SLUDGE
All type~ of bacteria make up activated sludge, however, in 5 usual operation obligate anaerobes will attenuate in nurnber in re~pon~e to the presence of air. A proteinaceous waste will favor alcaligenes, flavo bacterium and bacillus. A carbohydrate waste will proliferate pseudomo-nas as well.
ANAEROBIC DIGESTERS
The anerobic digester bacteria include facultative and obligate anaerobe~ in active metaboli~m. Dormant aerobic orms may be pre~ent, such as spores of fungi. Acid formers are predominantly facul-tative forms although a few obligate anaerobes have metabolic end products which are acld.
lS Me~hane former~ are obligate anaerobes, methanobacterium, i methanosarcina and methanococcu~ in the metabolic pathway to subse-, quent end product~ where methane is a precursor, the pathway can be .~ ~
' intersected owing~. to the implied vulnerabillty of methane formers to oxygen, oxygen-ozone OT air. Thus, selective disinfection provides a ;, 20 means to inhibit methane formation or to deny a metabolic pathway to , succeeding end products where methane is the necessary precur~or. With j~ denial of a pathway, an alternative pathway may be stimulated by changing .i :
environmental conditions such as an aerobic activity. In this way, methane would not be formed. The source material, carbon dioxide would not be Z5 reduced. Thl~ is an unneces~ary step in waste treatment, since carbon dio~ide i~ a stable end product of aerobic treatment. The hydrogen i .

.~ ., , s involved ~uld not be acted upon. lt i~ probably a con~tituent of formic or acetic acid. Thus, the alternative metabolic pathway opened is that for aerobic microbiological decompo~ition of acetic acid. Instead of the anaerobic sequence acetic acid, acetoacetic acid to acetone acid isopro-5 panol or to butyric acid and butanol, this invention develop~ the aerobicsequence. It i8: acetic acid, possible pyruvic acid, oxalacetate, citrate and the citric acid (Krebs) cycle to terminal oxidation.
In a similar way, the anaerobic reduction of sulfates by the obligate anaerobic, desulfovibrio can be inhibitecl. Shifting to an aerobic 10 environment denies a pathway to hydrogen sulfide. It ha~ been found that this is readily achieved practically by aeration. C;onsequences include a marked reduction in objectionable odor and long per~i~tence of aerobic action. The latter caRe is demonstrable by unexpectedly deferred methy-lene blue stability tests indicating a shift to products of anaerobic meta-15 bo11sm, MICROORGANISMS IN WASTE TREATMENT
Trickling Filter. Filter microorgani~ms refiect the faculta-.tive nature of the filter. Predominant are bacteria; aerobic, faculta-tive and anaerobic. Obligate aerobic spore formers bacillus are easily 20 found in the upper, aerobic plaques. The obligate anaerobe, desulfovi-brio can be found in lower levels at the plaque-stone interface where, in usua1 practice, DO i8 zero. The majority of bacteria are facultatlve, living aerobically ontil DO zero~, then anaerobically.
With reference to the drawings, Fig. 1 illustrate~ the ~ste 25 treatment equipment, process and overall system of unit operations in which the invention operates . A primary sedimentation tank i8 indicated by numeral 10. The tank 10 receives comminuted raw waste including settleable ~olids from a line lZ is~uing from a main line 14. A multi-plicity of such lines 12 and E)ubsequent operations may exist.
Two other flows are introduced froln the operations which follow, 5 constituting feedback of digester ~upernatant line 12a and of primary recirculation line 12b. The supernatant fraction is waste having high organic loading, relatively low flow, and it is resistant to aerobic pro-cessing for two reasons. First, it presents a biotal population adapted to anaerobic dige~tion and second, its organic compo~ition includes the pro~
10 ducts of anaerobic metabolism.
The second fraction of flow is the primary recirculation usually -~ .
occurring at rate~ in the range of one half to three times the raw ~ ~:
waste rate. The recirculation flow is characterised by~low organic loading and a high degree of treatability in an aerobic process.~ It exerts dilution 15 effects on the raw waste which are not only marked, but which may be used in conjunction with secondary recirculation to~ great advantage in smoothing .
hydraulic and organic loading, as dlscussed later~

These three flows are impressed upon primary sedimentation.
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Regulatory authorities often stipulate hydraulic design criteria for sedi~
20 mentation equipment in terms of the tank overflow rate which prevails for the composite flow. Such overflow rates may`be affected by the technique illuatrated in Flg. l of intercepting a portion of flow to be fed forward : ~ ~
to bioprocessing indicated by numeral 16. As discussed later, in Fettling, u~ing feed forward techniquea, additional benef~ta accrue for example in 2S organic load amoothing.

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The basic flow irom primary seclimenta~on 10 procecd~ to a primary stage of bioprocessing 16. A roughing trickling filter is illus-trative. There, to the sediInented ba~ic flow, three component flows may be added. One 18 icl the feed forward intercept flow noted previou~ly. The 5 second 20 is the bypas~ing fraction of primary recirculation. The third 22 is the secondary recirculation shown in Fig. 1. The existence of the feed-back flows, the feedforward flow and the basic influent flow prior to bio-proces~ing is important. This combination provides sufficient degrees of freedom to enable independent regulation in thi~ and succeeding operations 10 of hydraulic and organic loading with siome flexibility and without over-loading primary ~edimentation. From the bioprocessing operation 16, such as the roughing filter shown, in most case~ j existing plant flow proceeds to secondary sedimentation 24. In some inijtances, a second stage of bio-proce3sing 26 may be present. Usually this would be a firlishing trickling 15 filter. Rarely, but preferably, it would be an activated ~ludge ~tage of bioprocessing.
In thi~ instance, as ~hown in Fig. 1, from the first stage of bioprocessing 16, the flow is split, with primary recirculation over line 12b withdrawing a iraction for feedback to an earlier stage of proces~ing 20 10. The remaining fraction proceeds to the second stage of bioproces~ing 26. Before introduction to bioprocessing 26, 6uch as to the activated ~ :
s1udge operation, it may be mixed with recirculating activated 8 ludge from 1ine 28.
A remaining portion of the recirculating activated sludge, is 25 discharged for d;gestion with the primary sedimentation tank sludge in a primary digester 30 and secondary digester 32.

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From th~ activated sludge operation 26, the flow proc~ed~ to secondary sedimentation 24. The regulatory authorities stipulation on overflow rate again prevails; houever, the permissible overflow rate for secondariea 24 rnay differ for tho~e from prirnaries and rnay further depend S upon the type o bioprocessing operation involved. The activated sludge operation i9 characterized by highrates of recirculation over line 22 of sedimented sllldge as suggested in Fig. 1.
From the secondary sedimentation operation 24, flow may be intercepted for feedback recirculation over line 22 after partial sedi-lO mentation. A second fraction of fully sedimented flow may be returned in the basic secondary recirculation by line 34. The remaining fully sedi-mented flow proceeds to disinfection over line 36. In the disinfection unit 38 operation, in-line gas-liquid disinfection over line 40~by injection may procede the conventional contact chamber disinfection. The techni-15 ~ que of gas injection is more fully defined hereinafter. The same, or ..
complementary disinfectants may be used. For example, in-line ozona-~; tion might be followed by contact chamber chlorination in unit 38. ;
~Alternatively, chlorination may occur In both stages or only m the contact : ;
chamber with no in-line dismfection. Disinfection yields the final Z0 effluent over line 42.
It has been shown in Fig. 1 that sludge is removed from waste at successive stages of waste treatment. The sludge is stabilized, u~ually in two-stage anaerobic digesters 30 and 32, From the digester 32j sta-.

bilized sludge may be discharged to drying on beds, in a kiln, fluidized 25 bed~reactor or on a vacuum dewatering drum. Ultimate disposition of : .
solids products may be land fill or incineration. Di position of digester ~; :
supernatant over line 12a has been noted previously. It is thi~ overall ~,. .
, framework of unit operations within ~ich the concepts proposed by the invention must be implemented. Di~cussion will now proceed in terms of each of the unit operations de~cribed. A final ~ection will deal with optimurn systems integration.
It should be noted however that aeration or other injections may take place at a considerabls number of other points into the effluent in the syst~m of Fig. 1. Specifically air may be injected into the digester supernatant recirculation, the raw waste input, the effluent from disinfection tank 38 and to the effluent from the sf~condary bio- ~ ;
processing tank 26. In some in~tances it is de~irable to i~ject a chlorine water solution into the effluent before disinfection to obtain point chlorina-tion. It should further be understood, of course, that chlorination may be used in the disinfection tank 38.
SETTLING ~`~
Settling or sedlmentation is a standard unit operation in waste ' ~ treatment. The effectiveness of this operation is essential because of th~
high concentration and broad size range of the particles present in sewage.
The concentration of these particles falls in a size classification from a diameter of 0. 000001 to 5. 0 millimeters. This is an important character- ~ ;~
iatic, since it affects the settling velocities ~pon which sedimentation or clarification depend. The significant velocities range upwards from a lower limit of 10 9 millimeters per second. These velocities are achieved in clarificahon or settling in sewage treatment and are of primary interest owing to their broad range and extremely low magnitude.
The importance of this from a practical standpoint is in the degree of momentum exchange, vorticit~r, or of turbulence which will .

., .. .. .. .. . . , ;. .. .. ;.. ,, . ~, 4~i degrade settling or clarification processes. Obviously, it iB any level of velocity which approaches the settling velocities described. The sig-nificant implication of this, of course, i~ in the fact that the kinetic energy which is present at the influent to the sedimentation charnber should be reduced to the lowest possible practical level. Anything which tend~ to increase the kinetic energy of the influent jet will degrade the performance of the clarification or sedimentation process. Recircu-lation has such effects, however, i~ has off~etting compen~atory ad-vantages in diluting the organic load to be handled. In contrast, high velocity, Or excessive momentum exchange impose a penalty without an offsetting advantage.
For an understanding of the basic construction of the settling tanks 10 and Z4, reference should be had to Figs. 2 and 3 of the drawings.
The specific effects of the modificat;on3 of the settling chamber are a~
1 5 follows:
a) To control the fluid path prior to free settling.
b) To reduce the velocity and turbulence level at the influent to the region o free settling.
c) To increase the settling flow path length and the time available for settling. ~;
d) To increase the functional effectiveness of ; settling.
e) To reduce, by forward-feed techniques, the hydraulic load on the settling tank and particularly to reduce its overflow rate.
f) To introduce a further degree of freedom in hydraulic -and organic load existing in present feedback recir-c ulation .

.

~O~ 5 The apparatus making up the improved Yettling tank of the invention may be fitted in a conventional circular settling tank. It~
di~tinqui~hing element ia a rotationally-transformed radial or hyper boloidal-envelope difuser. The diffu~er may incorporate spiral vanes indicated generally by numeral 60a. The rotational transformation is through 7 or less to ensure minimum probability of flow separation at the channel boundary. This is a critical factor in the three-dimen~ional diffuser design owing to the flow deceleration which is induced.
Smaller, bu1t ~imilar, three-dir~ensional spiral-shaped collectors 62 and 64 may be u~ed at one or more centrally located annular collection points to provide upper effluent collection and/or intermediate effluent collection, respectively. There, flow is accelerating and boundary layer separation is much le~s significant.
In a conventional sedimentation tank, influent and effluent flow may be distinquished. Previously and in existing art, these have not been considered in terms of optimum overall circulation. The case~ is illus-trated by the conventional circular plan view s~dimentation tank. In it, flow is usually upward in a central influent well. At the upper limit of this central well, flow is predo~ninantly radially outward with both rela-tively high turbulence and velocity.
In such a tank, the predominantly radially directed surface jet induces a circulation in the central region. In consequence, a 8US-tained toroidal vortex circulation developY there. This means that the ~ ~ 1ntended settling flow is perturbed. It is degraded functionally by rota-;~ 25 tional mixing usually imposed mechanically and gravitationally by earth rotation. The result is settling circulation.
,~ , .

Concurrently, the outflow is predominantly a peripheral, radial flow. It induces a similar toroidal vortex at the overflow weir.
This toroid exhibits comparably lower velocities, lower turbulence and a much larger diameter. 'rhis circulation i8 of lower energy level corres-5 ponding to the reduced overflow velocity. The direction, or sense ofrotation, in the second toroidal vortex iB the ~ame as in thc influent circulation. This means that at an intermediate radial position in the tank, the two toroidal vortice~ interact with opposing local vertical components of flow. This interaction manifests itself by momentum exchange which ;~ 10 degrades settling.
~ ! :
To attempt sedimentation under imposed condition~ antagoni~tic to the functlonal objective seems ill advised. A de~irable si~uation is to recognize that an overall circulation must be considered and that the direct and induced flow described must be complentary t~ the necessary 15 clrculation. This iA the general objective of the settling tank of the inven-tion.

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This iB po3~ible under the caae for circular plan view sedimen-tation if a single toroidal vorte~c may be induced under controlled condi-tions of overall circulation. Preferably, this should be done in such a way as to enh~Lnce the primary sedimentation flow and, if necessary, to 5 yield a secondary effluent having predictable sedimentation.
This may bs accomplished by insertion and use of the central collector 62 described, positioned ben,eath the central influent jet 8~.
Its flow is radially inward below the influent jet boundary surface. Owing to the presence of an hyperboloidal diffuser surface or vane 60a, the 10 central effluent can operate with minimum degradation of the influent jet.
Moreover, it operates upon a well-sedimented, low turbulence fraction of 3edimentation tank contents. These conditions lend them~Qelves to the production of a consistent, predictable fraction of partially sedimented flow which reduces the tank overflow rate.
^ ~ 15 On the inlet to the intermediate level collector in the ~edimen- ;
tation tanks it may have the hyperboloidal profile of the upper diffuser vane ,., i .
60a since it is less critical in that flow i8 accelerating. On the system optimi$ation, more fully explained hereinafter, it appear~ that it is es~ential to~control the process, operated manually or automatically to accornplish 20 the desired flows stated above. Representative means 70 for manual or' ,~ I
automatic regulation are provided. lmplementation of ~ensors 72 for flow are an obvious requirement. One ~ y to determine organic load is to measure it by lab technique on typlcal days. The average hourly re~ults could be charted~. Control of means 70 could be based on the expectation 25 that this would occur. It is also possible to use inferential measurements ~- of load, such as those based on light transmission or spectral ab-sorption in n.arrow bands of wave length.
i-,' ~

~; ' ' .
.

Probably ra~icl, in~ells~ oxidation coul~ be accelerated sufEi-ciently to cJive rea~ time data on BOD.
'rhen, ~ystem control for manual or for automatic con-ditions may be based on an expected progr~m (historical ~ind-ings) modified by real tim~ measu~ements of the actual hydraulic and organ^ic loading conditions with sensors 72, for example.
This is a standard control technique in any servo system. The essential feature is to program; establish errors, impose an error correction and instrum~nt the result to make sure the error was corrected. If not, a secondary correction may be introduced.

FLOTATION SEPARATION
. . ~
This concept may be introduced with a secondary unc-tional effect of the central influent well 90. The affect is applicable where flotation, particularly for oil and grease sepa-ration is of concern. These condi~ions occur in primary sedi-mentation. To accomplish this result, presaturation of the influent with air as through injector 92 at pressure levels ex-ceeding that at discharge is desirabie. Outgassing of the excess air as the system is depressurized enables enhanced flotation in ~`
the influent well 90 of the primary sedimentation tank. This integrates equipment and methods of sedimentation improvement with those of gas~liquid mixing, both as set forth in the present invention.
The collectors 62 and 64 remove two cuts of flow from the settling tank and from the sedimentation effluent discharges from the overflow weir central collectors. The upper cut is taken from 6 inches to 30 inches below the liquid line which normally runs closely adjacent the top edge of the tankO The 3Q lower cut is taken from 36 to 48 inches below such liquid line.
The ma~or portion of intercepted flow amounting to approximately 2~3 the total is taken-from the upper effluent collector 62.
The lower collector ~4 removes the~remaining ~ow except for ,~

.

: . . ~ ' : . ' sludcJe ~nd i~s entrain~l liquld. Noxm~Lly, it will bc necessary for the effluc2lt picked up by collector 6~ to p~ss to another processin~ operation ~or further treatment. From the sedimenta-tion operation, the basic flow sh~et leads to bioprocessing.
The effluent flow in the sediment~tion tank is indicated by the arrows 94. The effluent enters line 66 through valve 70, up the influent well 90, driven by pump 68, and discharged from the top 91 of well 90, through screen 74 and into a spiral discharge by vanes 60a adjacent the top surface of the effluent level.
The diffuser vanes 60a are driven in a slow ro~ary motion by motor 110 which is supported on a bridge truss 112 which extends over the top of the tank. The motor 110 is of variable speed and appropriately driven for the correct latitude of the tank since the vortex for the effluent actually depends on latitude. ;~
Flow is control1ed by valves 82a and 84a, as best seen in Fig. 2 of the drawings, and at the inlet by valve 70.
The effect of the valves in inducing turbulence at the difuser ~ ;
effluent is suppressed by means of the hole size in the screens 73 and 74. It should be understood, however~ that similar oper~
ations occur at greatly reduced velocities in tank 24 which might cause the elimination of an upper effluent collector 64.
At the end of the vanes of diffuser 60a, the effluent is directed in close to a tangential d.irection in the horizontal ~;
plane. The vertical component of velocity is extremely low owing to deceleration in the diffuser. In view of the low velo-city, it is clear that sedimentation will occur in the diffuser Provisisn is made for continuous sludge removal. This lS done by operating the diffuser at close to zero buoyancy, a mechanical~
technique readily wit~in the skill of one knowled~able in the ;~
30 art. ;
The diffuser vane 60a is rotated a very slow speed, perhaps one revolution per hour. These serve as collectors of -;
finely classified ma~erial. The sludge is removed-through pipe ~
~' "

,,~

.. ..

93 in the c~ ral scction ancl O~lt throu-~h th~ tank ~ottom, a~
well as through a sl~ld(Je ~rough 95 and sludge conduit ~not shown) 9~.
It h~s been anticipated that the ~xtreme care taken in settliny tank desi~n may be upset by two factors. One is wind induced surface cooling and superimposed horizontal 1Ow~
The second is the density analomy in water which occurs at 4C.
The latter factor may have seve~e consequences in terms of ver-tical circulat.ion~ In addition, there is the usual effect of temperature variation on the density of water. For these rea-sons, the invention uses an air enclosure over the tank, as indicated by cover 102. This cover 102 mitigates the e-ffects of wind and temperature.
-At least one of the central effluent volutes 82 or 84 will be vertically adjustable, and probably both, so as to en-sure positioning thereof in accordance with the flow demands through he tank to achieve optimum performance.
To ensure light gravitational loading, the rotating -diffuser 80 will be supported peripherally at each sector by wheel 80~ running at fixed load on the bottom. The wheel load control may be set with a suitable type of spring loaded washers.
The secondary settling tank 26 receives effluent from the lower cut of the first tank 10. Its primary sedimentation in its diffuser will pass particulates of 200 mesh or finer in-~ .
to the tank proper. The described cut for particulates greaterin size than those passing a 200 mesh screen will be deposited and removed from the sedimentation which occurs in the diffuser 80 beneath the false bottom, as in the flow path 78.
In regard to flow, in the secondary settling tank 26, the hydraulic effluent is one-third the plant effluent. The tank proper is intended to separate, in two cuts, the coarsest effluent particles to those of less than .... ...............

