GB1587205A - Process for the treatment disinfection neutralisation and/or detoxification of heavily polluted waste waters - Google Patents

Description

(54) PROCESS FOR THE TREATMENT, DISINFECTION, NEUTRALIZATION ANDIOR DETOXIFICATION OF HEAVILY POLLUTED WASTE WATERS (71) We HILGERS GMBH UMWELT- TECHNIK & Co. K.G. of 2-6 Gartenweg, 5421 Fachbach/Bad Ems, Federal Republic of Germany; a German company do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a process for the treatment, disinfection, neutralization and/or detoxification of heavily polluted waste waters, and by such term there is intended to be included sewage in general.

The sterilizing of waste waters by prolonged heating or by the addition of suitable chemical agents, such as chlorine, is known. In the conventional disinfection with chlorine, substantial quantities of chlorine have to be added to the waste water and long reaction times are necessary. Both requirements are uneconomical and often difficult to meet. Furthermore, the inevitable heavy chlorination of the water involved in the process has to be considered an undesired outcome.

As a remedial measure a device has been proposed, in which waste water is disinfected in a tank by the addition of chlorine and air. In this device, the tank is provided with a mixing mechanism and, via a sieve and an intermediate tank, is both filled up with and drained of waste water, whereby comminutable solids are communited in the intermediate tank by the use of cutting heads. However, this known device has the disadvantage that the waste water is not disinfected sufficiently during the short dwell period. Based on exhaustive investigations, it has been possible to establish that the decisive destruction process of the bacteria during the chlorination takes places in tap water and in waste water in the first seconds after the addition of chlorine, i.e. in the phase of the socalled "primary bacterial count drop", which is generally believed to be caused by HOC1, i.e. hypochlorous acid. This phase is followed immediately by the so-called "secondary bacterial count decrease", which proceeds relatively at a slow pace and is caused by the effect of chloramines, which result from the reaction of chlorine with ammonium compounds. Immediately after the mixing with the water or the waste water, the active chlorine is reduced catalytically within a very short time to energy-poor levels and the phenomenon known as "chlorine collapse" takes place, whereby the chlorine collapse is not a process occurring independently of the destruction of the bacteria, but rather the chlorine collapse and the destruction of the bacteria are inseparable processes, i.e. the chlorine is not consumed only by the reaction with organic substances but at the same time also by reaction with microorganisms. Consequently, in order to make a maximum use of the "primary bacterial count drop", the chlorine has to be brought into contact as quickly as possible with the microorganisms to be destroyed in the state of its maximum activity, i.e. at its highest energy content.

The above basic findings are given due consideration in a known process for the disinfection of waste water by means of chlorine in a tank in which the waste water is pumped in a circulatory manner, and during the circulation, the waste water is mixed with air while the amount of chlorine required for the disinfection is added suddenly to the circulating waste water; in which the readily communutable solids contained in the waste water are communited during the circulation; in which the not-readily communu able solids contained in the waste water, which have a higher specific gravity than the waste water, are deposited in such a manner that they are flushed out by the waste water during circulation. The device for carrying out this process, which is also known, is characterized also in that a pump is connected with its outlet to the top end of a tank, and with its inlet to the top end of a smaller chamber, which is connected in turn on one side with the other end of the tank, and on the other side with a waste water source, and that said tank is provided with a device for the introduction of air and for the stirring of the waste water and air mixture as well as with a device for the sudden introduction of a sertain amount of a chlorine containing compound.

Scientists have investigated independently of one another the process described above using said device, certain of these investigations are now listed: a. Medical Director Prof. Dr. med. L. Popp Comment to the question "Chemical or thermal disinfection of infections hospital sewages?" of 27.11.1967.

b. Univ. Prof. Dr. med. 0. Guthof in an expert comment of 3.1.1968.

c. Medical Director Prof. Dr. med. L. Popp in "Gesundheitswesen und Desinfektion" (Public Health and Disinfection), preprint from issue 8/68.

d. Chemical Inspection Office of the city of Emden, Chemical Director Dr. Gunther, in a test report dated 3.12.1969 on the disin fection of ship sewage.

e. Priv. Doz. RMD. Prof. Dr. W. Steuer and RMR. Dr. U. Lutz-Dettinger in "The Hospital", issue 3/1970.

f. Expert survey of the Institute for Water, Soil and Air Hygiene of the Federal Public Health Office, by Dir. a. Prof. Dr. med.