.'',` ~`, -27- ~

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200 nlesh. In the upper cut of sedimented flow, two-thirds the effluent i9 removed. The lower cut of fl~w removes one-third th~ tank effluent, or about one-ninth of the initially impressed hydraulic load Oll the plant.
Only $his fraction of flow proceeds to the trickling filter or other BOD
5 reduction process.
ROU GHING
TRICKLING FILTER
.. .
The following discu~sion will involve the operation of the first bioprocessing stage, a roughing filter 36 commonly known as a 10 trickling filter. No di~cussion will be given to the aeration stage 34 impressed upon the ïnfluent, as this is covered in my copending applications. Bioprocessing operations are ~lespon~ible ' for the principal reduction in BOD.

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The element~r~ ~heory of a trickling filter is that ~n extended surface is provided usually using rock Eill, about 6 feet deep, on which a microbial plaque develops under pulsed film flow of waste liquor containing some dissolved oxygen, DO. The plaque is comprised of a surface-contacting anaerobic substrate immediately adjacent to which anaerobic and facultatlve micro-biological forms predominate. ~bove this layer, aerobic orms may be present. This implies a source of oxygen. Ostensibly, this is provided by an induced, vertical, natural-convective air circulation occurring parallel or countercurrent to the pulsed liquid flow.
A fundamental limitation of conventional trickling filtration is the indifferent oxygenation occurring therein.
In consequence, aerobic processes essen-tial to bioprocessing are inhibited. Diminished capacity in organic load reduction ;
results. A further limitation aggravates this problem~ It arises since, to allow some air circulation, hydraulic loading is restricted. This reduces the capacity of the filter and concurrently the effectiveness of waste trea~ment. This is so because the hydraulic compromise restricts 10w recirculation to the filter, a prime factor in deriving significant BOD
reduction.
To indicate the deficiencies of free convective air flow in trickling filters, it is of interest to refer to opera-ting conditions inducing such flow. A basic equatio~ for air velocity as- taken from Waste Water & Waste Water Engineerin~
Fair, et al, John Wiley & Sons, Vol 2, pp 35-13, is: -V a = 0.135 ~T O.46 where ~-V a is the air ~elocity in feet per minute and, :.
~ T is the temperature difference between the air and the waste water, F. -- -: , . .

lq.~
lle waste w~ltec-air t~mperature difference seldom e~ceeds 25F. For temperatu,re differences of 10, 3.4F, for example, V a is respectively ~1.0, 0 and -1.0 fpm. The posl-tiv~ sign denotes downward flow. P~ecoyniziny the filter ls a stone-packed bed about six feet deep, in no case is a ' realistic air velocity indicated~ Forced air circulation has been examined with little promise. Packed bed resistance to air flow can be high especially with superlmposed hydraulic flows.
The limitations of aeration and compromises in hydrau~
lic loading are unnecessary. The ideal remedy is u'se of an `~ ;
effective air-liquid mixing system in the trickling filter in-fluent line. This will provide D0 in the range of 7 to 8 ppm, all year round and at any hydraulic loading. The particularly- ~ ~
undesirable restriction of recirculation may be relaxed. This ; ' ,, simple remedy will enable hydraulic loading in ~he range from 1,000 to 3,000 or more gallons per sq~are foot per day~ Typi~
cal current practice is at about one-fifth to the lower range of these le~els. The hydraulic flows are restricted to these ~ ~, ,;' levels to defer-blocking of air flow which has been necessary - ,,~
to provide for aeration. Having eliminated compromises dic~
tated by inadequacies o~ aeration in conventional art a simple ~ ', ',' change enables full exploitation of the revised trickling fil~
ter process. This change is one of media, from a size range '~
of coarse rock to a reduced size range of smaller media. The'', ''~
,' change in media is primarily responsive to hydrodynamlc flowO ' ~ f, This is so because compromises relating to one f~ow are unne- ' cessary. Inasmuch as the change is in hydrodynamic character-'isti~s, it is conventional to describe the desired media pro~
perties in terms of hydrodynamic parameters.
The parameters of intere5t are the friction factor, ,the Reynolds number and the roughness coefficient. The media '- , size factor applies as an equivalent diameter.:, The . ' , ' ' , ' ~ ~
-30~ ~ ,~

.;... . ,, . . . . ........................ , . " . . . ..
.. . .. . . .. . . . . .

:l.t ~ 9L5 characteristic l~ng~h of flow path is th~. b~d d~pth, which is conventional. The relation among thcse factors i5 of the form:
f = N +b where f is the friction actor a is a constant NR is the Reynolds n~ber and b is the bed media roughness factor~
The definin~ equations of interest are f = 2g D~V 2~P , and -N _ De V~

It suffices to define the media in terms of its equivalent di~
ameter and roughness factor. Flow conditions are stipulated by the~functional relationship between riction factor and Reynolds number. ~~
The typical parameters for new mPdia are in the range tabulated next for a hydrodynamic or hydrofoll elements. This ~ -arises in relation to an influent waste with high DO and no aer~
ation reguired in the filter proper.
~ I have calculated a substitute plastic media, for ~`
example PVC. The media is extruded tubing. It is assemblçd in an equilateral triangular grid to maximize the surface installed , per unit volume. ,~
The tubes are spaced to ensure balanc~dflow inside the vertically positioned tubes and outside the tubes. This requlre~
that the hydraulic radius ~or the internal and external passage be equal.
A typical result appears as follows:
.: -OD = .~4 inch ID - .74 inch L ~ Grid spacing 1.16 inch The hydraulic radius of a channel is:

Area of section/perimeter .

~5~
The section descrlbed above exhibits an area for biological plaques of about 40 ft2/ft3. Conventional rock has less than ~0 percent o~ this specific surface.
The lengths may be full depth in a continuous section, from 6' -to 30'; however, shorter leng-ths stacked to the total depth have advantages. The basic advantage is that the laminar boundary layer of liquid on the microbial plaque starts at zero `~ -thickness and builds up. A length in the flow direction which is short compared to the length required to fully develop a stable laminar boundry layer keeps the dissolved oxygen supply ~-to the plaque readily available. The diffusion gradient is increased in two ways. First the concentration is sustained at high levels, second the boundry layer thickness is decreased.
The length for a fully developed boundry layer in -laminar flow is as great as twenty feet for water flowing in ~ ;~
tubes of about 3/4 inch diameter in the limiting transitional range of Reynolds number, about 3,000. Expressing distance in terms of diameter, the transition length is about 1/10 to 1/20 ;
the Reynolds number.
The flow in the spaced tubular media at the limiting ~
laminar Reynolds number may be estimated. It is 22 million ;
gallons/day per 1000 square feet of media surface. Hydraulic loading rates are conv~ntionally less than 1 million gallons/day per 1000 square feet. Thus, planned high hydraulic loading is feasible with this media.
Moreover, the uncompromised rates enable much higher organic loading. Instead of present upper limits of less than 70 pounds of BOD per day on each thousand cubic feet of media, three to four times this load appears feasible. The high organic or nitrogenous loading only becomes practicable with preaeration which permits much higher hydraulic ..... ......... . .. ..
:- -- : .

8~

loading. All three variables, D0, hydraulic loading and organic loading, interact. Becauae of thi~, only a mutually compatible solution i~
feasible. In this instance the equipment and method involved bring into action the integrated benefit of efficieng gas-liquid exchange and bio-proce~ing operation~.
The structural detail~ of the improved trickling filter utilizing a 134 rnedia described hereinbefore are illu3trated in Fig. 4 of the drawings which shows that a circularly-shaped housing 120 centrally mounts a carrying post 122 which receives the liquid effluent through pipe lZ4 carrying the aerated effluent discharge from the settling tanks. The post 122 rotatably carries a distributor arm 126 which is rotatably driven hydraulically by reaction or by a motor 128 connected thereto through ~haft 130 and double flanged coupling 13Z. The liquld influent through pipe 124 pa~ses up through center post 122 and actually distributes in a ~ .
~ 15 sprinkled relationship out the di~tributor arm as it is rotated by motor ;' 128, all in substantially the conventional manner heretobefore utilized in trickling filters.
In the particular con~truction utilized, some type of wire me~h to forma large c~rcular bed indicated generally by numeral 134 ~' 20 i5 filled with loosely packed stones or the specialized materials defined , ~
~, above that offer promo~e of providing greater surface ranges per unit volume. As long as the problem~ of plugged liquid flow and ~undue gas-phase 10w restrictions are con~idered, extended ~urface packing can be uaed effectively in this conf~gulation. In any event, the liqu~d ~ent out ùy -~ 25 distributor arm 126 drips down through the packed beds 134 into the open base.
:

' 8~5 In addition the invention may contemplate utili3ing a plurality of forced air blowerc, each indicated generally by nurneral 140 po~itioned around the periphery of the tank 120 and adapted to dri-re air in the dir-ection indicated by the arrows 142. Since one of the purpoaes of such a 5 trickling filter to reduce BOD i~ to in~ure more oxygen is present to cause oxidation of the liquid effluent, such forced air which mu~t neces sarily pass through the bed in a reverse flow to the liquid flow therethrough, forced circulation can supply oxygen to sustain aerobic metaboli~m.
Further, in order to provide the increased oxygen atmosphere, excess 10 o~ygen i3 actually injected into the effluent through pipe 144 into ~ome type of turbulent mi~cing chamber 148, as appropriately controlled through ~ ~ valve 146. Also, in order to make the filter operate on nearly 100%
`~ humidity in the atmo~phere, ~ome type of roof covering indicated gen-. ~ ~
erally by numeral 150 may be provided that is supported by a catenary 15 cable arrangement 15~. Hence, the tricklingfiltermayutilize 100%
relative hurnidity, forced air circulation, and an oxygen enriched atmos-phere because of the oxygen injection into the effluent. The increase in :
plant capacity and reduction in BOD is readily measurable with this setup.
In this aerobic process it is also apparent that the design 20 features described for improved sedimentation means may enhance the tre~atment system overall. In other words, oxygen injection into the sludge digection unit 2Z is contemplated so as to greatly enhance the operating capabilitie~ of that unit to produce safe sludge concentrations.
The invention might also incorporate the addition of excess 25 oxygen directly into the hun~idifed atmosphere through a pipe 160 as controlled by valve 16Z. The control of the amount of oxygen enter~ng 89~S

might be appropriately provided by a ~uitable ~ensor 164 as~ociated with the effluent output pipe 138 and operating in conjunction with a rate of flow instrument indicated by block 166, and an oxygen concentration unit indicated by block 168. Appropriate senaors 164a-d are associated with the rate of flow instrument 166 and oxygen concentration unit 168 to complete this setup, BO as to control the actual amount of oxygen flow through pipe 160 for the most economical operation of the sy~tem.
BIOPROCESSING SECOND STAGE ACTIVATED SLUDGE
An activated sludge operation may be the sole bioprocessing unit or a secondary element in a two-ita6e bioprocessing operation. It i~
unlikely to find activated sludge a~ the initial element of a two-stage bioproce~ing operation. This is in reCOgDitiOn of the sensitivity of activated sludge operations to fluctuating influent hydraulic or organic loads. Although not present typical practice, activated sludge operation~
may be adapted to handle fluctuating hydraulic and organic plant influent loads. This may be done by providing sufficient flexibility in circulation ~, :
,~ to accomodate independent balancing of hydraulic and organic load in-cident upon the activated sludge operation. This has been re~erred to before and wlll be discu~ed under system integration. ;~;
Regardless of the mode of application of the activated sludge operation, a predictable requirement exists for aeration. Observed aeration corresponds to from 500 to 700 cubic feet of air per pound of ` ~ BOD removed. The implied oxygen req.uirement is from 7. 5 to 10. 5 I pound0 of oxygen per pound of BOD removed. An equivalent quantity is derived from ~urface aelation. Thus, the overall conventional .
~ requirement for oxygen is froml5 to 21 pounds of oxygen per pound of : ~
~' :"
';

~3~ 5 BOD rernoved. Recalling that BOD equate~ one to one with oxygen de-mand by definition, the implication i8 that oxygenation by aeration using conventional techniques i8 not remarkable for efficiency. This inference remainds valid even allowing for available internal 30urce8 of oxygen 5 as fro~n the biological reduction of nitrates. Thi~ finding i9 to be expected since aeration efficiencies are often quoted in the range of 2%
to 10%. It should be understood that the quoted values pertain to aeration of liquid having an initial DO of zero. This yields the highest pos.ible efficiency. A more realistic efficiency is that for a DO ln the range of `,' 10 Z ppm.
~- The practical solution to the aeration que~tion in activated sludge operations is set forth in my cop0nding applicatlon identified above. The technique and equipment derives oxygen mixing~efficiencies in excess of 50%. Use of such aeration means in the present activated , .i .~ 15 ~ludge operation is visualized. Thi~ will reduce air compressor capacity required by as much as an order of magnitude and will cut drive power requirements to less than 1/2 usual values. This treatment method j . may be of any of the seven basic rnethods utilized in activated sludge ;', operations. ~hat is important is the integration of efficient gas-liquid i?ij 20 ~ mixing techniques with this stage of bioprocessing.
~;~. From the activated sludge operation, treated waste di~
charges to secondary sedimentation. Where the activated sludge operation is not preceded by sedimentation, the following sedlmentation operation . ., mlght properly be termed final sedimentation.

,1 25 SECONDARY SEDIMENTATION

In the ca5e illustrated in Fig. 1, the proce~sed waste from . .

. ~ :

"
, . - . . - - . .. .

89~i the activated sJ~dge operation i8 di~charged in a central influent as well as for primary sedimentation. Here, however, e~sce~s aeration to achieve degassing and enhanced flotation of grease and/or sludge i8 unneces~ary.
With this exception, the equipment and process operation rnay be ais de~-cribed for prin ary sedimentation previously. A~ might be expected, exceptions occur in the preferre:d di~po~ition of effluent from ~econdary sedimentation.
For example, ~edimented se:condary sludge i~ removed conventionally and returned to the influent of the activated sludge opera-~j .
`, 10 tion. Some of this flow is diverted 90 that excess sludge is fed to the .`:A ' " ~
primary digester. Clarified effluent i~ discharged to disinfection with diversion of necessary quantitie~ to secondary recirculation. To achieve ~:.
de~ired balance between the hydraulic and organic loading imposed by secondary recirculation, intercepted partially sedimented flow may 15 incorporated in the secondary recirculation. T~is is ~hown in Fig. 1.
'`~'1 ~! ~ In the cffluent from secondary sedimentation destined for disinfection, di~infection i8 initiated at the line exiting the secondaries.
1/ ` ~ -~
~, ~ This technique exploits highly efficient gas-liquid mixing techniques

3 described in the above-identified copending application. The diJinfectant ~proposed in ozone-oxygen enrichad air for several reasons. First, f ~ I thi8 disinfectant is effective with the ar ganic loads present in brief contact times. Second, this disinfectant i~

.

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potentiated, i. e., it acts Rynergiatically in the presence of a secondary ox~dizing system. The secondary oxidizing sy~tem may be ferric chlor-ide added in secondary sedimentation to promote charification, or it may be the standard chlorination additions. In either caRe, ozone-oxygen 5 enriched air reduces the ultimate chlorine demand and ensures an effluent exhibiting relatively lower chlorine residues with high dissolved oxygen. The disinfection characteristic~ of ozone-oxygen and potentiating effects of ferric chloride are noted. The standard technique adds ferric chloride to ~econdary sed~n~entation sy~tem ~o it cooperates with 2-3 10 added in disinfection.
DISINFECTION TREATMENT
According to the concepts of the present invention, a highly effective systemfor the disinfection of material is provided according to a two stage oxidative system containing a distribution of compound of 15 ammonia and ammonium and i9 particularly suitable for the treatment of :
waste or sewage effluent. A primary oxidizing agent it utilized to di~
infect the material as well as preferably to lower the pH level and a ~econd oxidizing agent is also utilized. Although the oxidizing agents may be any conventional compounds which are conventional disinfectants, 20 preferred comp~unds for the treatrnent of waste or sewage effluent cornprise aluminum chloride, or ferrlc chloride as the primary oxidizmg ag`ent and chlorine, chlorine dioxide, o7one either by it~elf or preferably in oxygen or air, and sodium hypochlorite as the secondary oxidi7ing àgent~. It ha~ been found that ~ynergistic results of oxidative disinfection .

,, . , . - -a5 are achieved by the two stage trcating ~ystem of the pre~ent invention wherein the primary oxidizing agent i~ utili7ed in the fir~t ~ta~ e and the secondary oxidizing ager~t is utilized in the second ~tage. Preferably, a fair amount of oxidizing agent i9 added to the first stage and a small 5 amount of secondary oxidizing agent need be added to produce an extremely low bacteria count.
Preferably, the two stage oxidative disinfection system is suitable for the treatment of waste or sewage effluent. The primary oxidi7ing agent may be added to the final clarifier influent or effluent and 10 the secondary oxidizing agent may be added to the disinfecting contact tank inflnent of a conventional waste treatment plant or facility or the wa~te treatment facility as set forth hereinabove. In the treatment of .` ::
~; waste and sewage effluent, a fecal coliform bacteria count of less than 10 part~ per 100 milliliters of treated effluent may be readily and 15 easily obtained.

~q~ The use of a preferred primary oxidi~ing agent as set forth ~' ~ above ha~ been found to reduce the pH level. Preferably, an amount of ,` ~ !"
primary oxidi~7ing agent is utilized so that the pH of the effluent coming ''.,',~ ' from the final clarifier is at a level of 7 or less with appro~imately 6. 7 - ` ' I ' :
20 to about 6. 8 being desirable. As apparent from Fig. 18, such a pH
level at ambient temperature~ will shift the ammonia~ammonium equili-brium to ammonium. In fact, substantially or nearly all of the equ1libriu-m will be shifted to the ammonium compound, that i~ in excess of approxi-mately 97% and at time~ even 100%. Of course, if a high pH is utilized, 2S ~maller amolmts of ammonium will be present. Generally any reduction . ~;, ~ ~ -38-,: :.
:~, :- :

S

in Ph i~ de~irable in that it recluce~ the amount of ammonia. I'hus pH of 8 and less at ambient temperature may be ~uitable. The ~ignificance of the reduction of ammonia is that ammonium chloride or other ammonium compounds or complexe~ often exert virtually no oxidative demands when 5 exposed to bacterial metabolism in the presence of oxygen below a pH of 7. 0. Hence, in the treatment of waste and ~ewage effluent, the nitrogen oxidative demand will be virtually reduced to 0. In contrast, ammonia exhibits a sub~tantial oxidative demand amounting to approxirnately 4 1/2 times the ammonia nitrogen concentration. Thus, in conventional waste 10 treatment ~y9tems wherein concentration of the ammonia in the effluent discharged from the secondary clarifier which i~ in the range of 30 part~
per million will require approximately 13S or 145 part~ per million of of oxygen demand. Not only does such a demanl exert toxic effects upon a stream or body of water, it al#o directly effects the di#solved oxygen lS concentration of the stream.
Concerning the toxicity effects upon a stream, it iB well known that ammonia in water can be toxic to fish at 4 to S parts per million concentration. On the other hand, ammonium compounds are not toxic and a~ previou~ly noted, frequently exert no oxidative demand.

. . .
~ 20 Additionally, ammonium compounds act as inhibitors of the exertion of .
nitrogenous metabolism by bacterial forms present. Thus, in addition , : , .
'~ ~` to the synergistic re:duction of bacteria in disinfection, the shift in :
equilibrium in the distribution of ammonia-ammoniurn to ammonium compounds produces hlghly practical results, especially in vlew of the Z5 regulatory ag-ncie~ requiring reduction of nitrogenous biochemical 39~
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s oxygen demand, and nlinimum practical chlorene concentrations consistent with disinfection and recent awarenes~ of the roll of chlorene in carcinogen formation.
In a conventional or typical municipal sewage treatment plant 5 handling primarily residential waste, an amount of primary oxidizing agent of approximately 85 parts per million has been found adequate to produce a pH range of about 6. 6 to 6. 7 and to effectively promote sedi-mentation in the final clarifier. A Ininimum amount of at least 50 parts per million has been found to be desirable. Additionally, the amount 10 of su~pended solids in such stage is generally ~rery low. Such suspended solids are precipitated in the secondary clarifier and thereby removed from the treated effluent strearn.
It has been established that in the above described two-stage ~ oxidative disinfsction system wherein n31atlvely hlgh amounts of primary .` 15 oxidi ing agents have been utilized, that very low amounts of secondary :
oxidizing agents are required. For example, where o~one is utilized, the concentratlon may be as low as 0. 7 parts per million whereas for chlorine, the concentration may be as low as 4 to 5 part3 per million to ;~ accomplish the aforementioned disinfecting objectives, that is fecal 2(~ coliform count of two or less per 100 ml. A8 a practical matter, the o7one feed concentration will generally be higher than the ~ninimum amount due to the fact of inefficient mixing in the secondary clarifier of the oxidizing salt ~uch as aluminum chloride or ierric chlorlde. Generally ~`-` ; a maximum of 10 parts per million will be sufficient to disinfect.
25 ~a~mum efflciency mixing can be derived from the use of high turbulence causing devices in a flow channel such as the utilization of flat plate ~ - `

- '- - - . - : . . . : . : . . : , - .: ., .
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8~5 orifices as above desclibed and utili~ing 3pecific arrangernents as set forth in Figs. 6, 13 and 15, of the preYent application a~ well a~ those taught in United States Patent NOB. 3, 730, 881 and 3, 805, 481.
Considering now an actual operating system according to the 5 present application, a firæt ~age of an oxidative disinfection or treatment with ferric chloride or aluminum chloride was accomplished by the addition of adding 85 parts per million feed. The fecal coliform count leaving the first stage was quantitatively established at 109/100 milli-l~ters. The fecal colofo~m count leaving the second stage of the oxidative 10 disinfection system with a chlorine feed rate of 4 parts per million was ., established to be 0. ~Ioreover, the degree of terminal sterilization ~:; effected i8 conIirmed by Agar C~ltures at 37C which indicate no growth.

Further, in the utilization of a two-ætage disinfection system a described above, it wa~ found that a fair size chloride dose added to 15 the first stage to promote sedimentation followed by a dcse of 6. 6 parts , : ~
per million of ozone in oxygen in a second ~tage can, in as little as 8 ~seconds, raise the dissolved oxygen concentration to 37 parts per million.
Such a æample was immediately sealed after oxidahve diæinfection and remeasured five days later. A dissolved oxygen concentration of 31 20 parts per million was found. The difference of 6 relates to the fact that the metabollc activity of the surrounding forms of bacteria present had been virtually completely inhibited. This was accompli~hed by direct di infection and by oxidative near kill which effected the viability of $he organibms and their abilityto propagate. Thus, the maintenance of the :! Z5 dissolved oxygen concentration of from 37 to 31 after five days tend3 to approach terminal diæinfection.

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o t~ rlM uhI sYs TEM
System optimi~ation in waste treatment is usually di0cu~sed in term~ of a fictitious con~tant load. Optimii3ation may not refer to meeting effluent quality standards at a minimum combined capital and : operating cost.
CHARACTERISTIC LOAI:1 The characteristic waste load on a plant i9 a combined hydraulic and organic load. It isi not constant during the day. It is likely to be : ` repetitive day to day, excepting holidays and weekends. Rain and i~ seasonal effects impose long period changes in load.
; ~ ~ 10 Weekday loads may be approximated reasonably well with a geometric series of few terms. It is not unusual to find that the range ;~ ~ in load may be as great as + 75% of the average load. Somewhat in con~
tra~t with this fluctuating load, effluent criteria on quality typ~cally ~!.' require that a prescribed maximum never be exceeded. Practically, t ~ ~
this means that plant regulation is aimed at achieving better quality with . 95 or . 99 probability. How much better the quality goal should be is i` 1 a critical economic con~ideration.
Obviously, with a fixed output specification and a highly ~; variable input, no fixed settings in proce~s regulation will approach 20~ ~ compliance and economy. A:n obvious~ approach is to accumulate mi~ced waste for extended time~ and then to treat a continuous sample at the averaae~ daily rate. Thisi would require Iarge holding tanks and problems~
of settling, ~epticity and co~it arise.
.. ``,`j!,,`'; ~ ~ ~ De~pite these problems, great advantage accrues from 25 the constant hydraulic and organic loading obtainable by optimum system :~ ~ - 4 2 -:;

s utili~ation. The basic advantage i~ in ~implicity of colltrolled, regulation of the plant process. The plant is e~entially a ~ervo ay~tem. To get a fixed output at a prescribed level, it would obviou~ly be easier to find the ixed proces~ setting~ to meet this level where the input i~ also 5 fixed. With the actual input, the best proce~s design and control is a then ~ophisticated problem. Althou~h, this problenl is a basic one economically, it has not yet received the attention it de9erve~.
In the equiprnent and process implementation of this concept, a dual attach on the de~ign and control problem i~ propo~ed. Basic to 10 the attaclc i~ provision of adequate flexibility in proce3~ control to enable a close approach to uniform hourly hydraulic and organic loadmg over a typical operating day. Thi~ minimi7es the ~nagnitude and effect o~ ~npo~d fluctuations in hydraulic and organic load. The second ba~ic element of approach i~ to~ provice process control to operate on 15 the suppressed load variations to achieve the desired level of effluent ,".,,5,~.,.".1",, j,j qualit~y continuously. Thi~ yield~ the optimum system in term3 of mini mized total cost to derive continuously the acceptable quality of effluent.
~; - Calculated performance, process condition~ and basic factors in total coat have been determined and are set forth m more detail hereinafter.
Z0 With respect to the system optimization the ideal solution requires excessive sedimentation tank capacltie~, both in the primary `, ~ and the secondary tanks. The practical answer is to compromise the flow.
The e~ample A, shows that for an arbitrarily varlent inflow~
- Z5 ~ rate and organic lcad concentration, it is possible to achieve a process .
: ~ :
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~(3i!~ 5 influent having a const~nt inflow rate and a constant c>rganic load concentration. The demonstrated condition pertains to the sedimentation tank influent in each example. Thereafter in the proces~, the hydraulic load varies with time, but the organic load concentration is held constant.
5 The compromise condition allow3 a variation in hydraulic and in organic load to the sedimentation tank. Lower total influent rates to primary sedimentation result. The design condition is imposed next in the process.
Thi~ means that the interval a-b overwhich integrals are considered is short `~ or that point values are used. In addition, a simplified on-off control ~. ;
10 to approximate the exact solution is shown. This substitutes a rectangular ` region for integration in place of the region beneath a trigonometric curve, or an actual plot of station load, hydraulic and organic. Case D shows that where Ql= 3 for the 24 hour day rate, a total flow of 3. 8 provides an optirnum system flow. The flow condition yields a close approximation 15 to con~tant organlc load concentration to the trickling filter, as ~hown i the graph of Fig. 11. In an activated sludge proce~, the concentration ..,~ ,.."i could be held con~tant by return sludge rate controls. Hydraulic load~
~, ~
would vary in either illustration of the solid graph Dl, or the dotted graph ;~

jp ~ D2 of C:;a~e D.

.`; ;~, ~20 Gase A -- Schematic flow ~heet shown in Fig. 10 illu~trates :~ `'.1 ~
conditions for uniform hydraulic and organic load with an arbitrary variable ~`.;, i ; incldent load. The figures shown between sections in Flg. 8 are the BOD
of the treated waste in ppm. Case A, al~o shown by the graphs of Figs. 8 and 9, uses proce~9 control of flow in Ql~ Q3~ Q4 and Q5 Q2 may be Z5 held at zero.

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Maximum Load -- Q - l.4 MGD B = 350 ppm.
Secondary recirculation for l0:00 AM/PM load.
P
I- (BOD) 83. l.Q ~ Q31 = l. 4 x 350 -I Q3 20 I. 4 35 ~ 83 1. 4 267 5. 93 - 1.4 Recirculation ratic~; R = 1. 4 = 3. 24 Flow to primary: 5. 93 MGD rate ., , `' ! : :
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Secon~lary recirculation for 8:00 ~nd 12:00 AM/PM load.
83 x 5.93 = 1. 1 x 275 +20 Q3 = 58 [483 - Q3]
` Q3 = 107, 5/38 = 2. 83 Ql = 4.83 - Q3 - Z, 0 Secondary recirculation, other flows, 7:00 and 1:00 AM/PM.
This i~ the average load condition.
83 ~ 5. 93 = . 8 x 200 -~ 20 Q3 + 5~ ~5, 13 - Q3]
and, if Q3 is r~ero:

5. 93 x 8~3 = . 8 ~ Z00 + 20 Q3 +58 [5. 13 - Q3] _ -492 ~34= 2~ Q3 - 58 Q3 ~ -Q3 = -34/38 = approximately -1. 0 Case for 8:00 and 12:00 AM/PM
83 x 7. 33 = 1 . 1 x 27 5 + Z0 ~23 ~ 58 ~6. 23 - Q3]
610 = 20 Q3 - 58 Q3 - -38 Q3 Q3 = 54/38 = 1, 42 42 4 . 8 1 III. Case for 7:00 and 1:00 AM/PM l~verage load.
83 x 7. 33 = . 8 x Z00 *Z0 Q3 +58 [6. 53 ~ Q3]
61Q - 160 - 379 = 71 = -38 Q3, but for Q3 = 0 .: . : -:; ' ; 20 ` ~ 71 ~ 58 Ql, Ql ~ 71/58 = 1. 23 flow check 6. 53 B + . 8 x Z00 = 83 x 7. 33

6. 53 :B = 450 B = 4go/6. s3 = 69 flow must shift to Qi +Q4 continued percent solids primary 25 ~ ` 3 % and percent solids secondar~ 6% `
` ~ Prlmar~ eludge 3~o at 7. 33 MGD = ~ 22 MGD
BOD = 83 58 approximately Average supplied ~ approximately 2500.

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s IV. 83 ~ 7. 33 - . 8 x 200 ~ 600 Q~ 58 r6. 53 - Q
~ 71 _ 600 Q4 ~ 58 ~
Q~,~ = 71/542 - . 131 MGD
thenQ1 = 6.40MGD
V. Conditions at 6:00 and 2:00 AM/PM
83~ 7.33=.5~ 125+600Q~,~$8r6.83-Q4]
151 = 600 ~4 - 58Q4 Q4 ~ . 279 MGD
Q1 = 6. 55 MGD
VI. Conditions at 5:00 and 3:00 AM/Pl~.
83~7.33'=.28~70+6OOQ4+58 L7.05-'Q4]
81 ~ 600 t~4 5 8 Q4 24 = . 33 MGD
~ ~:
~1 :: : Q1 = 6. 72 MGD
~ II. Conditions at 4:30 and 3:30 AM/PM~
;~ 3~7.33:=~.22xs5+ 2s00~ Qs+58 E~ ;Q5]
Qs = , 089 MGD, or showing alternative for secondary ~ludge mcthod of digeste~
supernatant ~ 83 ~ 7. 33: - . 22 x 55 + 600 Q4 ~ 58 t7 11 - Q~ .
~ ` lB6 -~Q4 L`600 - 58]

R4 - . 3~L3 MGD
Q1 - 6~ 77 MGD
Conditions at 9:00 and 11:00 AM/PM
83.~7.33 = 1.3Zx327+20 Q3+58~ r6 ~Q3]
VIII. Conditions at 8:30 and 11:30 ~M/PM
83- 7. 33 - 1.22 ~ 305 + 20 Q3 ~ 58 [6. 11 - Q3~
Q1 = 3. 11; Q3 = 3 0 ~ :
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~L~9X~il8~S

IX. Condition at 9:00 and 11:00 AM/PM
83-7.33 = 1.32 x 330 ~ 20 Q3 ~ 58 t6- 0 --174. = -38 Q3;
Q3 - 4- 58; Ql = 1. 42 X. Condition at 9:30 and 10:30 AM/PM
83 7. 33 - 1. 3~ x 345 ~ ~0 Q3 + 58 ~,5. 9S - Q~
-211. = -~8 Q3i Q3 - 5. 5 Ql ~ 0 4 Case A Pump Capacities -- Flow around primary ~edimenta-J, 10 tion equal~ gravity. F1GW around trickling filter equal~ ~ero. Fiow ,.- , around secondary sedimentation equals Ql ~ Q4 = 6. 4. Flow from see- ;
ondary ~ludge equals 0.4. Then, 0.400, 000. /24 60 - 278 GPM. Vse 300. GPM 2:150 GPM Secondary 6.4/1440 - 4,450.~ Use 4:~1200 GPM.
Equipment ~izing Case A
~'~ 15 Primaries: 4 ~ 60' Diameter Secondaries 4 ~; 60~Diameter Trlckling Filter 2 75' Diameter `
"'`'`''!' ~' : ~: System Characteri~tics -- Large sedimentation requirements.
Moderate Pumping requirements. Con~ervative bioprocessmg re-~0 1 20 quirements. Fixed effluent BOI) to chlorniation of 20 ppm, with influent BOD's from ~50 to 350. BOD reduction IS from 94. 3% to 43%.
A 3econd ca e may~ be examined. It reduces prim:ary and secondary ~sedlment~tion requirament3, as It appear3 that a practical variatlon from the illustrative Ca~e :A which has been described above, ~ : ~
25 ; Is~ ba ed on a compromise at the peak flow condition occurring at ~;
10:00 AM/PM.

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~he compromi~e i3 ~0 ~.ccept a syst~m conditiorl as at 9:00 or ll:oo AM/PM for the hydraulic load. ~n or~anic load in ppm can be held constant. Instead Oe the ideal situation, holding the hydraulic loa(l constant, 2~ hours per day, we hold the system hyaraulic load at the 9-11 level. Then, in the interval 9-11 AM/PM, i,e., twice a day, for 2 hours, a hydraulic over load is allowed. This only affects the primary and secondary sedimentation tanks, and not seriously, in comparison with the cost reduction enabled. Except in the interval 9-11, the sys-tem hydraulic and organic load may be held constant.
Of course, other compromise expedients may be selec-ted. For example, the interval might be 8-12. For the three cases, A, 9-10, 8-12, the relative flows are 1.4, 1.32 and 1.1~
Mos~ state laws require that sedimentation tanks be proportioned to accommodate specified overflow rates expressed as MGD per unit of surface area. Thus, reducing from 1.4 to 1.1 means that the required area reduction is 3/1.4 which is roughly proportional to the cost reduction.

, The all or none flows are typical of practical manual control. Valve settings may be made and le~t for an appreci-able time. This type of control is also amenable to automatic regulation of the plant. Simple time controls can accomplish this type of regulation.

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The previous di~cu~ion involved more 30phisticated controls typical of uYual servo control system. The foregoing condition~ are a convenience in calculation. The calculations aet forth above ~nd the graphs of Fig~. 8 through l 1 are based on control~ of definite integral~.
5 The integrals concerned ~re of the form:
Q = q c dt , where:
Q i8 an organic load a, b are tirne limits for the load increment considered q is a flow rate dt is differential time.
~. ~, i :
~; In effect, control is based on manipulation of definite integrals to approximate organic load concentration~ at indicated points in the overali proces6. A particular ca~e is shown at the influent to the sedimentation tank where the organic load and the hydraulic load are -~
15 held at constant values. The effect on increased overflow rates at . - . . . ..
~"'! ~ the sedimentation tank ha0 been noted above.
. . , To relax the overflow rates at primary sedimentation, it i6 feasible to ~mpose the condition for constant hydraullc and organic load ;
~ ~ ~ at bioprocessing. For a tricking filter or an activated sludge unit i~i ~' 20 operation, it is desirable to hold the hydraulic and also the organic load constant. This is particularly so of activated sludge unit opera-~; tions. To illustrate this condition, a limited number of calculation~ as ~, . .
set f orth above are indicated to show a typical solution.