Gertrud Muller and Exec. Dir. a. Prof. Dr.

rer. nat. Walter Niemitz.

g. Medical Director Prof. Dr. med. L. Popp in a comment of 15.1.1973.

The above discussions show that heavily polluted sewages, including their sludge components, can be disinfected by means of chlorine to the extent required only when the described process conditions (homogenization, intermixing of air, batchwise addition of the quantity of disinfectant required for disinfection) are observed. It is thereby with the scope of this recognised process to admix air forcibly or under control to the sewage and sludge mixture during the homogenization phase, which is effected generally by means of pumps or granulators and to then periodically extract small quantitics of the homogenized sewage and sludge mixture, into which the similarly smaller quantities of disinfectant required for the disinfection are injected batchwise under intense stirring with the provision of a reaction time of 1 to 3 minutes. With regard to the disadvantages of the continuous dropwise addition of the disinfectant, Med. Dir. Prof. Dr. L. Popp has ascertained already in the publication given under C): Plants which are equipped with a disinfectant apportioning device and a dosing device complete with dosing nozzle connected to the former, over which the disinfectant is added periodically batchwise or continuously dropwise to the sewage and sludge mixture, are also not satisfactory. In addition to the fact that the destruction defect on colibacteria attainable in such devices is often only of the order of 95%, there is a further disadvantage in that the dosing nozzle is choked within a relatively short time by chloride deposits and that the operator of such a plant is obliged to clean the nozzle at relatively short intervals to prevent a complete failure of the plant. The resulting maintenance costs force the operator of such a plant to search for ways and means which will enable him to reduce the maintenance costs without a degradation of the destruction effect, and thereby he is bound to try to dispense with the maintenance cost-causing dosing nozzle, whereby he will establish, possibly unknowingly, the advantageous process conditions described above.

The interested specialist ascertains meanwhile, on the basis of the literature generally available, and particularly of the technical periodicals, that there are only two disinfection processes comparable from the point of view of their effect, namely, on the one hand the chemical disinfection under the process conditions described initially, and on the other hand the thermal disinfection, in which the sewage including its sludge parts is subjected continuously or batchwise during prescribed periods to temperatures of 95"C to 1 180C. In a known installation of this type the infectious sewage is fed to a collecting tank, from which the plant is put into operation through a warning or signalling device in such a way that the sewage entering the collecting tank is circulated and homogenized by a crusher, that a pressure pump conveys part of the homogenized sewage continuously to a thermal disinfection plant, which includes a first tank, which is operated with high pressure steam at a pressure of at least 2.5atm and in which the homogenized sewage is heated up to 110 C, that the heated sewage is fed subsequently to a second tank and leaves said tank only after a predetermined retention time and is conveyed to a cold water cooler, in which the homogenized sewage is cooled down to the desired sewer entry temperature.

Another known installation improves the plant described above by enabling heat recovery to take place. This is achieved by pre-heating the homogenized partial quantity in a first tank up to 100 C and by raising its temperature to 110 C in a second tank by the addition of heating steam. After the retention time in the third tank, the hot sewage is returned in countercurrent through the first tank, which it leaves at a temperature of about 10 C higher than the one at which the partial quantity entered the first tank initially.

In another discontinuous-type plant, a collecting tank is filled first and the thermal disinfection plant is put then into operation in such a way, that a pulverizer fills discontinuously a second tank up to a predetermined level, that the pulverizer is stopped then and heating steam is introduced in the second tank until the sewage has reached the required disinfection temperature, that the heating steam supply is stopped then and the heated sewage is left for a predetermined time in the second tank, and that the disinfected sewage is pumped then to the sewer with simultaneous addition of cooling water in order to lower the temperature of the sewage entering the sewer to the prescribed values.

With these known thermal disinfection plants it is possible to achieve as a rule destruction effects which are comparable to those obtained by the initially described disinfection process; however, the attainment of this objective involves expenditures which, in comparison with those of the plants operating on the principle of the chemical disinfection process, have to be considered as unjustified. Furthermore, particularly in the retention tank of such plants, there are sludge deposits and cakings which build up, over an extended period of operation, to a thickness which cannot be heated up anymore to the required disinfection temperature via the warm sewage and sludge mixture. This results in the deposit layers being continuously infected anew and forming inevitably in the end breeding places for bacteria, spores, fungi and worm eggs.

Finally, German Auslegeschrift 1114 444 has made known a plant for the automatic disinfection of sewage, particularly from hospitals with isolation stations, by using a collecting tank and by applying pressure and temperatures of over 1000C, which are characterized in that at least one crushing unit is arranged before the collecting tank, said unit processing the solid matter in the sewage to grit size and that at least one pump unit serves for the extraction of the sewage and solid matter mixture from the collecting tank, said pump unit being followed by at least one basic heat exchanger operated in the known manner in countercurrent as well as one steam-heated peak heater, whereby a stand pipe, the length of which determines the pressure in the basic heat exchanger and in the traversed part of the peak heater, is provided for the discharge of the disinfected matter mixture from the basic heat exchanger; that the pump unit is designed so as to ensure that the speed of the sewage and solid matter mixture in the basic heat exchanger and in the peak heater is of the order of 800 mm per minute.

Neither does this known installation make it possible to avoid the dangerous and disadvantageous maintenance work required because of the caking, as in order to ensure an efficiency of the disinfection temperature it is necessary to provide also in this case a retention stage, as indicated in the expert survey dated 27.10.

1958 of Prof. Dr. W. Kikuth and Prof. Dr.

Pothmann with the supplement dated 11.2.

1963, wherein it is stated among other things: "The tested plant is equipped with a retent ion stage, the useful volume of which corresponds to a retention time of about 8 minutes. Owing to the larger cross-sectional area of the retention stage, the fluid speed is reduced to such an extent that the retention stage operates as sediment filter. This means that the settlable matter is not driven first upwards with the fluid through the retention stage, but rather retained in suspension.

The floating matter is retained by the settl able matter so that a filter screen is formed.

This is carried through the retention stage only when its resistance has increased to such an extent that it is lifted by the diffus ing water.

As a result of this design measure, the matter to be disinfected contained in the sewage is subjected to the disinfection temperature at a retention stage volume of 7 minutes - 21 minutes at a retention stage volume of 8 minutes - .24 minutes." The necessity of providing a retention stage is indicated obviously also in the text of German Auslegeschrift 1114 444; as can be deduced from colum 2, line 45 to column 3, line 24 thereof.

In addition to the fact that this advantageous design of the plant in accordance with German Auslegeschrift 1114 444 confirms indirectly the formation as well as the necessity of removing cakings, the exemplary proposal of using acids and the like as flushing or solvent fluids is in acceptance of the negative effects which are attributed in accordance with column 1 of said document to the chemical disinfection plants.

Acids are known to attack not only the sealings of pipe conduits but also the whole plant, unless the plant has been protected by special, expensive measures. Besides, the mixture of acid and sludge produced in the cleaning of the plant cannot be introduced as such in the sewer, usually an exclusively chemical neutralization of this mixture is necessary.

In addition, the sewage sludge discharged with the acid is highly infectious and therefore has to be disinfected again; this means that this infectious, neutralized sedimentation sludge has to be fed again to the disinfection plant, which results in an additional loading of the plant and in an increase of the investment, servicing and maintenance costs.

On the other hand, the interested specialist establishes with satisfaction, quite independently of the question regarding which of the two types of processes described above should be preferred in the end, that scientists as well as users and manufacturers of plants operating in accordance with said processes fully agree that there does not seem to be an absolute certainty regarding the destruction of dangerous bacteria, viruses, spores, fungi and worm eggs by the processes and plants known until now. Consequently, the aim of the present invention is to provide a process of the nature described initially, which makes it possible to use the advantages of the known processes described above but avoids their negative effects.