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50_ ~ ~

~ ! _ 8i~5 DISINFECTION SYSTEM
The di~infection sy~tem indicated in Fig. 5 of the drawings i~
a gas-liquid m~xing sy~tem operating under a hydraulic pre~sure gradient. It is compriqed of a liquid oxygen ~upply 200, an ozone source ~: 5 or generator 202, an o~cillator power ~upply Z04, and a proce~s flow line indicated generally ',.. `i 10 ;

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:
-50a-;

by n~lmcral ~0~. Th~ line 206 opecat~s in thc regime of tur~
bulent Elow, at or abov~ a Reynolds ~ul~r of 3,000. High momentum exchange mixing elements are carried in at least cer-tain o~ the ~-shape~ flanges 208. These mixing elernents are normally flat pla~e orifices 208a which induce intense mixing sufficient to minimize radial concentration gradients in the processed liquid effluent entering the flow line 206 at 209.
The mixing elements 208a may be Eollowed by sting-type canti- ;
levers 210 driven by a tunable source 211 ~xcited at or near their natural frequency. These may be positioned in relation to the gas injecting means to further enhance the momen~um ex~
change in primary regard to minimizing concentration gradients occurring in the angular direction in addition to the radial gradient suppression induced by the basic mixing element, the flat plate orifice. In addition, the primary ob~ective is to have the stings 210 provide mechanical disruptive forces on .
flocs, plaques, or agglomerates which may be present in the :~
proaessed liquld effluent. The objective of imposing disruptive-forces is to reduce the size and to extend the a~ailable surface for disinfection on such flocs, plaques or agglomerates.
The orifices 208a in the T's 208 are provided at the flange joints as a matter of convenience. The orifice diameter ratio to the pipe diameter is typically equal to or greater than 0.7. In the T's 208 securing the orifices 208a, two other ele~

i:::, ~ ,, .
ments are mounted. One is an 3-2 injector 212. The injector 212 is introduced in a fitting ideally centrally allowing axial positioning whlch extends through the orifice perferabl~ to or `
slightly past the vena contracta formed by the flow through the orifice. Optimal injection is found to be with minimum concen-tration gradient in the flow direction. trhis is most conveni-ently obtained by making the fluid flow rate steady over short or longer intervals of time and by similar proportional control of gas flow. The sting 210 is the ............... ~................ ;

ll~B?~845 second element introduced with sin~ilar provi~ion for axial position and sealing as the injector 212.
The 3 ~ 2 injection occurs at approximately 5% or less con-centration by weight of ozone in oxygen. For generalized disinfection, it 5 is introduced in amounts greater than 0. 5 rnilligrams of ozone per liter of fluid. The injected concentration will attenuate in the flow line. Two factors cau~e the attenuation. One i5 the decomposie~on rate for 03 in water leading to 2 The second attenuating factor is the oxidation load of the material contained in the processed liquid. In the typical 10 wa~te, thi~ is comprised of organic materials incompletely oxidized to stable forms. These material~ in conjunct~on with o~idizable inorganic conRtituents comprise the BO~ load o waste.
Recognizing that 03 attenuat1on whlch Wl11 occur, it may be necessary to utilize sequential injection. This aspect i~ shown in Fig. 5.
15 Fig. 5 also indicates a series oi test points ~in the flow line between injection points for the 03 which include sen30rs 214 that act to control a power supply 204 to the generator 202. These Rensors 214 are useful to . ~access quantitatively the 03 concentration and the BC)D reduction. For agivenReynold~ number, thes2 dataprovide informationontime and ZO position. This information ~i8 essentia} for design of the flow system -and for determing the optimum 03 injection flow rate. For generalized disinfection; it i~ important to the invention that the injection rate and interval be such that the at tenuated 03 concentration exceeds O. 5 milli-grams of ozone per liter of efiluent at all points in the system in which 2S generalized disinfection iB to occur. In contrast, speciali~ed disinfection ::

8~5 as of obligate anaerobic forms of bacteria m~Ly be sustained with air or oxygen containing only trace quantities of ozone as usually found in concentrations of 0. 01 ppm or les~. This proce~s and implementa-tion is detailed in nny above identified copending application.
From the above, the purpose for sequential injection is clear.
The number of points, or the di~tance or time in the flow line will depend upon the impresaed oxidation loacl and particulate ~ize of this load. It is anticipated that in normally operating ~yste~ns, the time for processing will not exceed 8 minutes. It should be under~tood that the piping sy~tem indicated in Fig. 5 will normally extend in a vertical dir~ction wherein the entrance at 209 and discharge at 216 are at com-parable horizontal location~ so that in essence a hydraulic gradient i~
present when considering the system a# a whole. The relative vertical location of thèse points is immaterial to the effectivenes3 of the di~
. ~ : .
lS infection system.
' The actual construction of a T 208 showing the flat plate orifice 208a, the centrally positioned 2 ~ O3 injector 212, and the oscillating ;
~ting 210 in greater detail is shown in Flg' 6 of the drawings.
The invention also contemplate~ that excess oxygen can be picked ~off the piping system at point 218 by a sultal~le pump 220 and sent into a drier 222 for tran3fer therefxom through a control valve 224 into the ~ ~
supply line from the liquid oxygen source 200 to the ozone generator 202. ~;
A suitable power supply 226 activates the drier 222.
~: Ab absorber indicated by block 230 might be included to receive the output from generator 202 hefore passing the ozone concen-trated fluid into a supply line 232 so as to remove all excess oxygen :

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with the excess oxygen fed back over line Z34 and through valve 236 to the supply to generator 202. The absorber 230 i~ optional as the 3 ~ 2 concentration can pas~ directly through line 238.
ln some in~tances, it might also be de~irable to have proceased - ~ ~ 5 liquid effluent entering at point 209 into the piping system 2û6 pass through some type of deaerator or abaorber to degas or desorb 2 out of the effluent ~ince you can't get new 03 into the fluid in an 2 carrier gas if ~he fluid is saturated with 2 A dotted line 240 illu~trate~ this optical arrangement. ;
~ ;
, 10 It hould be under~tood that the system described hereinabove ;~
~` calls for the preferred implementation utilizing a liquid oxygen feed. An oxygen enriched air feed to oz;onation may be used with or without re-cycling and oxygen make up to be described hereinafter. E:ithe~r of these may be refined incorporating recycled, dried, and recovered oxygen.

i~; 15 However, continuous recirculation may not be feas~ible, and in this case it ia apparent that t~lere exists a desirable bleed-feed rat0 for the oxygen supply. The rate should satisfy the DO requirements on effluent and the ; argon dilution problem whereby ozonation efficiency may degrade with increasing concentrations of contaminant gases . Also, the in~talled 3 20 capacity of the bleedfeed 2 supply should be at the average anticipated 3 - 2 demand. This w~ll minim1ze the capital 1nvestment~required.
With reference to the passage of the effluent th~ough deaerator , o* ab~orber 230, it has been found that 7 to 40 ppm may be recovered from the effIuent before discharge for use m the oxygen enrlched process 25 ~ ~ in the waste ereatment system. Other techniques other than deaeration ., ;:;

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LS

or desorbing that might be utili:;ed wDuld either be heating or cavita-tion, where the cavitation might involve ultraRonic excitation as set forth in ~ny above identified co-pending application.
It should also be noted that the entire disinfection proce~ set : 5 forth preferably u~es oxygen enriched air, not air, thus minimizing the impact of high nitrogen concentration or ozonator efficiency. In using oxygen enriched air or oxygen a~ described, a number of signi-ficant improvement~ naturally follow. For straight oxygen it i~ a known ~ physical fact that the potential _olubility of oxygen in water if five or ''' :; :
six timeR as ~reat if introduced in equilibrium for oxygen enabling a ~- higher concentration of ozone to be injected while le~s oxygen i5 ;
required. T~e elirnination of oxide~ of nitrogen contributes to safety and ; ~ ~ air pollution control. Further, the availabillty o oxygen for recycling `~! ` and for process enhancement reduce~ the oxygen expense by an order `'` ' b 15 of magnitude or more while the proce~ enhancement is increased as pointed out above.
Also, recovered oxy~en may be utilized in the triclcling filtsr or activated sludge operation by oxygen-efiluent injection, or by enrich-ment with thi~ oxygen of a basic a~r-effluent injection means. In this 20 ` way a tricklmg filter bed should maintain aeroblc metabollc rate~ at maximum quantitative levels throughout ita entlre depth. A similar ~ ~;
ffect~ on the activated sludge operation i~ po~sible. The effect on increa~ed ;BOD reduchon is apparent.
FORCl~ MAIN INJE~CTION
The aeration for force main injection has been practiced in the range of 4 parts of air in from 10, 000 to 100, 000 parts of fluid by :~ :
:

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weight. The volume concentrations need not exceed 50% of air in liquid. For force main injection, useful results may be realiz~ed to much lower levels, perhaps as low as 1-5% by volume. Wet well aeration may be effective at appreciably lower feed rates. The limi-tation for this case depends on degas6ing at the impeller eye, lèading to eventual lo~s of pump prime. This problem is more fully covered in my above-identified co-pending application.
The ~aturation level~ for aeration of water are near 20-30 parts per million by weight. For wa~te, somewhat lower saturation limits may ~ ~;
be expected in view of the presence of additional contaminating gases and dissolved material~, i.e. for aeration. In the oxygenation case, water saturation levels are in the range 40 to 5 ppm, by weight. For ozonation, with oxygen a~ the carrier, at 6~o ozone in oxygen by weight, , ~, ~he ~aturation range corre~ponds to ozone in liquld concentration~ of ~ about 2. 5 ppmj by weight. The foregoing ranges may be useful as~
depicting preferred ranges of gaY concentration.
As is shown, force main operate intermittently according to . the influent rate to the wet well and the level settings u~ed to control the pumps. When the pumps shut down, a pressure wave travels through ~ri 20 the system, i~ reflected, returns, and oscillates periodically ulti-~;1 mately damping out. The pre~sure fluctuations occur below and above ``1 the~static pressure level in the line. The pressure ditferences may compare~ with the dynamicstatic pre~sure difference or they may ~` ~ exceed this difference. Such pre~sure wave~ are referxed to as water hammer. ~Air present in force main incident to aeratlon to control ~ .

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septicity affects these pre~sure wave~. The pre~ence of air reduces the pressure difference~, it reduce~ the velocity of the p~esBure waves in the force main, from one end to the sther and the air damps out the pressure oscillation rapidly in a reduced number of cycle6, all in comparison to the force main re~ponse to pump shut down without air injection to the force main. All these results are beneficial and are a bonus accruing rom the practice of air inJection to force mains. Thus, it i9 apparent th~t force main used for waste, water, or liquid generally, such as oil, may benefit from aeration, or inert gas injection aa with engine or boiler exhaust gas, nitrogen or carbon dioxide. Preferred gases are tho~e which are not unduly reactive and which exhibit low ~aturation levels in th~ liquid transported. This reduce~ the gas compressor capacity required to inject an exce~ of gas beyond the saturation con-` centration. The beneficial results on pressure reduction occur pre-~, 15 dominantly~from undlssolved gas.
SURGE SUPPRESSION
Pipe ha~nmer or surge suppression can be ~abated or greatly h~
` reduced by in~ecting an amount of gas in excess of the ~aturation levelof a gas in a liquid. Desirably, a large-excess i8 preEerred such as Z0 from 5 to I0 times the saturation level. Generally, an excess of twice the saturated 1evel 1~ nece~6ary to produce suitable results.
Preferably, to en~ure that the ~aturation level iD ~reached, the gas 1S ~ ;
mjected at~a h1ghly turbulent reg1on of flow in a liquid piping sy~tem ~uch as a mam or transmis~ion line as exemplified by a pipe. Generally.
~ any type of devlce lor causing high turbulence may be utilized. A

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specific example of ~uch a device i~ illustrated by Fig. 6, previously described. Although Fig. 6 Ahows a Tee with one portion blocked off, the same apparatus may exist in an elbow or the like or desirably in a straight flow pipe. According to the pre~ent invention, gas injector means 212 injects a gas into the central portion of the flow pipe of a force main or transmission line within or slightly past the high turbu-lence regime of a high turbulence cau~ing device such as a check valve or in the vena contracta formed by flow through orifice Z08a. In such an area, any longitudinal and axial concentration gradients are minimized. A aecond mixing orifice downstream at a tran~ieion length ` `i or rnore tend~ to suppre~ radial concentration gradients.
Yet another type of a high turbulence causing device or member containing a gas injecting member is shown in Fig. 13 which is des- :
cribed be~low in detail with respect to the injection of a polyelectrolyte ' 15 resin solution. Short tube 145 within a flow pipe or tube l47 ~cau6es ~ ~
a region of high tu~ >ulence mixing. The entry into the short tube section 5 is a flat or blunt 90 annular flange 151. The location of the in-'. ~ jection member or tube 153 is preferably at the ~Tena contracta of the ~,` flow. Preferably, the tip of injection tube l53 is located in the center of `l 20 short tube 145.
Another exampIe~of a high turbulence caus~ing device in this case containing a gas injector member 19 ~hown m Fig~. IS. In Fig. lSa,~
an inj~ect~on mixing elbow generally indicated by the numeral Z22 having . i ~ - :
an orifice 224 is located with the elbow at the commencement of the Z~S : ~ radluo. A plpe 2Z5 Is attached to the elbl~w in any conventional ma~ner.
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A arnall diameter pipe or rube 226 i~ inerted throu~h the elbow and through th~3 orifice 2Z~ 90 that the tip 232 iB located within the high turbulence and desirably at or near the vena contracta portion down-sitream of which full mixing occurs within the flow line or pipe generally S indicated by the numeral 225.
The location of the tip Z32 of small injection pipe 226 ii3 important with respect to thorough mixing and suppres~ion of concen-tration gradient~ . Generally, tip 232 may be located from about 0. 25 to about 0. 5 pipe diameters downstream or at a highiy preferred distance - ,~ 10 of from about 0. 36 to about 0. 39 diameters with about 0. 375 diameter~
~: being the optimum location.
A flat plate orifice which may be utilized in the elbow is shown in Fig. 15c. Generally the orifice diameter i5 from about 0. 7 to about ' 0. 9 of the conduit diameter and may have a taper (at about 60) leadïng . i 15 from the orifice opening. In Fig. 15B, orifice 2Z4 i~ located within a .
ni coupling or union, generally indicated by the numeral 310j, ahd connects ,~i the pipes or conduits 301.
" .~ .

~, 20 ~, ~
~"i, 2S
:~ ` ` ` ` :
~59 , ` ~ ' ~ h ShOWS the flat plate orifice in a coupling.
0~ course, the orifice can be utiliæed at numerous locations such as tees, elbows and ~he like or simply in a straight por-tion o~ a conduit.
As should be apparent to one skilled in the art, numerous types of turbulence causing devices containing gas injectors such as small pipes may be utilized. However, in situations wherein the monetary expense of gas injection into a pipe or the like is low, high mixing efficiency as ~xempli~ :
fied by optimal, i.e. fla~ plate orifices with coaxial injection ~
may not be required. Rather, it is suficient to inject an ~-amount of gas into a liquid such that the total amount of gas is in excess of that required to reach saturation within the ~ -flow pipe. Thus, the gas may be injected as through a normal -straight portian of a pipe line or in many other locations such ~ ;
as at a check valve following a pump, in tees, elbows, valves or wherever turns-or fittings cause turbulence.
Preferably, turbulence causing devices such as ori-fices or turbulence causing fittings or turns are located down-stream throughout the liquid flow system preferably separatedby at least one transition length e.g. from 25 to 40 pipe dia-meters for turbulent flow and preferably more than 40 diameters to maintain the saturation level of the liquid or to cause the saturation level to be reached where it is not reached through the addition oE the gas through a non-high turbulent area as ~`~
~ ':

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~ ' ~Irougll an cl}~ow. ~rhe ~rnount ~Incl number of such devices will ~ --depend lar~ely upon the system utilizecl as should be apparen~
to one skilled in the art.
The net effect of the addition of an excess amou~t of gas above the satura~ion le~l of the liquid is to provide a distributed air chamber along the entire length of the flow pipe and sys-tem which acts as a distributed surge suppression air chamber rather than a discrete air chamber. As above noted, preEerred gases are those which are not unduly reactive a~d which exhibit low saturation levels in the particular li-quid transported. of course, numerous gases may be utilized.
Specific preferred gases generally include: oxy~en; ozone prefPrably in a carrier gas, e.g. air, nitrogen, etc; nitrogen;
carbon dioxide; air, natural gas, exhaust gas, e.g. from a diesel engine driven pump, distillate gases such as propane, ~;
butane, pentane, etc. and the like. ~ ~ -Although the above described surge suppression system may be utilized in generally any liquid flow system, it has been found to be particularly suitable in suppressing surge 20 pressures in any liquid transmission system such as the flow -~
system of a waste treatment facility such as set forth above and may be added in the force mains.
AERATION OF MUNICIPAL COLLECTION SYSTEM
- A dispersed municipal collection system was equipped ' ~ ,' . ' ~,:
.

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,~
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4~i with aeration equipment according to the principles ~et forth. Before aeration, waste received at the procesEIing plant was septic, exhibited zero or trace dissolved oxygen and exerted no demand on oxygen satur-ated in the waste after it entered the plant.
In contrast, after all force main~ and wet walls were aerated, the dissolved oxygen of received raw wa~te reached 3 to 4 ppm. The waste was treatable as indicated by its oxygen demand of more than 10. 0 ; ppm per hour. The dissolved oxygen content sufficed to sustain aerobic ` :, conditions throughout primary sedimentation. The effluent from this first stage of processing 3till exhibited a dissolved oxygen concentration exceeding l. O ppm. These re~ults dramatically attest to the efficacy of these teachings of aeration. The desired suppres~ion of odor from septic decomposition was a noticeable further result.
, ~~ CHLORINATION
.`` 15 It should be under~tood that the invention further contemplates ,~-.;. j th`at chlorinc mixing utili ing the flat plate orifice~ and injection at 1 numerous points under high momentum exchange mixing conditions is clearly possible. The u~e o chlorine in a ga~eous sta~e for gaseous .l mixing injection or as a liquid solution is contemplated by this inven-` ~ ZO ~ tion. Fig. ~1 illustrates more typical points of injection for a chlorine ~, `1 :
~ ~ and water solutiRn~Shrough line 40 into line 36 to the effluent from the . .......... .
secondary sedimentation tank ~4. Further, ~he invention quite definitely contempiates the ;injection of chlorine in the disinfection portion 38 of s~ ~ ~ Fig. 1.
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lU~3~84S

SEDlMENTA TION
Th0 invention contemplate~ the injection of alurninum chloride or some other suitable sedimenting a8ent into the effluent at some point in the proceRs preceding the final disinfection contact element to assist in clearing the water when it i,R finally di~charged into a receiving Qtream, river, or the like. With the use of aluminum chloride, the invention contemplate~ the injection of about 2S to 100 partfl per million, with this being followed by a polymer iniection after a delay of two or three minutes. The aluminum chloride injection might take place for ~` 10 example in a somewhat rectangularly shaped trough 135 mounted In the bottom o the trickling filter tank.l20 of Fig. 4. Thi~ t~ough 135 `~ would collect all the water which trickled down through the filter media and then be passed through the ou~put line 138. In order to inject the: aluminum chloride into the effluent at this point, a plurality of ;:
~ transversely extendlng pipes 137 are mounted to extend acrosR the :
i~ trough 135, again as best fleen in Fig. 14, with the aluminum chloride ,, ~
, injéction being through:a pipe 139 which individually communicateR with ;~, each of the four pipes 137 Illustrated in Fig. 4.
Further m~xing of the aluminum chlorid0 is then followed in it~
..2Q passage of pipe 138 by entry mto a multiple short tube section indicated ~;:
by numeral }41 which iQ primarlly designed for mixing. In addition, '. because of the ~low flow rate through the trough 135, the~ injection of a polyelectrolyte resin may be made with coaxlal injection into the ;:
: vena contracta, into the end of the multiple short tube section 141 to ;
~: :
`~ 2S achieve the afiect of a flocculating agent as is well known in the art. ~ ;
~ :

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388~5 The ~hort tube effect~ a highly effective mixing arrangement. A
single ahort tube i8 illustrated ~chematically in Fig. 13, and is illu~-trated generally by the numeral 143. The tube in effect comprise~ a reduced diameter short tube ~ection 145 which is coaxially mounted within the outer normal diameter tube section 147 Th~ entry into the short tube ~ection 145 is with a flat blunt 90 angular flange 151 so that considerable and extreme turkulence iB present within the ~hort tube section 145. The injection of the polyelectrolyte re~in, or any other suitable resin might be through a ~mall ~nJection tube 1~3 which is positioned BO as to be approximately 0. 75 diameter~ of the ~mall tube 14S from the entrance with the flow being in tha direction of arrow 155.
Thus, with the short tube, it should be under~tood that the entrance from the tube creates a mixing, and that ~uch ahort tube~
~, .
can be po~itioned coaxially or rnay normally occur in existing conduits ~; 15 or extensions of existing conduits. For example, in the ~ection 141 : ;
it i8 contemplated that perhaps three short tubes would be arranged in ~ ~ide by ~ide bundle relationship with flow being in one end of one .~h~! ~ down through and reversing its direction a third tiTne to pa~s out through ~ i . ij ; ~ a third short tube with flow being in parallel. This particular short ~1 ~ 2.0 tuke arrangement might actually have a total length m the three ~hort ;~
tubes o twenty diameters of an indlvldual one, and preferably should not have le~s than a ten diameter length.
~` It is, however, desirable that the mixing be accomplished under `I ~ a low shear condition, particularly or the polyelectrolyte resin :-.:
2 5 ~ whlch ~hould be inserted at between . 2 to . 6 ppm and between l 1¦2 to 3 l/Z minutes following the injection of the aluminum chloride.