It is an object of the invention to design the process in such a way that it would be possible, on the one hand, to treat individually the urban, hospital and industrial waste waters, while providing at the same time, on the either hand, the possibility of bringing together the different waste waters after a certain treatment stage and of then treating them jointly. Further more, a possibility should be indicated of purifying, disinfecting, neutralizing and/or detoxicating waster waters of one type by means of waste waters of another type which have been treated already to a certain extent previously.

Another significant object of the invention is to indicate ways and means of subjecting the sewage components as far as possible to a recuperation or re-utilization process, thereby relieving the environment and enabling at the same time the observance of legal impositions and regulations as they exist already today and may be expected to exist necessarily in the future, with due consideration of economical requirements. Furthermore, the invention is designed to assist the general effects aimed at refuse disposal, to contribute and help in the recovery of the environment, and to preserve and protect against destruction the few still existing areas with intact environment. Finally, the invention should indicate possibilities of counteracting the permanent lowering of the ground-water level which is necessary for the ensurance of the drinking water supply, of reducing the squandering of precious drinking water and of ensuring the soil irrigation of water-poor regions; last but not least, the invention should be consistent with the present requirements for an increase in the quality of living through an improved environment.

According to the present invention there is provided a process for the treatment, disinfection, neutralization and/or detoxification of heavily contaminated waste waters, in which the as-supplied waste water is subjected to the following treatment stages: a. the waste water is homogenized by means of the particle-wise comminution of the solid matter contained therein, and the homogenized mixture is brought to an approximately neutral pH-value by the addition of a neutralization agent, with, if required, continuous circulation and stirring, b. the neutralized homogenized mixture is aerated, i.e. enriched with oxygen by a forced through turbulence, with a subseq uent disinfection to cause a primary bacterial count drop by means of a shock wise or sudden addition of a disinfecting agent, preferably of a chlorine-containing disinfectant, as well as a rapid thorough mixing with the disinfecting agent, the disinfected homogenized mixture, after the running-off of an after-reaction time, and a subsequent dechlorination if required, being either directly treated as at f) or is further treated without observance of the after-reaction time, as follows: c. the disinfected homogenized mixture is subjected to a pH value change by the dosed addition of a neutralization agent e.g.

aluminium sulphate or waste pickling liquor, so that a flocculation takes place, in case of need with the addition of an auxiliary flocking agent, and the disinfected and neutralized as well as flocculated homo genized mixture is separated into a solid and a fluid phase, d. the fluid phase in the form of clear water, to which in case of need phosphate is added for hardness bonding purposes, or from which hardness is extracted, is supplied for re-use as industrial water, for spray-irrigation in view of a soil biological treatment and raising of the ground water level, for soil irrigation or for an absolutely safe destruct ion of disease germs, particularly spores, fungi and worm eggs to a further disinfection preferably a thermal disinfection, e. the solid phase is supplied in the form of disinfected sludge to a composting, to a re-utilization facility as fertilizer or to a dry sludge production facility, f. whereby the as-supplied waste water is fed to the individual treatment stages contin uously or batchwise and treated waste water of another nature is added, preferably under a controlling dosing, to the disinfected homogenized mixture in accordance with b) or to the resulting fluid phase in accor dance with c), to alter the pH thereof.

Also in accordance with the invention there is provided a process for the treatment, disinfection, neutralization and/or detoxification of heavily contaminated waste waters, in which the as-supplied waste water is subjected to the fol- lowing treatment stages: a. the course solid matter is removed from the waste water in the form of course sludge, the course sludge is collected, continuously circulated and homogenized by a particle wise comminution of the solid matter, b. a disinfectant, preferably calcium hydroxide, is added to the course sludge-free waste water in such a manner that a positive electro static charging is produced, which effects a flocculation of the fine and finest solid matter particles together with the destroyed disease germs, in case of need with the add ition of an auxiliary flocking agent, as well as effecting a thorough turbulence of the waste water, so that a pre-decontaminated, alkaline water and an alkaline fine sludge are formed, which are further treated independently of one another in such a manner that c. the residual solid matter components are removed from the pre-decontaminated water by filtering and that clear water results, in case of need with a preliminary lowering of the pH-value to a neutral value by the dosed addition of a neutralization agent, e.g. waste pickling liquor, aluminium sulphate or chloride, and thereby a complete flocculation is achieved, d. the clear water is supplied for re-utilization as industrial water, to a spray-irrigation facility for soil biological treatment, to raise the groundwater level or soil irrigation, or, for an absolutely certain destruction of disease germs, such as spores, fungi and worm eggs, to a further disinfection, preferably to a thermal disinfection, or supplied to a receiving water, e. the alkaline fine sludge is fed to the coarse sludge and is pumped and mixed together with the latter in such a manner that the homogenized coarse sludge is disinfected as far as possible and the alkaline fine sludge is neutralized, while the residual solid matter obtained by c) is supplied either to a com posting, a reutilization as fertilizer, a dry sludge production facility or similarly to the homogenized coarse sludge, and that f. the disinfected coarse sludge, mixed with the neutralized alkaline fine sludge, is supplied as a neutral sludge to a sludge in cinerator, possible to a composting or dry sludge production facility whereby the as-supplied waste water is fed to the individual treatment stages continuously or batchwise, and treated waste water of another nature is added, preferably under a controlled dosing, to the disinfected, pre-decontaminated alkaline water in accordance with b) or to the resulting clear water in accordance with c), to alter the pH thereof.

In this respect, it is particularly advantageous if the coarse sludge-free waste water, brought by the dosed adding of calcium hydroxide to a pH-value of about 12, is made to settle and flocculate.

Both processes described above are characterized in that oil and greases are removed from the homogenized mixture or the coarse sludgefree waste water and that, when using calcium hydroxide as disinfectant, this is added preferably as a solution, particularly as a 1% pollution.

Another feature consists in the fact that the auxiliary flocking agent is prepared as a 1% solution, left for a swelling time of one-hour, and subsequently diluted to a 1% solution, and added in quantities of 2 to 3 litres referred to 1 m3 waste water to the disinfected homogenization mixture or to the disinfected, coarse sludge-free waste water or turbid water.

Aluminium or fernic chloride can be utilized as neutralization agent; similarly, sodium hydroxide or sodium carbonate (soda) can be added proportionally by quantity to the waste water instead of calcium hydroxide.

The invention is characterized in that a waster water of another nature, preferably an already decontaminated, neutralized, disinfected and/or otherwise treated waste water is added to the disinfected homogenized mixture or to the pre-decontaminated waste water in such a manner that the addition of the waste water of another nature results in a change of the pH-value of the homogenized mixture and of the pre-decontaminated waste water or of the turbid water.

The waste water of another nature may be a waste water from pig fattening facilities, which has been previously treated as follows: a. pig sewage from dry fattening facilities is collected, relieved batchwise of the decant able solid matter in a decanter, the fluid phase (i.e. waste water) being further treated and the decanted solid matter supplied to a comprising plant or for fertilizing purposes, whereas the sewage resulting in wet fattening facilities is supplied as a whole to the follow ing further process, b. the waste water is homogenized by circulat ion and particlewise comminution of the solid matter, enriched with air, and disin fected by the addition of a disinfectant, preferably by the dosing of chlorine, to effect a primary bacterial count drop, whereby the chlorine is added in such a manner that the carbamides contained in the waste water are destroyed also in the destruction process of the disease germs, and that the disinfected waste water, in case of need after a predetermined reaction time, is supplied either to the disinfected homogenized mixture, i.e. the disinfected, pre-decontaminated waste water of conventional nature, particularly domestic sewage, possible after a previous dechlorination, and is further treated together with it or c. after the predetermined reaction time, par ticularly of a reaction tome of about one hour, the waste water is circulated and red uced to a pH-value of about 5.8 by the addition of a neutralization agent, preferably aluminium sulphate or waste pickling liquor, that after an additional predetermined reaction time, particularly of a reaction time of about half an hour, the waste water is raised to a higher pH-value, preferably pH 6, by the addition of potassium silicate, and made to flocculate, in case of need with the addition of an auxiliary flocking agent, and that the disinfected turbid water is supplied either to a receiving water, i.e. to a turbid water obtained from waste waters of another nature, preferably domestic sewage, after a previous dechlorination if required, and further treated jointly with the latter or d. the waste water is relieved of sedimentation or floating sludge and clear water flows off and is supplied to clear water obtained from waste waters of another nature and con veyed together with the latter to a re-utiliz ation or further treatment facility or supplied directly to a spray-irrigation facility in view of soil biological treatment and raising of the ground water level, whereas the flocculated sludge is supplied together with the sedimentation or the floating sludge to a composting facility, to a further utilization as fertilizer or, to a dry sludge production facility.