:: ~
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It should be fed at an actual concentration of .1% or le~s in water.
Again, with reference to the ~hort tube, the transition length of the tube should be greater than . 5 and preferably b~tween about . 75 to about . 9 with these figures being the ratio of the orifice diamèter to the actual diameter of the large flowing pipe or pipe 147 in Fig. 15.
In other words, the length of the tube should be a~ close to 25 to 40 diameters, a coInplete transition length, as possible.
In actuality the stream within the short tube of Fig. 13 if flowing under high pre~ure i9 probably contracted somewhat more for ; 10 a given depth of water or given pres~ure head. ~e have found that~the best length for the tube 145 should probably be about 2. 5 diameters.
Under these conditions, the head 10BB is O. 328H where H is hydraulic head upstream of the tube if the tube 14~ is vented, it may allow full flow through the tube rathe.r than the contracted flow defined~above.
However, we ha~re found that no venting of such tubes needs to take

7 place. Actually, for most efficlent mixing, a non laminar flow through ..... ~; - :
the tube 145 i9 highly desirable.
~, ~
The~use of the short tube also is achievingmixing under a hydraullc gradlent, rather than a gravitional gradient, and in this ~:~ zo manner, high efficlency as well as saturation above exi~ting levels in gravitational~ systems is definitely achieved.
Another important aspect of the introduct~on o~f gas into the J`'. ~ i system by inserting more gas than that r~ uired to saturat~ the liquid downstresm of~the pump is that pump prime i not lo~t, but that in this manner pipe knock caused by pumping ls slgnificantly dampened.

` `; 65 _ , .; .. .... .. . ~ , . . . ..

NITRIFICATION
Standard proces~es involve carbonaceous BOD reduction.
~Iowever, new state and federal requirements are being irnposed for nitrogenous oxygen demand or NOD reduction, or NOD. The process defined above, and particularly that as associated with Fig. 1 of the drawings as being the optimum sy~tem uses either all nitrification teaching, or all break point chlorination, or a split ~omewhere between these two. Preferably, the system should be ba ed on a two stage trickling filtration with return of stabilized digester supernatant. This makes the trickling filters convert all the nitrogen to ammonia or NH3.
: , NH3 is then separately oxldized to nitrate, or N03 or by break point chlorination to monochloramine.
` The oxidation of the NH3 to N03 requires four to five to six times the NH3-nitrogen concentratlon currently available in present ;1 lS sy3tem6. Specifically, this amount6 in the aystern designed above to 140 ppm of oxygen. Thus, for properly aerated waste with oxygen, a closed extend3d out fall line would allow ~the oxygen u3e to achieve the ; breakdown of the NH3 to N03. This would preferably be done before disinfection, and iB shown by the CL2+ H20 injection over line 40 in `! 20 Fig. 1. Then, disin~ection would occur after nitrification. It 3eems ` ` more practical to utilize a suppiemental aerobic process such as anaerobic nitrification unit as described in this specification.
In this umt effluent may alDo be under a pres~ure in its flow path, so that it will be under several gravities load, for example.
:,,, :
25 ~ Under this processing condition, much greater concentrations of gas or fluid can be saturated thereinto. The effluent would be maintained , !

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~UB~4S

under pres~ure ttntil processing was fully completed. Aeration i8 belie~red to be mcre efficient and ea~ier under ~uch a pressure system.
The vario~t~ embodiments of the pre~ent invention can be utilized to achieve an optimum process for the conversion of ammonia to arnmonium nitrates, particularly in waste or sewage treatment plants.
In general, the ~econdary treatment effluent from a waste or sewage treatment plant can be fed to a nitrification tower and treated in a manner and method as set for~h in Water and Sewage Works, Augu~t, 1974, Pages 92 - 94 which is hereby fully incorporated by reference with respect to the manner, processes, equipment and techniques ~; ~ utilized to produce low ammonia effluent including the utilization of a plaqtic media triclcling filter such as Surfpae supplied by the Dow Chemical Company. Utilization of applicant's various apparatus processes and technique will result in an improved process with the production lS of even lower ammonia effluent concentrations throughout the year.
,i According to the concept~ of the present inventioni the secondary treatment effluent may be fed to the nitriflcation tower through a dis tributor arm hereinbelow described in detail~ The primary advantages ;1 of utilization of this distributor arm is to diRtribute an even amount ~ !
of effluent to each area or square foot of the nitrification tower, :
regardlest- of whether it is located near the center aE the tower, at a , ` ,~ mid portion of the tower or at a radially outward point. Thi~ results in an improved efficiency of distribution and hence better utilization of available area for nitrification.

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:`

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-The secondary treatment effluent can be aerated for feeding to the nitrification tower. Aeration or the introduction of dia~olved oxygen into the effluent can take place in a manner set forth hereinabove. A
preferred introduction is the utilization of an injection nozzle into the conduit within the vena contracta portion of a turbulence causing device such as a flat plate orifice as taught hereinabove. A preferred amount of oxygen is from Z to 5 parts per million parts of a secondary treatment effluent. The provision of the oxygen, of cour~e, promote~
nitrification or conver~ion of the ammonia to nitrate.
Another aspect to improve the conversion of ammonia to nitrate ~ ~ involve~ the utilization of packed media within the nitrification tower ; ~ as hereinafter described such as Berl aaddles, pall ring~, and the like or the specialized media described above wherein the hydraulic s radius of the external flow channels ia sub6tantially equal to the hydraulic : ,., : :
; ~ ~ 15 radiu~ of the internal flow channels . This provision insures thorough !~-"r~ and efficient mixing and hence a greater conver~ion. Although the ,r,~ " plastic media trickling filter ~Surfpac) or rotating media (BIOSURF) may be utilized, the packing media having the hydraulic parameter of equal ., .~, :
h internal and external hydraulic radius is preferred.
., j .
&enerally, due to temperature difference, it i~ harder to i produce a satisfactorily low level of ammonia effluent ~uring the ~nter period then it is in the aummer. Hence, ~nother expedlent includes the : `~ ,, . : .
: . ' . ~

~6.~ 5 provi~ion of in~ul;~ting the nitrification tower to sustain warm effluent temperatures and this iq facilitated by minimi~ing the ambient air flow through the packed bed which would otherwise ~uppress reaction rates owing to the cooling which would be induced. This air flow is unnece~sary 5with an aerated inflow into the nitrification proce~3.

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_ _ _ _ . _ rrhe arrangement of the over~ll units of Fig. 1 can function in waste treatm~nt. One mode of operation is to allow all elements to float on line as the influent hydraulic and organic load changes. Typical changes in these two loads ~; ;
are hlgh. In terms of an average daily load, the range may be as great as -~ 75% of the average load. ~egulatory authorities usually stipulate that at no time shall prescribe~ limits for effluent-quality be exceeded. With a highly variable input load, this means either-that the process must be controlled to over treat waste most of the time, or that relating sophisti-cated control is neces~ary to achieve the necessar~ degree o~
trea-tment at any time. Both capital and operating expens~s are lower in the latter case. However, the usual enginearing unit tends toward the former technique. It is the approach and simpli~ied controls and regulation to achieve a degree of treatment satisfactory -for a fixed design condition. For any other input loading, effluent quality will ~ary.
Tests have shown that using the system with the sedi-mentation tank defined herein the DO level to the tank is about2 to 3 ppm, and out of the tank about 1 to 1-1~2 ppm to defi-nitely maintain the aerobic condition. This aerobic condition remains between 20 to 40 minutes after the effluent leaves the ,. . 1,~
sedimentation tank. ~

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-70~
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SCI~UU~EE~
AccoLcling to the concepts oE the present invention, a scrubber including an air washer may be provided for puri-fication as in the deozonation of an o~onated gas. That is, the residual or wlreac-ted ozone from the sewage waste treat-ment facilities as above set forth may be treated to effective-ly remove the ozone from the gas medium. Whenevex a scrubber is utilized, it is to be understood that a washer may also be utilizedO
A two stage scrubber, generally indicated by the numeral ~50, is shown in Fig. 16. Scrubber 250 may generally be any conventional scrubber and therefore contain a packed media 252 such as Raschig rings, Pall rings, Berl saddles, single spiral media and the like. The treating medium may be inserted at the top of the first stage of the scrubber, through reagent feed line 253. ~he treating medium will, of course~
trickle down through the first stage and collect in dxain 254 from which it flows throu~h drainline 255 to a make up tank 256. The treating medium may then be recycled by recirculating pump 257 or a portion may be discarded as through waste line 258. Make-up may be supplied to tank 25~. A reagent supply tank 259 having a pump 260 may be located to discharge to an injection-mixing system on the pressure side of the recircula-tion pump 257. Reagent make-up to the metering pump sump may be contxolled by float or other sensing means. Sensing may detect a reagent or treatin~ medium parameter.
The fluid to be treated in the scrubber is admitted to one end of the scrubber as indicated in Fig. 16 and has previously .'~

,' been thoroughly mixed and the contaminant i9 to be rernoved a~ through the use of hlgh solubility fluid~, decomposing fluid~ or fluids catalyzed to promote decomposition, or oxidi~ing agent~, or reducing agentP. The gas to be removed or decompo~ed with respect to the above-noted di~-S closure may be ozone. From this ~tage, an o~one-free fluid is then admitted to the second ~tage.
iALthough not shown in detail, the second stage may be identical to the first stage in that it contains packed media and contain~ neces~ary tanks, lines and pumps for supplying aeration, reagent~, reagent makeup . : . -10 or medium makeup to the ~econd stage. Once again, the treatment medium may either be h~gh ~olubility fluids, oxidizing agents or reducing agents. After the two stage treatment in the scrubber, the fluid iB greatly purified and then is discharged through a blower Z61. The fir~t stage i8 separated from the second stage in any conventional manner 15 and may contain eliminator plates 262 whlch remove liqu~d dropIets and mist and thus prevent the liquid or treating medium in the first ~f ~ stage fxom entering the second ~stage.
A conventlonal washer may be utilized in lieu of a scrubber.
~, ~ ~ore specifically, it consists of three element8. Spray nozzles, scrubber `, 20 plates and eliminator plates. The nozzles are placed in a bank across ~; the path of air , ,, : ~

72- ;~

:

': ' :' and th~ water is forced throu~h theln by a pump and :;s dis-charyed in a Eine spray or mist pre~er~bly in ~he di~ection of the air flow. Counter-flow or cross-flow s~rays may also be used. In some cases- two or three banks of noz~les are used. The air is drawn through the washer by the fan and is thus brought into intimate contact with the water and some of the dirt and soluble gases and particulate material are re-moved. The real cleansing, however, is done by the scrubber plates which are designed to change the direction of flow so that the dirt will be thrown out of the air by its momentum and by the rubbing of the air over the wet surface. The plates are kept flooded either by the spray nozzles or by a separate row of nozzles placed above them. Following the scrubber plates is a series of eliminator plates whose function is to remove the entrained water from the air. The lower part of the washer constitutes a tank into which the water falls and from which it is taken by the circulating pump. A float valye admi~s fresh water as required to replace that evaporated. Provision may be made also to waste a portion of the sump tank volume through a waste line to effect discharge from the system.
Proper provision must be made in an air washer to prevent trouble from the large quantities of dirt which ar~
washed from the air and deposited in the tank. This is one function of the .~.............................. ~.~
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waste line. A ~creen of a~1ple area is also nece~sary on the suction line to the pump to prevent the dirt from being carried into the circu-lating systen~ and in some ca~es ~pecial device~ may be neces~ary to enable the spray no~zles to be cleaned periodically by flu~hing. The accurnulated dirt must be removed from the tank at frequent intervals.
In a ventilating system where the outside temperature falls below the freezing point, it is necessary to protect the air washer from freeæing;
either by incorporating a tempering heater ahead of it in the air stream or by utilizing an anti-freeze solution in the spraya themselves. The air ;:

washer i9 fairly effective in clean~ing the air of dus,t but has two other very important functions. It can be used as a humidifier or as a .
'~, dehumidifier and cooler and as ~uch i~ valuable in air conditioning. In the case of dehumidification it is apparent that a refrigeration element is required and in thi~ event the spray liquid may very well be an anti~
, lS freeze .olution having preferential ~oiubility for the contaminant gases ~, which are of primary concern. ~ ' Whether a cross flow scrubber or a washer type scrubber i9 ~, utilized, an alternative embodiment is to use packing such as that set ",~; forth above, or the specialized packing described which include pall rings Berl saddles, etc. wherein the hydraullc radius of the external and internal flow channels are substantially the same. Such a provision is more ',;
~; cl~arly set forth in my exi-ting U.S. Patent No. 3, 730, 881, issued May 1, ; ~ :
197~, which is hereby fully incorporated with r~pect to the hydraulic radius of the internal and extern~l diameters. ~ ,, "~";'" 25 :
;.

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~ JI~crl th~ Ll~licl to h~ ri~icc~ contclmin~ted with ozone d5 froln ~ was~e or S~ClcJe ~reatmellt plant, the ozone concentration must be reduccd so that less th~n l/lO parts per million p~rts of c~as obtaine~ Erorn the scrubber is ozone since more than this concentration of ozone tends to be toxic.
The above described scrubber containing the packed bed having the characteristic hydraulic radii described has been found very effective in purifyiny, either by solubility or through a chemical reaction to or below the critical limit, 0.1 ppm O3 in fluid. -The scrubber fluid is generally different in eachstage of the scrubber to effect maximum purification. Although the scrubber may be utilized to remove or purify ozone as described, in general it can apply to the purification o any gas which is to be treated by a liquid in a fIuid phase type - operation. Hence, examples of other types of gases include ammonia, chlorine, hydrogen sulfide, sul~ur dioxide, and the like. Depending upon the nature of the gas to be removed, it may first be treated with a soluble fluid, an oxidizing agent, or a reducing agent. Specific examples of soluble ~luids or absorbing agents which may be generally used include liquid acids having 1 to 6 carbon atoms such as acetic acid, propionic acid, aliphatic alcohols having from 1 to 8 carbon atoms such as isopropyl, butyl, amyl and the like, glycol mixtures having from 2 to 10 carbon atoms such as propylene glycol, anhydrides ` havlng from 4 to 12carbo~ ~toms such as acetic anhydride and propionic anhydride~ carbon tetrachloride and Fr~ons which are llquid at the operating temperature of the scrubber. ;~

'.:

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The oxidizing agent~ generally can include any oxidizing agent such as ~ulfuric acid, ethylene oxide, pota~sium permanganate, ~olutions of chlorine or chlorine dioxide, ozone and air or ozone and oxygen, nitric acid, various metal dichromates, potassium perchlorate, S hydrogen peroxide, hydrogen peroxide in water, sodium nitrite, and the like. Of course, oxidizing agentY with respect to the component of the gas to be treated are well known to those skillecl in the art. Ethylene oxide is desirable for sterilization as well as with inert diluent gases (e. g. carbon dioxide, and nitrogen) to suppress explosion hazard~.
Conæidering now the reducing agents, again a wide ~ange of reducmg compoDds may be utilized in the general purification of a gas or more particularl~r a component of a gas phase. Specific reducing agents in-clude sulfur dioxide, a metal metabisulphite such as sodium metabisul-phite, Fesium compounds, and the like. Once again, numerous compounùs which~act as reducing agents with respect to the deslred component o~
the gas to be treated are well known to those skilled in the art. Pre~
ferred reducing compounds for the purification of ozone include sulfur dioxide and sodium metabisulphite.
, Concerning the removal of ozone, pxeferably the first stage of the 9crubber con~ains an absorbing agent and since ozone tend~ to be an .:
oxidizing agent, the second stage of the scrubber is ~preferably `
a reducing~ agent. Usually ozone would :

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:

.~.. '' '. ' ' . .. , ... . . ' ' ~ elimirl~t~d :in ~he Çirst sta~c. Thcn the sccond stage could utilize chlor~nated efflu~nt or a v~ry dilute chlorine 501u-tion which is .itself deodoriz~ncJ ~lowever, the initial stage may contain a reducin~ a~ellt as a treating fluid followed by the second stage containing a solublc fluid compound a~ a treating fluid. Of course, many variations can exist. Pre-ferred fluids for ozone include acetic acid, acetic anhydride, propionic acid, propionic anhydride, carbon tetrachloride, and hydrogen perox.ide in water.
10 It should be apparent that in the use and purifica-tion of any toxic gases such as ozone in air, chlorine in air or the like, safety interlocks are to be provided throughout the entire system to prevent dangers or harmful effects upon human beings from ozone or chlorine exposure in the purifica- :
tion and operation areas. Moreover, the location of the ini- ::
tial injection of the toxic gas into the treatment process is - preferably remotely located from the scrubber operation for safety purposes as well as being necessary for efficient in- ~
jection mixing and for adequate contact. . :
FLUID-FLUID TREATMENT .
According to the concepts of the present invention, a fluid but desirably a gas can also be treated or purified by treatment with fluid under conditions of high turbulence, that is, a Reynolas numbe~ of at least 3,000, to ensure ade-quate mixing or momentum ................. ~................ ~. .
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_77_ ' transfer. In general, a high turbulent purification treatment may per-tain to generally any type of gas although it is particularly ~uited in the purification of ozone as utili7.ed in the treatrnent of wa~te treatment facilities as well as sulfur dioxide.
Referring to Fig. 17, purification or tr~atment of a gas may be carried out in a flow conduit, preferably circular, as in a pipe line, generally indicated by the n~neral 301. The gas i~ admitted to the flow channel as indicated by the arrow and is conveyed throu~h the channel and exhausted. It i8 highly desirable that the Reynold~ number be in excess of 3, 000 to ensure turbul0nce condition throughout. PreferablyJ
to ensure that a reproducible velocity profile is maintained when be-ginning the treatment, the grid 304 exists to produce to suppress and ;~ reduce any veIocity gradients within the incoming gas. Typically, the ~-grid may be made of wire, plastic or the like and may be a coarse ~;;' 15 screen. For exampleJ it may merely be a screen grid with members on approximately one-inch centers of coarse wires having a diameter of approximately 1/16 of an inch. Of course, the size of the grid and wires may vary. The important factor is that à grid be utilized whlch ensures ~` the reduction of any velocity gradient~. These gradients are likely to be `~ 20 iound in disoharge sections of Lans, blowers, and fittmgs such as elbows.
Located downstream of grid 304 is a high turbulence causing de-vice such as a flat plate orifice indicated by the numeral , ~ :

.
. ~

; : . , ~ . ., . ~ .
, . . . .. . . . . , . .: . . . . .

306 and dcscr il~d }l~r~in. G~n~:rall~ e Lurbul~nce causing de~icc c~n ~ located at ~n ~lbow, union, tee or the like as previously noted. Preferably, t~le tr~ating fluid is injected into the vicinity of the orifice so that rapid and thorou~h mixing quic~ly takes place. Desirably, this can be accom-plished through a nozzle 30~ which extends into the central portion of the flat plate orifice or turbulence causing device at slightly downstream as in the vena contracta caused by the orifice. Generally, the orifice diameter ranges from about 0.7 to about 0.9 o~ the conduit diameter. A minimum ratio o 0.5 may be used if high pressure drops can be accommodated.
The location of the vena contracta is usually about 0.~5 to 0.5 conduit diameters downstream from the orifice plate, pre~
ferably at 0.3 to 0.39 and it is at this region where the nozzle - is preferably located. To further ensure thorough and complete mixingr at least cne or a second turbulence causing device may bè located downstream such as a flat plate orifice indicated by the numeral 310. The second turbulence causing device may be identical to the first device and preferably is located downstream at least a distance of 25 to 40 conduit diameters or greater and preferably at least 40 diameters. This is to ensure that a proper length exists for adequate or thorough mixing., The second turbulence causing device further ensures thorough mixing and hence derives the maximum contact proba-bility for efficient purification of the gas. The treated or ;~
.. : .. : .
purified gas may then be handled in any conventional manner such as by extended contact possibly followed ~
`' ~` ';
~ , ,' ~, .

-79 - . .
' s by exhausting to the atmosphere, by recirculation, or by the addition to a proce~s or the like.
Although the nozzle may generally be a thin pipe or tube, a preferred no~zle is shown in Fig. 19 generally indicated by the numeral 350. Noz~le or distributor 350 generally has a first portion having an average thickness indicated by the numeral 352. The diameter of the no~zle in a second portion proportionally increase3 until a very thin annulus 353 exists at the tip generally indicated by the arrow 354 of the distributor. The slope o the tapered portion o the distributor iB genera-lly less than 7 and preferably about 2 to about 3. A desirable thick-nexx of the annulus at the tip of the distributor is about 0. Ql inches. The .,, ~ . :
~ ; diameter, as indicated, generally increases at proportional rate to ~ ~
~ .
;~ ~ accomodate pressure drop of a fluid such as a ga~ and moreover to en- ~
. . , ~
sure good strength and rigidity of the distributor portion. Such a dis-tributor also tends to reduce the flow of the gas.~ Due to the provision .. . .
`~ of a very thin annulus at the tip of the no zle, the injected fluid such as ~;,. . .
:~' à gas is in very close vicinity to the conduit fluid and thereby tends to reduce any eddies as normally encountered with thick walled nozzles.
~,. . . .
~Morecver, additional shearing action is encountered due to the lack of ~ ~
. ............. .
eddies and thus promotes efficient and thorough ~nixing of the iluected fluid aa in the vena contracta region of a turbulence causing device ~uch às a flat plate orifice.
. ~ :

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8 0 -~ . ..
: ~ :

~: : :

3 s~ s In general, the high turbulence purification or treatment sy~tem may be applied to any type of fluid and treated with a sufficient amount of a second fluid to effect purification. Purification or treatment may be obtained by ab~orption or high solubility fluid~, chemical reaction, or the like and involve detoxification, deodorization, and the like. Additionally, the fluids may either be liquid-liquid, liquid-ga~, gas-liquid, or gas-gas.
The high turbulence purification or treatment sy~tem is of particular significance with respect to waste or sewage treatment ~; ~ 10 facilitie~ wherein noxiou~ or toxic: gases are encountered such as ozone, chlorine, hydrogen sulfide, various organic odors, ammonia and the like.
Thu~, after sterlization or deodorization, ~hould the fluid to be treated ~comprise ozone in oxygen or~ozone in air, the treat~ng 1uid may be an oxidizing agent, a reducing agent, or an absorbing or high solubility ~ fluid agent, as set forth above with respect to their utilisation in a i ~ ~ cross flow scrubber or washer. Thus, an ab~orbant compound ~uch as ~;
prop~onic ~acid could be added through nozzle 308 and emitted in the vena contracta portion down~tream from a first flat plate orifice device with further turbulence or mixing occurring at least Z5 or more flow conduit ~ dia}neters downstream as caused by a second flat plate orifice 310.
Similarly, as will be apparent to one skilled in the art, other compound~
; may be added to treat the ozonF through nozzle 308. ID a similar manner, sulfur~ dloxide may also be purified. Thus, treating fluid would be u~ed in the scrubber.
2~5~

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I'he invention will be better understood by reference to the following tables which set forth the minimum flow rate required for turbulence flow condition~ or thorough r.nixing, Table I, for a fluid-fluid system wherein the larger length according to either 40 second~
S contact time or a tran~istor length of 40 diameters i8 UtiliD~ed and ~imilarly in Table II for a gas-liquid system wherein turbulence cau~ing devices RUCh as a flat plate orifice is utilized. :

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-Tabl~ No. III scts forth dat~ showing the execellen-t mixing obtained when a turhulence causincJ device is utilized in a conduit of ~ fluid-fluid system. In order to determine the extent of mixing, five samples were taken at 30 conduit diameters downstream of the location in the fluid-fluid system where water vapor (gas~ was injected into air ~gas) in the vena contracta portion of a Elat plate orifice. The first location being at a radius wherein the area of the succeeding circle or annulus was equal to onP quarter of the total area. The ori~
~ice ratio with respect to the conduit diameter was 0.75. The following data was obtained.
_ABLE III

Location, R Test/R
Total 0 -.354 .61 .788 .932 DBT, C - 18.2 18.2 18.2 18.2 18.2 -WBT, C 15.8 15.8 15.9 15.9 15.9 Grains llb~ 7~. 72. 71.1 71.1 71.1 Comp, ppm 10,286. 10,286. 10,157. 10,157. 10,157.
As readily apparent from the above data, very, very small differences in concentration were obtained at various ~ ;
locations along a radi~s. Additionally, the concentration variation was generally 1~ less than the concentration average.
This table thus conclusively establishes that excellen~ mixing ~-is obtained even after a transition length of 30 diameters. This , ~

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is in comparison with aL~plicant's E)reEerred minimum transition length of 40 diameters which llecessarily would give better mixing. of course, applicant~s inv~ntion ~l~o relates to the incorporation of additional ~ownstream turbulence causing devices to ensure -thorough mlxing throughout the syste~. More-over, it establishes that a flat plate orifice having an ori-fice ratio of 0.75 based upon the conduit diameter establishes - good turbulence mixing conditions.
As should be apparen-t to one skilled in the art, many ~ -different types of fluids such as gases may be tréated. More-o-~er, a singular advantage of the in line reactor or flow con~
duit for generating chemical reactions involving gas-liquid systems is the amenability to ~ariation in pressure and~or temperature in the pipe line reactor in comparison with that ~ ' which is available in reaction kettles, packed beds or the like.
Illustrative o~ inaustrial processes whlch are of importance and which involve gas liquid reactions are the various example~
set forth in "Examples of Processes of Industrial Importance where Gas A~sorption is Accompanied by Chemical Reaction", Gas~
Liquid Reactions, P. V. Danckwerts, F.R.S., McGraw-Hill Ser~es in Chemical E~gineering, 1970 which~-is ~ePe~y fully ~ i incorpQr~$e~ by r~rence wi~h-respect~to ~ v~rious~ eactions as well as the reEerences cited therein. An abstract of this article which sets forth illustrative examples is as follows: -- , : ~

. , -86~

r~
_ 1~ 4S
1. C02, COS, ll2S, C12 (i) Absorption of CO2 and C12 in aqueous solutions of barium sulphide for the manufacture of BaCO3 and BaC12, respectively; see Gupta, R.K. and M.M. Sharma: Ind. Chem. Engr. 9 (1967) Trans.

- .
tii) Absorption of CO2 in aqueous suspensions of line for the manufacture of precipitated CaCO3;
see Morris, R.H. and E.T. Woodburn: South Afri-can Chem. Processing (June-July 1967) CP 88.
(iii) Absorption of CO2 in aqueous suspensions of MgO
for the manufacture of basic MgCO3; see (a) Shrevej R.~.: Chemical Process Industries, 3rd Ed., McGraw-Hillr 1967.
- (b) Faith, W.L., D.B. Keyes, and R.L. Clark, Industrial Chemicals, 1965, 3rd ed.,;John Wiley and Sons, Inc., New York.
(iv) Absorption of CO2 in aqueous suspensions of CaS
see Chem. Engng. 75 ~1968) 9~
20 (v)~ ~Absorption of CO2 in aqueous solutions of sodium silicate; see Dalma~tskya, E.J.: J. Appl. Chem. ; :
USSR 40 ~1967)`464 ~Engl. Trans.l (vij Absorption of CO2 in aqueous solutions of Na2S. "
(vii~ Absorption of CO2 in aqueous solutions of po~
tassium carbonate of amines, for removal of C02 from synthesis gas; see Danckwerts, P.V.~and M.M. Sharma: Chem. Engr. (October 1966) CE 244 Isee~10~

:: . ' . ' :

- .

' ~ :

~: ~
"

.. . ~. : ... . .. . . . .

2. ~S2 Abso~ption in aqueous amine ~olutions Eor the manu-facture of dithiocarbamates; see Kothari, P.J. and M.M. Sharma:
Chem. Engng. Sci. 21 (1966) 391.

(i) Absorption of 2 in aqueous solutions of CuCl for conversion to CuC12 and copper oxychloride;
see Jhaveri, A.S. and M.M. Sharma: ~hem. Engny.
Sci. 22 (1967) 1 (see 10-3) - 10 (ii) Oxidation of Na2SO3 by air or oxygen; used for establishing the charactertistics of absorption equipment (see 10-3) (iii) Air oxidation of acetaldehyde, butyraldehyde, etc., for the production of corresponding acids and acid anhydrides; see (a) Marshall Sittig: Oxgani¢~Chemical Process Encyclopedia, Noyes Develop. ~orp., U.S.A., 967.
~b~ ~rbaski, T., and I. Brihta: Arhiv. Kem.
24 (1952) 111; C.A. 49 (1952) 163.
(c) Kostyck, N.G., Loov, S.V., Falkovski, V.B., ;
Starkov, A.V., and N.M. Levina: Zh. Prikl.
Khim. 35 (1962) 2021, J. ~ppl. Chem. USSR
35 (1962) 1939 (Engl. Trans~
(iv~ Oxidation of cyclohexane to adipic acid; see Steeman, J.W.M., S. Kaasemaker, and P.J.
Hoftijzer; 3rd European Symp. Chem. Engng. Chem.
.
Reaction Engng. Oxford, Pergamon Press, 1961, pp. 72-80.

: .
.. . . : .
; -88~

, 4~
~v) ~ir ox.ida~.ion of curn~ne to ~umene hydroperoxide ~pr~c~lrsor for pll~nol); see (a) Low, D.l.R., Canad. J. Chern. ~ngng. ~S
(19~7) 166. :~
~b) Maminov, O.V. et al.; Khim~.ya i Tkh. Topliv., Masel (1967) (12), a (Brit. Ch~m. Eng. :.
Abstract 1968 Mayl p. 712) (vi) Air oxidation.of toluene to benzoic acid; see Faith, E.L., D.E. Keyes, and R.L. Clark: .
Industrial.Chemicals, 3rd Ed., 1965, John Wiley . ~ ;
. and Sons Inc, New York. :~
4- C12 .
, A. Addition Chlorination (i) Reaction between C12 and C2H5 in C2H4C12 me~ium; see Balasubramanian, S.N., D.N. ;~
Rlhani, and L.K. Doraiswamy; Ind. Engng. .
Chem. (Fundamentals) 4 (1965j 184.
(ii) Reaction between C12 and C3H~ in C3H6C12 .
~ medium; see Goldst~ein,~R.F.~, Petroleum ~ 20 Chemica~sIndustries, 2nd Ed., 1958, London~ ~.
E. & F.N. Spon Limited.
~; ~ (iii) Reaction between C12~and C2~2 to tetra-chloroethane; see~Marshall Stittig;
~ ~ . Organic Chemical Process Encyclopedia, - Noyes Develop. Corp., U.S.A., 1967. .
~ iv) Reaction between C12 and trichIoroethylene `; ~
: : : to give pentachloroethane ~precursor of : `
;~ ~ perchloroethylene); see Goldstein, R.F.; :.
Petroleum~Chemicals Industries, 2nd~Rd., 19$8l London, E. ~ F.N. 5pon Limited.

89~

. .
'. ' ~ ` ~ `~`

. S~b~ ution C~hlc)r~rl~tion (i) Cillor.ination of a var.iety of or(Janic com-pounds such as benz~ne, toluene (side chain ~s well as nuclear), phenols, e~c. See, e.g.
~la~Ykins, P.S~: Trans. Xnstn. Chem. Engrs.
43 (1965) T.287. ~.
C. Miscellaneous , (i) Reaction of C12 with sulfur or sulfur mono~
chloride to give sulfur monochloride and ~-~
iO sul~ur dichlorid~
(ii) Reaction of C12 with S02 to give su~furyl chlo.ride; see Kirk and Othmer: ~ncyclopedia of Chemical Technology, Vol. 13, 2nd Ed., 1967, New York, Interscience Publishers, pp.
319, 403. . :~
.
~iii) Reaction of C12 with PC13 to give PC15;
- . see I~em., Vol. 10 (p. 477) ..
.- (iv) ~eaction of C12 with FeC12 to give FeC13; :
see Gilliland, B.R., R.F. B~addourr and P.L,T.
Brian: A.K. Chem. E.J~ 4 (I958) 223 (see 10~2)- ;
. 5. SO
Absorp~ion of SO3 in ~I2S04 for ~he manufacture o Oleum; see Duecker, W.W. and J.R. West: The manufackure of ::
sulfuric acid, ~einhold Publishing Corp., New York, 1959.
6. NO2 Absorption in water ~or the production of HNO3; see (a) Andrew~, S~.P.S. and D. Hanson: Chem. Engng.~Sci. 14 (1961) 105; (b) Xramers, H., M.P.P. Blind, and E. Snoeck; Chem. m :
::
:~ Engng. Sci. 14 (1961) 115.
' L~
7. (-`OCl2 ~bsorption of COC12 in a]kalille solutions; see MonacJue, ~.H. and R.I,. Pi~3ford: ~.I. Chem. E.J. 6 (1960) ~94.
8. H~
Hydrogena-tion of a variety of unsatur~ted organic compounds in the presence of catalysts; see (a) Satterfield, C.N. and T.K. SherwoGd: The Role of Diffusion in Catalysis, Addison Wesley, 1963~
~b) DeBoer, J.H. et al.: The Mechanism of Hetero-geneous Catalysis, Amsterdam, Elsevier Publishing Co.i 1960.

9. Deu-terium Ammonia-hydrogen process for deuterium separation, see (a) Bourke, P.J. and J.C. Lee: Trans. Instn~ Chem~
Engrs. 39 fl961) 280.
(b) Bourke, P.~. and D. Pepper: Trans. Instn. Chem.
:
Engrs. 41 (1963) 40. ~ ~
, ~

10. Olefins (i) Absorption of isobutylene in aqueous solutions of H2SO4 for the manufacture of tertiary butanol and for poly-merization to di-iso and tri-isobutylene; see Gehlwat, J.K.
.
and M.M. Sharma; Chem. EngngO Sci. 23 (1968) 738.
(ii) Absorption of isobutylene in phenols and sub-stituted phenols in the presence of H2SO4 as a catalyst ~or the manufacture of the corresponding alkylated products;
. . .

.

' ' .
,~ ' ', --gl-- . .
'~

.
, ~6)~
(~) D~Jon~, J.I.: ~ec . Tr~v . Chern. 83 ~l969~ 469.
~b) ~itn~y, W~: ~nd. ~n~. Chem. 35 (1943) 264.
(c) Jelinck, J.: Chem. Prulnysl 9 (1959) 398; C.A.
54 (1960) ~696.
(iii) Absorption oE butadiene in cuprous ammonium complexes; see Morrell et al., Trans. A.I. Chem~ E. 42 (1946) 473.
(iv) Absorption o~ butenes in sulfuric acid for con-version to secondary butanol; see Rustanov, K.R. and N.M. -Chirkov: Zhur. Fiz. Khim. 30 (1956) 261; C.A. 50 (1956) 11081.
(v) Absorption of acetylene in aqueous CuCl solutions to convert it to vinyl acetylene; see Marshall Sittig:~ Organic Chemical Process Encyclopedia, Noyes Develp. Corp., U.S.A. 1967. ;~
(vi) Absorption of ethylene in benzene to produce ethyl benzene using AlC13 catalyst; see Marshall Sittig~
Organic Chemical Process Encyclopedia, Noyes Develop. Corp., U.S.A. 1967.
(Vli) Absorption of acetylene in arsenic~trichloride dissolved in C2H~C14 for the manufacture of chlorovinyldich}oro-arsine; see Whitt, F.R.: BritO Chem. Eng. 12 (1967) 554.

: ~ . . .. . .

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^ -92 ,:

, ! .~

:!.`.,: :' : :. . . . ' ' ' . ' ' . . :' . : . . : `

~l t~
(viii) Absorp~ion o~ et:hylerle ill sulfor mono- or dichloride dissol~ed in benzylchloride for the manu~acture of dichlorodiethysulfi~e; see W~litt, F.R.: Brit. Chem. Eng. i2 (1967~ 55~. (Some other exarnples are also given in this paper~.

11. S2 -(i~ Absorption of So2 in aqueous solutions of NaHSO3and Na2SO3 in the presence of zinc dust to manufacture dithio-nite; see Suzuki, E., E.O. Shima, and S. Yagi: ~ogyo Kagaku Zasshi 69 ~1966) 1841.
(ii) Reduction of SO2 in SO3 = /E~SO3 - buffer by NaHg amalgam.
(iii) Absorption of SO2 in aqueous solutions of NaNO2 and zinc dust for the manufacture of hydroxylamine.

12. HCl and ~Br .
(i) Absorption of HCl and HBr in higher alcohols for : the manufacture of the corresponding alkyl halide (e.g. lau~yl ~;
alcohol to lauryl chloride or bromide); see Ringsley, H.E~
and H~ Bliss, Ind. Eng. Chem. 44 (1952) 2479.
~ii) Addition of HBr to alpha-olefins for the manu-~acture o~ alkyl bromide (with terminal bromine atom), e~g.methyl undecylenate reacting with HBr.
(iii) Addition of HC1 to vinyl acetylene for the manufacture of chloroprene.

..

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.
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'' :' . , ' ~' ' :.
- , ~ .

_93_ :. .

In lieu of a conduit having multiple turbulence causing devices therein, additional embodiments include abruptly changing the diameter of a pipe or flow conduit as well as the provision of a mani-fold takeoff. Either of the~e will help to reduce the total system length otherwise required for thorough mixing and hence greatly reduce the physical Ypace required. Considering the abrupt diameter change, a turbulence causing device such as a flat plate orifice ia preferably located at the end of a constant diameter pipe which is connected to a constant diameter pipe or flow channel of a larger diameter. For ex-ample, a 4 foot pipe with a flat plate orifice at the end thereof of diameter ratio sufficient to remove the boundary layer fully may be connected to a 7 or S foot diameter pipe. Such an orifice at an abrupt change in diameter ensures thorough mixing and hence auppre~sion of any ~adial concentration gradients. In such a situation, any subsequent downstream `
turbulence causing device being at a diatance of at least 40 pipe or conduit diameters.
Considering the manifold arrangement, it consists oE a pipe or flow conduit which is abruptly cbnverted into ~everal pipes of , smaller diameter wlth a larger overall total conduit flow area if it is desired to maintain the same pressure drop per ioot as to the large conduit. For example, a single 4 foot diameter pipe may be abruptly transitioned by manifolding into 24 one foot diameter pipes.
The first turbulence causing device such as a flat platel-_ 94.

. : . . . , - , . . -.. ... . . . . . . . . .

orifice i5 preferably loca~ccl in each manifold rela-tively near the conversion from a sir~gle pip~ .into the multiple pipes According to such an embodiment, the t~ansit.ion length may be reduced from 40 diameters, i.e. 40 x 4 feet to 40 x 1 ~oot, a reduction o~ 120 feet~ Of course, other turhulence causing devices may be located downstream as before.
; Re~ardless of ~ype of alternate embodiment in point, .. the admission of a treating fluid may be carried out in accor-dance with the above set forth disclosure.
In the conveying of fluia from one area of the system such as a treating portion to another area, the diameter of the flow channels may be changed, as desired~` For gradual transi-tions to decelerate subsonic flow, the diffuser transition ~`~
should not exceed a slope of a~proximately 7 to ensure that boundary.layer separa-tion is suppxessed. This slope is not :
- critical for transition nozzles which abcelerate subsonic flow.
. Pre~erably, following a ~luid phase treatment station, .
including downstream mixing as through second or third turbu~
lence causing devices, a contact chamber may be provided. The .
purpose of such a chamber is to extend the detention time of . ~ : `
the treated fluid after ideal mixing has been developed.

OZONE PRODUCTION . ::
According to the concepts of the present in~entLon, an .

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~95~

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improved pLOCeSS for tl~e production of ozone may be utilized.
In general, an ozon~tor requires a feed of ~yyen containing gas, a voltage yotential and a minimum amount of pressure.
Upon application of the voltage, oxygen in the feed gas which is under pressure is partially converted to ozone. It is known that the production of ozone can be maximized at high gas feed rates. These yield relativel~ low ozone in gas concentrations.
It is also known that ozone can be produced by varying the feed ~ ~ ' rate of oxygen and the voltage. It has been found that this ~, ' can be done in such a way so as to maximize the ozone concentra~
tion which may be dissolved in a t~eated fluid. To do this requires a departure from standard teaching. A sacrifice is , `~ ' ' required in the electrical ener,gy consumption in kilowatt hours per pound of ozone produced. Specifically, the feed or amount ' of oxygen containing gas fed into the ozonator is reduced to the minimum required amount and the voltage is increased to "' the maximum amaunt possible with the particular unit. The ef~ ' ,'`~ , , fect is to obtain less than maximum or rated ozone production. ,~' However, this sacrifice in ozone production is more ';' ' 20 than ofset by a gain in efficiency of gas liquid injection and mixing derivable in the following step. This mode of opera- ' ' tion of an ozonator enhances ozonation by allowing higher ozone ; '' concentrations in a treated fluid within the limit of the satu- ,~
ration quantity of any component of the carrier gas in the ;~
.~

: , , . ' ~:

.
-96- ~
' .

s treated fluid~ E~or ex.lmple, on ~ir feed, an ozone soncentra-tion of 2.5~ is possible. From air, the nitrogen solubility in water is 18 ppm. T~le air fe~d is proportioned to provide this quantity o~ nitrogen. The quantity would be 2~.5 ppm of air, of which 2.5% would be ozone. The 2 and 03 fed would stabilize at 4.5 ppm unless oxidation reactions deplete the ozone. The corresponding ozone concentration in the treated fluid would be 0.56 ppm. Ozone-fluid solutions are bacterici-dal and viricidal at ozone concen~rations of 0.5 ppm or greater.
Thus, this technique achieves disinfection without entailing an inherent loss of ozone in gas blown through the fluid sys-tem owing to gas-fluid saturation in the treated fluid. It should be recognizad that gas ~eeds at rates above -these cor- -~
responding to saturation of any gas component in the fluid will and must be followed by gas blow through. In blow through, ozone and non-saturated components of gas will be lost. ~t follows that the operating principle is to feed gas or gas mixtures at the lowest possible rate, preferably at component gas saturation limits or less. Potential loss of ozone from ~0 inefficient gas-fluid mixîng is many times greater than the loss in ozone productive capacity induced by ozonator opera~ion at maximum practical ozone in oxygen containing gas concentra-~ ,tions. Recognizing this, it follows that ozonator improve-ments focused on suskaining hwh/pound of ozone produced at maximum possible ozone concentrations in oxygen containing gas ~ .
~; ' . ' ' .-_97_ , : . ., . .. . ~ ,:. ..

are most de~sir~ble. The o~or~e, o~ co~lrse, can be used in any subsequcnt process such ~s in sewage or waste treatrnent plants herelnabove described as well as or any other conventional uses. The important factor is that the process only requires the smallest possible amount oE oxygen as feed so that upon ~
the application of the voltage, a maximum concentration and ~;
amount of ozone is produced. ~ ;
OZONATOR CH~RACTERISTICS
Production Rate. The production rate of an ozonator .
depends primarily upon the applied energy. Operatin~ controls usually provide for a broad range of input gas flow. The gas must contain oxygen. An increase in oxygen concentration to twice that for air approximatel~ doubles the ozonator produc-tion rate. For a 100~ oxygen feed, little increase in produc- ~
tion-rate is observed above that for oxygen-enriched air at 40~ ;
oxygen concentration.
As the gas feed rate to an ozonator increases, the ozone concentration in the ozonated output flow decreases~ The decrease is almost exactly inversely proportional to the ~
inpu-t gas feed rate. Thus, for a gas feed rate Wg in pounds - pex minute and an ozone concentxation, C, in parts per million, `
.
in the output gas, the ozonator production rate WO in pounds per minute is almost a constant. This is shown in the Fig. 30.
Note there that the volumetric feed rate is used instead of the weight feed rate. However, the relationship on log-log coordinates is almost linear. The relationship, ', ' Wg C = ~o ' ~;
as defined before, would plot as a straight line. The dotted line illustrates this relationship.

~ .
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~.. . . . . .

The ill~lstr~tion also 5~10WS how a reduction in energy supplied to the o~,on~or can reduce the production rate of ozone. Practicably, this is the only control on ozone output except for a change in oxygen enrlchment of the ozonator feed gas.
Fig. 36 also shows energy requirements for ozonation only. Additional ener,gy is required to dry and compress the ozonator feed gas. From preceaing discussion, it is apparent ` that maximum ozone production occurs near the mid-range of any plot. Hvwever, ozone production at the lowest range o~ any plot is not materially less than that for the maximum condition.
This lowest range of gas feed rate corresponds to the maximum ,~' ozone concentration. Elsewhere in this specification, it has been indicated that gas-lqiuid mixing efficiency is potentially greatest at the highest ozonator output ozone concentration - ~ . .
achievable. ~Thus, overall ozone-applied efficiency is deri- ~ , vable by ozonator operation at minimum gas flow feed rates~
: ~
These compromise ozone production slightly. The compromise is more than compensated for by the improved injection-mixing , 20 efficiency. ' ''~` ' Further, under this recommended mode of operation, ,"
the total energy re~uired per pound of ozone generated and applied within the overall syst,em is reduced. This is so owing to the marked reauction in feed gas drying and compres sing energy which is necessary at minimized ozonator gas,feed rates. One factor which contributes to this fortuitous cir-cumstance is the moderate effect of nitrogen in ozonator ~eed gas~on p~oduction rate. To about 60% nitrogen in oxygen of ' the feed gas, nitrogen does not materially degrade the ozone '~
production rate.

_ .',-' :..:

:: ' ~ t is use~ul to consider -the comparative performance of an o~onator on oxy~ell enriched ~ir Eeed a~ the recommended low gas feed rate with that for the normal flow rate. The comparative ozone concentrations are 55. mg/l and 25. mg/l.
These correspond to ozone concentrations in the ozonated gas output of 4.6% and 2.1~ resp~ctively.
This comparison appears in the table which ollows.
There, the production rate column shows that ozone output is slightly greater at the relatively low ozone concentration of 2.1%~ 25. mg/l. This occurs at the highest feed gas rate.
The specific energy column reveals that this high gas rate corresponds to high energy penalties ~or drying and compressing the ozonator eed gas.
Compare these condi~ions with those for production a~ 55. mg/l, or 4.6~ ozone concentration in the ozonator output -There, the lowest ozonator feed gas rates prevail. At 200 watts, the ozone production rate is 14.6 g/h at low gas rates.
It is 17.3 at the high gas feed rates. This is a reduction of about 16%. However, the specific energy for the low gas rate 20 i5 8.5 kwh/lb. The high gas rate exhibits a specific energy of 11.3 kwh/lb. The reduction in specific energy is 25%. It is logical therefore to sacrifice 16~ in rated production for a 25% saving in energy. ;~
In addition to this economic ad~antage, the high ozone concentration enables markedly increased ozone input to the treated fluid. Thus, the overall system efficiency is increased greatly while the energy requirement is reduced 25%.

Finally, the oxygen-enriched air feed gas contributes : ., ~ :.

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- furtheL aclv~ntclgos. o.~yg~ nrichmcnt at 40~ oxygen, 60g ni-trogen almost doubles ozona~or production compared to produc-tion on ~ir.
Less oxygen enrichlnent is proportionately beneficial.
One particular enrichment is of interest. In this specification, it has been noted that air-saturated water exhibits a dissolved gas distribution of one part oxygen to two parts nitrogen. This :
has shifted from the input gas distribution, in air, of one part oxygen to four parts nitrogen.
- It might be expected that oxygen enrichment of air to 33% oxygen, 66~ nitrogen would be in equilibrium with the one to two ratio noted above. This is not so. ~s the oxygen con-centration in the fluid saturating gas increases so does the oxygen concentration in the dissolved gas. For this reason, -the preferred range of oxygen-enriched air feed for ozonation is from one-third to two-fifths oxygen.
~ Under these condition~ recycling of the desorbed ozonated carrier gas is possible at minimum oxygen feeds to sustain desired enrichment of feed gas. This mode of ozonator operation, i.e. low feed gas, flow, recycling, high ozone con-centration and oxygen enrichment of air feed comprises the i;
optimum overall system for generating and dissolving ozone in ~ ;~
treated fluids. These system operating conditions are optimum ~ ;
in tenms of overall cost of o~onation per unit weight of ozone dissolved in the treating fluid.
; ~ In the foregoing system~ small quantities of oxygen makeup may be required. This may be supplied from on-site ~;~
oxygen generators, from LOX storage or from gas-phase storage~

Since the equilibrium concentrations ................ ~O.... ~.~
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of dis~ol~ed gas in air-~aturated water are 33% oxygen, 66% nitrogen an alternative source of makeup feed ga~ i~ poaQible. Pre~suriæed water aturated with air. The saturated water i8 decompre~ed. Desorbed gases are recovered. These ga~es will be compri~ed of 33% oxygen and 66% nitrogen. They represent a near ideal ozonator feed gas. This feed ga3 could be enriched with oxygen, if de~ired.
A typical sy6tem for the production of ozone is shown in Fig. 37. Numeral 710 is a compres~or which feed~ the fluid, prefera-bly air through a length of piping containing turbulent producing devices to insure complete mixing ~uch as flat plate orifices ~et forth above ~'" ;' separated by at least 40 pipe diameters. The fluid is then held in a high pre s ~ure tank 7 15 which contain~ an atmos phe re rich in nitrogen .
The fluid is then fed through an expansion valve 716 which may be a hydraullc turbine generator eO recover energy in the form of electrical IS ~ or mechanical energy to a low pressure desorber 720~wh~ch:contalnR
an atmo~phere rich in nitrogen. Each tank contain~ water. Part of the . ^ water from the second or low pre~sure desorber i8 re~cycled~through a ~ -pump 72~1 and plpe 722. The air or fluld i8 then fed~vla line 723 to dryer 725 which may be ~ilica beds wherein the air is alternately fed to one ;~1 ZO~ tank and not the other. Thi~ procedure is generally preferred to drying by refrlgeration below the dew point.~ Wlth re~peet to the liquid in tank 715 and 7~20, water may be utilized as noted but generally any :
liquid having higher solubility for oxygen than nitrogen may al3o be utilized. The alr, after drying, is then fed to an o&onator as herein-above~ described via pipeline 728. ~ The fluld containing a hîgh concentra-tion of ozone is then fed to a contact tank 740 via a pipeline 73S wherein rnixing devices are contained such as flat plate orifice~. After the contact t~-nk, part o the gas or fluid i8 recycled to the dryer whereas the liquid in the contact tank ~uch a8 water may be pumped out at will.

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ROT~RY DIST~IBU'[`OR ~E~ N _NO%ZLE
FOR 'rRICI~LING FILTER , ,' In a t~ic~linq filter, the bed beneath the distributor arm should be dosed ~ith,liquid at a uniEorm 1~w over its area, expressed in ~allons per square foot per day. A usual maximum rate is 1,000 gallons pex s~uare foot per day. It is necessary for e~ficiency and economy of,operati~n that the dose rate be uniform with radius at any impressed total flow on the system.
The reason fox this is that at any impressed flow rate, the flow from the distributor must dose the trickling filter media with equal quantities of flow per square foot of surface. Since the ~;
surface of the filter goes up as the square of the radius it is ~, understandable that the f low is going to have to go up quite a .
bit at the outside edge. Unless some provision is made for channeling the flow, the tendency in an actual operating filter is to make the f~ow distribution speed dependent. This will '~
tend to unwater the central section of the arms and,to shift '~
. . s major flow towards the outer radii of the distributor arm. It '~
is particularly'a problem to insure uniform flow at low flow rates.

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Now referrincJ particul~rly to Fi~. 20 - 23 of the drawings, the dis-tri~utor arm is indicated by nu~eral 399. A
dotted line 400, as seen in Fig. 22 runs down the centerline ` of arm 399, and this represents a closure which isolates a channel allowing only half the total channel to be available for flow in the filter distribution arm for a lower portion of the section. Fig. 25 better shows the cross-sectional configu- ~, ration, and clearly indica~es the divider section 400, as well as a horizontal divider section 402 which will be discussed in further detail hereinafter. Note in Fig. 25 that the upper surface of divider 402 is at substantially the same level as the centerline 404 of the orifice opening 405 (orifice 410 not shown in Fig. 25). The orif;ce locations are present in the ;
.
maximum number for which space is available and they allow effluent to be removed from the dlstributor arm.
Now with reference to Fig. 25, the construction is provided to isolate the flow of effluent until the level builds up to the top surface of divider 402. First in considering this buildup of level, it must be assumed that flow occurs at a variable rate as it is distributed by the distributor arm.
This flow rate depends on the rotative speed of the distributor arm. A usual maximum rate is l,000-gallons per square foot per day. However, by doubling the width of the channel above the divider 402, O.... ~.~... ~.~............... ~.. ~.... ~.~. i ;
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.. . . .

what has been achicved is in effec~ allowin~J a fur~her increase in flow to occur with a rcduced change in level on the dls-charge orifice. This reduces the range in one variable. Other means that may be used to vary the distribution rate are to vary independently ~he diffusiny nozzle to improve control of thrustt speed of rotation and difEuser flow such that the dose rat~ is uniform within the radius at any impressed total flow~ ~ence, unless some provision is made Eor channeling the flow, the tendency in an actual operating filter is to make the ~low distribution speed dependent. Therefore, I have found that by blocking off the lower part of the section by divider 402, the flow at low rate is insured and it reduces the effect of in-creased flow at high rates by accommodating it with a smaller ~;
change head.
An additional feature of the distributor arm 339which is interesting is that its diffusing orifices indicated generally by numerals 410 and shown in Fi~. 24 are positioned at various locations along the length of the distribution arm in Figs. 22 and 23, are variable in elevation, that is, by rotation, the flow passage can be modified by rotating the orifice. In this way, depending on orifice configuration, ro-tation may be used to vary the head and flow or momentum change~
The momentum change develops thrust. This effects distri~utor speed. Speed effects the 'nead along the distributor radius.
Thus, it is important to be able -to change head, flow and momentum changes in an orifice independently, and the orifice~

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210 ~s seen in Fig. ~8 incorporate a hex nut 212 to allow the orifices to be mecllanic~lly twis-ted to vary the direction of their -thrust.
Figs. 29 and 30 represent a modified ori1ce co~-prising a 90 elbow. This may a~ain be rotated by means o~
the hex nut 212~ either using a wrench or hand pressure. It may be rotated to discharge vertically upward or downward. The head and flow would thereby be varied greatly. The change in momentum would be a function of the velocity of the li~uid, as well as the angular position of the orifice.
Again referring to Fig. 28, each nozzle 210 incorpo-rates a slot 214 milled into a circular pipe section 216 com prising the nozzle. Further, an end cap 218 has a slot 220 cut therein so that in effect two separate slots for control purposes are available. Preferably the slot 220 is elongated and circular on the ends but as it can be seen it is eccentri-cally offset from the centerline 222. Thus by rotating the ;~
slot 214 upwardly, the flow is reduced because the head is reduced. In this instance as shown in Fig. 28 you could have a lot of flow coming out the slot 220, but ncne coming out othe slot 214. Now again looking at the slot 214, if this is rotated down, then the slot 220 in the end of the cap will be rotated up so that there is no flow directly out the end oE
the cap, but all or substantially all of the flow drops down onto the filter bed from the slot 214 in the short nipple : .
section of the nozzle. Considering the desire to change independently the relative flow and the propulsive , .

~i -107-e~fort at tllc s~mc tim~, this is possible by mutual c~ang~s in ~he an~ular settings of the two rotat~ble elements, namely cap 218 and nut 212 and pipe section 216 which comprise the nozzle 210.
The rotation of the no~zle elements can ~e done manually, but most conveniently it can ~e done using an appropriate,wrench. Primarily, the idea of adjusting the angular position of the slots for flow control is to accom~
modate changes in flow which occur progressively on a plant, usually towards an increasing flow, which would occur over a long period of time, rather than daily incremental changes ;~
without effecting the radial uniformity of dose to the filter bed.
. :
' It must also be understood that the speed of the distributor arm is important in that the distributor rotates by reason of propulsive effort. As the speed changes, an ; ' effect on the pressure distribution in the distributor arm occurs. This is apparent from the ~act that the liquid surface in a rotating vessel is paraboloidal. Thus, the virtual head 20 , approaching the distal tip of the distributor is higher than ~ ' that at the center by the difference in magnitude of the paraboloidal ordinates. The general effect of the increased head towards the distal tip of the arms would be to,increase '~
the flow disproportionately in that region. This is one reason why I have determined to take the measures with respect to the nozzle slots to control the rotative speed of the dis- ~ ~
tributor, and also . . . . . ~ . . . . . . . . . . . . . . . . ~ ' - . . .

' ' ' '~ ~
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`' , , a5 the measures to control the flow ch~nnel as seen in Fi~. 2S, which was di~cussed ~bove. There~or~, this ~istributor in the en~odiment shown in these drawings will accommodate with independent means and provide the adjustment nece5sary to achieve the basic objectives of making uniform over the ran~e and radius the proper flow distribution per unit area of receiving'media below the arm.
As a ~urther result the rotatable cap 418 ~acilitates cleaning of material which may become entrained in the oriices or slots 414 and 420. It should be noted with respect to Fig. '~
24 that the nozzles 410 are actually placed in the closest pos-' sible spacing such that you can maximize the'number of slots or orifices which are inserted into an arm.
A further point that should be noted with respect to , Figs. 20 - 23 is that the nozzles appear on the upstream face ~' of the distributor'arm as well as on the downstream face, and , this is seen in Figs. 22 and 23. Tha purpose of the upstream orifices or nozzles is to enable further control over the pro-pulsive effort and the speed which is developed in the distri-' ,', ; ' butor without compromising the uniformity of flow dosage per ;
unit area oE receiving media beneath the filter.
, Another possibility with the type of distributor arm defined above is to insert instead of spray head nozzles such as shown in Fig. 28, some type of closure plug which in this way adjuststhe flow independently of the orifices. That is, by removing nozzles and placing in a suhs-titute blanking nozzle, which is a standard pipe plug, the flow can be controlled.

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~ u~ er del:ail in ~l~e constr-lction of the distr;-butor is a vent to preverlt ~he formation of a vacuum. Such vents ~30 are shown in Figs. 22 and 23.
A further feature oE the structural requirements of the arm is to have tie rods indicated yenerally by ~he numeral~-A
432 and best seen in Figs. 20 and 21 extending from various points along the length o the arms back to -the céntral support post 434 to support the arms in cantilevered fashion from the ;~
central distributing head 436. Such tie rods 432 compensate for horizontal forces which occur by reason of an acceleration or deceleration, and the structure of the arms themselves is that they function as a variable section-modulus beam rom zero radius to the radius of the distal tip so that they are suppor-ted at independent points by the rods 432 which are adjustable so that the distributor may be trimmed when it is installed to operate in a horizontal plane without a stress which would occur with a cantilevered arm. - ~ -The multiplicity of tie rods and the stress analysis of such a distributor is based on approximations concexning intermediate structures involving a continuous beam supported on three intermediate supports. It can be utilized analyti-cally at least as a first approximation as a constant section beam. Subsequen-tly the analysis needs to be refined for chec-king. It should be strongly pointed out and is clear :~rom the drawings that the section~modulus varies continuously along the length of these arms from a larger cross~sectional configu-ration near to the hub 436 to a much smaller cross-sectional configuration at the distal tip, and hence the section-modulus and the stress analysis needs to be made more sophisticated to ',', ' ;;-"'.

110- . ' ' acconunodate the VariatiOIl in section~modulus as a function of radius of the ~istributor. In other words it is a feature of the inv~ntion that the arms are tapered or decrease in cross-sectional area all the w~y along the whole length uniformlyO
The tapered configuration to the arms makes them less sensitive to changes in rotative speed of the distributor and to short term changes in distributor flow, and pronounces the effect of getting a grea~er volume flow out the nozzles the further they are away from the center of the hub because it is that area of the filter medium that needs a greater flow because a greater area is being covered the ~urther they are away from the center of the hub.
Now again referring to the cross-sectional configura-tion of the arm which is substantially rectangular as seen in Fig. 25, the divider web 400 furthermore serves as a reinforce-ment between the upper and lower flanges 401 and 403 o the distributor arm which functions as a stiffening beam web. Not~
that the web 400 is interrupted periodically with holes through , , it such as at 405. These holes 405 allow fluid to enter into the upper channel of the blocked off section as well as in the normal channel.
Now referring particularly to Fig. 26, this represents the same cross-sectional configuration of Fig. 25 except sub-stantially doubled in heighth. with the blocked off regions 440 and 442 blocked in both the upper and lower channels. The upper channel (overload flow channel) is separated from the lower channel (normal flow channel) by a horizontal divlder 443. The intention here is to have the upper section function under high conditions of plant flow ......................... ~............... ~
;:~ . - :
' .

, --111 , `~

and insure the proper distribution of flow along the radius of the distributor regardle~s of the level of flow. One must be particularly careful about how this i~ occurring in that an extren~ely high flow rate would norrnally make a trickling filter distributor rotate e~ccessively fast. High ~peed would throw the liquid out to the outside radii of the distributor making the flow distribution through the rnedia not a uniform flow per unit of surface area expo~ed. With the embodiments shown in Fig. 26, however, this di~tributor section would maintain approximately the same width or heighth ratio in the cross-section as in Fig. Z5 for ~-; 10 the norrnal distributor. In other words, the heighth and width ratio would be the sa~ne in the double channel distributor ar~n as in the single channel.
: , In order to understand how the double channel or overload flow configuration of Fig. 26 would work. reference should be rnade to :
Fig. Z7 where the numeral 435 represent~ the central column of the trickling filter with flow coming in as indicated by the arrow 450. The ' normal flow for the effluent will be directly into the normal flow channel ''1 of the distributor arm or as indicated by arrow 452. However, when the flow builds up over the weir type pipe section 4S4 overflow will occur in , the direct~on of the arrow 456, and thence down into the overload flow ; ~ ~, " ~ 20 channel of the distributor arm as clearly shown in Fig. ~7!~ The weir equation that is pertinent is Q = 3. 33 x c x H3/2 ft. The ske~ch of the ;cfs ft.
diagrarn of Fig. 27 indicates ho which is~ the weir head elevation of :
~ the weir with no flow over it. Basically the above equàtion gives the , ~ :
weir flow which would be accomodated in the upper channel when the flow ; , 25 ~ overflows the overflow weir. The flow then in the lower channel or the normal 10w channel .
` - 1 1 2 -' ' .

would then increase l~ss at ~ny l~vel of flow beyond that cut-off for the p~rticulary head ho. ~fter the h~ad ho is reached~
the overflow of the weir all would pass into the upper or over-flow channel in ciuantities or at flow rates as given by the e~uation. The heaa on the wei.r would be the ac~ual head of water level of the edge of the weir which is marked on Fig. 27 .
as hl meaning the head of the.liquid, in ~eet.
'Hence, ln summary, the flow in the rotatin,g distribu~
tor arm is governed by two things. These are the nozzles that are present and the rotative speed of the d.istributor. These are the only factors that influence the pressur~ distribution along the length of the arm. So this method of controlling an' overflow and channelling it in~o the upper level of a ~wo level distributor with the same tapered configuration to the beam ;-cross-section as clearly shown in the enlarged Figures 20 - 23 can function~on a single level or a double level distributor .
arm.
Referring again to the alternate sweep elbow of Figs.
29 and 29A, the'distance e in Fig. 29 represents the displace-ment of the end of the nozzle from the centerline of input to'indicate that rotation of the nozzle will change the head.
It should also be seen as. shown in .Fig~ 29A that the end of the nozzle at 460 is ~lattened to spread the flow o~
fluid upon discharge from the nozzle to accomplish an overlap in the falling streams of adjacent nozzles~

~ .
The graph of Fig. 30 illustrates a curve 470 with the ordinate represent.ing the percent of turbidity and the abscissa representing concentration levels of polyelectrolyte , .' ' ' ,,';.

~ . -113- ' ~

~.. . . : .

feed. This curve there~orc shows the optimum concentrâtion of polyelectrolyte fee~l for maxirnum removal o suspended mat-ter. This is importan~ with resp~ct to the further operative embodiments of my system which utilizes polyelec-trolyte feed for removal of suspended matter.
INJ~CTION MIXING SYSTEM WITH CONTACT TANK
The injection mixing system wi-th a contact tank is seen in Figs. 31 - 34 of the drawings. With reference to these figures, the numeral 500 indicates generally a large contact tank of substantially rectangular section which incor-porates an influent trough 502 as best seen in Fig. 32, a contact tank or trough 504 and an ef~luent -trough 506. ~n influent pipe 508 direc~ influent into a bundle of pipes in- !
dicated generally by numeral 510 through an appropriate valve - manifold arrangement indicated generally by numeral 512. The pipe bundle S10 receives the influent rom the pipe 508 and first of all passes the influent through a respective injection mixing elbow 514, as best seen in Fig. 34, and described more fully hereinafter, and thence through downstream flat plate mixing orifices 516 and 518, and thence to the influent trough ;
502 for discharge thereinto through a hypobolic t~ansformed ; '7' diEfuser 520. The flow from the influent trough 502 into the ~ ;
contact chamber 504 is by appropriate sluice gates 522, as ~-controlled by an operator station 524 as understood by those skilled in the art. The flow from the contact tank 504 into the effluent trough 506 is past an overflow weir 526~

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The dctclils of the injection mixing clbow 514, as seen in Fig. 3~1 comprlses a ~0 pipe elbow 530 with a flat plate orifice 532 connected at the downstream end of the pipe separate bet~een the flanges between the elbow 530 and the next downstream pipe section 534 In order to achieve effi-cient mixing of ozone for example as a typical disinfection medium, injection is achieved through an injection tube 536 positioned on the axis of Elow oE pipe 534 but extending rom -the elbow 530 as illustrated in Fig 34l this type of injection mixing being described in my above-identified eaxlier patents The flow is indicated by arrows 538 Because of the system parameters for which the par-ticular injection mixing system shown in Figs 31 - 34 was designed, the influent pipe 508 was a 48" diameter duct and it was manifolded into twelve independent lines indicated by the pipe handle 510 It is to be noted that the manifold is approximately ~' 6" of the floor of the contact tank 504, and the pipe bundle 510 are comprised of 12-inch diameter pipe proposed to be made of polyvinyl chloride They are located 12 inches off their centerline above the floor of the tank In addition to the in]ection mixing orifice in the injection mixing elbow 514 as described above, there are 50 feet downstream which is 50 diameters of the pipe ~anything in excess of 40 diame*ers being preferred) subsequent flat -plate mixing orifices 516 and 518 are provided The influent then after having a full injection mix-ing ~hr~-gh ~lbow 512 and fla- plate orifices 516 and 518 has a ' .

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t'horouc~h concentration oE ozone or any other injected medium, and thence tlle Elow procceds to the normal influent trough location 502 at the end of the contact -tank. The influent mixing lines move vertically up through the cont~ct chamber 504 and -traverse the wall. between the influent trough and the contact tank. ~t the bottom edge of the injection mixing pi-ping, the flow out into the influent trough 502 is through the hyperbolic transform diffuser 520, which directs flow out~
ward from the pipeline onto the wall, and which generates a hyperbolic sheet on the wall with mixing of the material pre-sently in the influent trough 502. The resultant mixed product :
, ' then traverses the sluice gates 522 into each of the four - ' .,~
independent channels as divided by the divider walls 504a, and best seen in Fig. 31, in the contact tank 504.
'The effluent trough 506 discharges to a 6' diameter ' effluent pipe 560 as seen in Figs. 31 and 32. It should also be understood that sampling connections may be made on the pipe . bundle 510 for the sampling of dissolved oxygen and pressure. . .,~ ;
Normally, the effluent channel itself would be sampled for dis- :
20 solved oxygen and/or for biological testing to confirm the .
absence of fecal coliforms in excess of specification require~
:"~
ments. A typical specification requirement might be 200 fecal '.~.; ':`.' , . : , , coliforms per 100 ml. This is a very high level and it is ,.' , ;
possible to achie~e less than 2 fecal coliforms per lU0 ml ;~
utilizing a one percent concentration ozone injectlon at elbows, .,..' ~
512. , . , ,.,'. ;, .' Referring again to the hyperbolic diffuser 520, it ' ..
should be understood that this section is a transformed hyper-,. ,,: :
bolic sectïon which decelerates the flow. The flow impingeS , . .~; :

: ~

~116- ~
~' .

'iL5 on the influent trouc~h w~ll where it mixes with th~ txouc~h contents before the mi:cture pass~ through -the sluice g~tes of the influen-t trough and into the contact tank proper. The difuser 520 actually increases in area along the flow path and the elbow sec-tion in such a way as to decelerate the flow.
The`deceleration is lntentlona1 and is intended to produce a hyperbolic sheet on the impinging wall. The diffuser should not diverge more than 7 in the channel, otherwise boundary layer separation will occur. However, for practical economic reasons it is more convenient to use a conventional elbow dif-fuser instead of fabricating a special piece of equipment for this purpose. It should be unders-tood that most of the necessary injection mixin~ and contact has occurred in pre- ~-ceeding sections of the 12" diameter line~ i.e. the pip~ bundle 510, which are the actual elements utilized for in~ection mixing, and contact of whatever disinfectant which is used, which may be either the ozone systems described previously, or chlorine solutions in w~ter.
In the configuration described above with reference to F~gs. 31 - 34, the number of elements passing through the contact tank in an actual system design was proportioned on the basis of an available head of 12 1/2 pounds per square inch, which corresponds to approximately 26' of water. Of the available 26' of water head, 16' of water was utilized in the actual pressure drop in the 12" pipes, of which there are 1~, ln the condition where the flow is nAximum for the plant. Ihe ~.

,' ~ . : : : ' - - - : ~ ' . : :

s maximum dcsign flow for t~lis configuration is one hundred million gallons per da~. Thus, -th~ pr~ssure drop is a rela-tively conservative f;gure llndcr the circumstances and -the pressure excess is available because this is a physical treak-ment plant. t~here the pressure drop might be more conserva-tive, the pressure could be con~rolled and a reduction in the number of pipes would be possible, that is in the 12 elements of pipe, by changing the diameter from, for example, 12", up to perhaps l6" or larger. But, consideration must be given to the necessity of having preferably at least 40 diameters between mixing orifices so that the overall system length is ' . .
of the order of 120 to 150 diameters.
A further limitation and consideration that must be incorporated into all plant designs is a possible requirement for de-oxygenation o~ the final effluent. Thi5 can be done in a number of ways. One way would be to inject sulfur dioxide, which would de-oxidize the ozone or chlorine in the final effluent, and would furthermore remove the oxygen excess present. A second possibility is to use thiosulfate, a chemi~
cal reagent which destroys ozone and/or chlorine and will reduce the oxygen concentrations. A third possibility would be to use a mechanical type de-aerator, such as a Cochxane Feed-Water Eleater De-Aerator, used conventionally on boiler `~
feedwater systems. The dissolved oxygen specification maximum ` ;
for this aesign is presently at a nominal vaIue of 20 milli- ~`
grams per liter. This would eit~ler restrict the ozone capa~
~;~ city available for feed, or wo~ld require de-oxygenation by the means set forth above.

~ ' ' .
': :~ : : :

: :

., l~t~ S
.
~CTIV~IrJ'D SL11DCi. .'~ 'l'lON SYSTEM
Fig, 35 illustcates an activated sl~dge aer~tion system in schcm~ic oL-M. ~t should be unde~stood that for normal aeration in an activated sludge system approximately 15,000 cubic feet per pound is utilized, which means 100 pounds of air per pound of BOD or 20 pounds of oxygen per pound BOD, and in effeet represents S~ efficiency. With the system described hereinbelow 75 to lS0 cubic feet of air per pound is utilized which means 5 to 10 pounds of air per pound of BOD or l to 2 pounds of oxygen per pound of BOD or a 50%
to 100~ efficiency range. ;
Referring to Fig. 35, the numeral 600 represents an act~vated sludge tank. Suction is taken from one or more places on the tank near to the bottom outside edge by one or more appropriate low head centrifugal pumps indicated by nu-meral 602 through suction lines 604. Pump 602 then discharged through lines 606 back into a substantially central and upward-ly directed outlet or discharge line 608 near the bottom center ``
o~ tank 600. This creates a vorter flow in the eliptical paths shown by arrows 601 and insures that all liquid in the tank will tend to flow or move around the path. There should not be any stagnant areas.
In order to inject air then into this coniguration, appropriate air compressors 610 are connected by line 612 to direct air into the discharge line 606 through approximately the same type of injection mixing system shown in the injec- ;~
tion elbow 514 of Fig. 34. This achieves ma~imum diffusio~ ~
of the air within the effluent from the pumps 602, suppresses ~-radial concentration gradients, and gives an extremely effici- ~ `
ent way of aerating the activated sludge. Normally the pump 602 will be a low head, high volume pump which is convention-ally available.

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Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A surge suppression system for dampening surge pressures, which is characterized by:
a force main carrying a liquid, a flat plate orifice, said flat plate orifice causing a downstream vena contracta portion in said liquid, said flat plate orifice located in said main, the diameter of said orifice ranging from about 0.7 to about 0.9 of the diameter of said main, an injector means for introducing an amount of a gas into said main, said injection means having a small pipe, said pipe having a tip, said gas flowing through said pipe tip, said pipe tip located in said vena contracta por-tion so that said gas is dispersed into said liquid, said small pipe tip being located at about 0 25 to about 0.5 main diameters downstream from said flat plate ori-fice, said vena contracta portion located in the central portion of said main, and the amount of said introduced gas being in excess of that required to saturate said liquid so as to dampen surge pressures.

2. A surge suppression system for dampening surge pressures according to claim 1, wherein said main contains at least one turbulence causing device located downstream from said high turbulence causing device, said downstream device being a flat plate orifice.

3. A surge suppression system for dampening surge pressures according to claim 2, including a downstream turbulence causing device being located at least 40 main diameters downstream.

4. A surge suppression system for dampening surge pressures according to claim 1, wherein said gas is selected from the group consisting of oxygen, ozone in a carrier gas, nitrogen, carbon dioxide, air, natural gas, exhaust gas and distillate gas.

5. A surge suppression system for dampening surge pressures according to claim 1, wherein said force main is located in a system selected from the class consisting of a waste water collection system, a waste water treatment system, and a fluid transmission system.

6. A surge suppression system according to claim 1, wherein the location of said small pipe tip is from 0.36 to 0.39 main diameters downstream.

7. A surge suppression system according to claim 6, wherein said pipe tip has a small taper.

8. A surge suppression system according to claim 7, wherein said pipe tip is located at about 0.375 diameters downstream from said flat plate orifice.

9. A surge suppression system according to claim 1, wherein said injected gas is selected from the class con siting of oxygen, ozone in a carrier gas, nitrogen, carbon dioxide, air, natural gas, exhaust gas and distillate gas.

10. A surge suppression system according to claim 9, wherein said carrier gas is selected from the class consisting of air, oxygen enriched air, and oxygen.

11. A surge suppression system according to claim 9, including a downstream turbulent causing device being located at least 40 diameters downstream from said flat plate orifice.