The clear water obtained in accordance with d) is dechlorinated and, in case of need, phosphate is added to it for hardness bonding or hardness is extracted from it. In case of a heavier pollution, chlorine, aluminium sulphate, potassium silicake and auxiliary flocking agents are added advantageously to the waste water in a proportion by weight in grams of preferably 50 : 400 : 40 1.

The waste water of another nature may be a chrome-containing industrial waste water which has previously been treated as follows: a. the chrome-containing industrial waste water, to which fresh water is added if requir ed, is subjected to a time-limited thorough turbulent motion, adjusted subsequently to a pH-value of 2.5 by means of a set value comparison-controlled dosing of sulphuric acid, and treated then with a reducing agent, preferably sodium bisulphite, until a control device indicates a permanent surplus of reducing agent, b. the chrome-reduced industrial waste water is mixed thoroughly with flushing waste waters, and is then supplied either to the disinfected homogenized mixture obtained from waste waters of another nature, par ticularly domestic sewage, i.e. to the disin fected pre-decontaminated waste water in view of changing the pH-value, and treated then further jointly with the latter or c. the waste water is adjusted to a neutral pH value by means of a set/actual value com parison-controlled dosing of acid, or lye, preferably waste acid or waste alkali, and supplied to the turbid water obtained from waste waters of another nature, preferably domestic sewage, and further treated then jointly with the latter, whereby the treatment of the chrome-containing industrial waste water is carried out preferably batchwise in a buffer tank.

The waste water of another nature may be a cyanide-containing industrial waste water, which has been previously treated as follows: a. the cyanide-containing industrial waste water, to which fresh water is added if required, is subjected in case of need to a time-limited thorough turbulent motion, and alkalized by the addition of a lye, e.g.

sodium lye, particularly waste alkali, and adjusted preferably to a pH-value 10 to 11, b. the alkalized cyanide-containing was kup to one hour, b. the potato peeling water, interspersed with finely ground peels, produced in the subseq uent peeling of the washed potatoes is collected and subjected to a settling time of up to four hours, c. the potato cutting water produced in the subsequent slicing of the washed and peeled potatoes is collected and subjected to a settling time of up to eight hours so that the earthy, peeling and starch sludges are collected separately and the turbid waters obtained in this way are brought together and treated further jointly in such a manner that d. a disinfectant, preferably chlorine, is added proportionally by quantity to the concentr ated turbid waters and thoroughly mixed with same by the swirling of the turbid waters with a simultaneous aeration as well as an adjustment of the turbid waters to a pH-value of about 8 by means of the dosing of acid or lye, e. the turbid waters are made to flocculate by means of the subsequent dosing of a waste pickling liquor or of a metal in-bearing agent and sodium thiosulphate, with the addition of a flocking agent if required, so that a bacteria-free clear water results, which is conveyed preferably at least partially for reutilization purposes as potato wash water or for another utilization as service or industrial water, or to which clear water obtained from waste waters of another nature, particularly domestic sewages, is added and further treated or used then jointly with it, while f. the earthy sludge and the sedimentation sludge obtained in accordance with e) are conveyed together to a dump or to sludges obtained from waste waters of another nature and treated or used further then jointly with same, particularly processed into humus, g. the residual moisture is removed from the peeling sludge in a filter, preferably over a vacuum band filter, and conveyed in view of its reutilization as fodder, while the fluid removed from it is added to the turbid waters to be adjusted in accordance with d) to a pH-value of about 8, h. the residual moisture is removed from the starch sludge in a filter, preferably over a vacuum band filter, and conveyed either in view of its further utilization as fodder or to a food production facility using potato starch, while the fluid removed from it is added to the turbid waters to be adjusted in accordance with d) to a pH-value of about 8.

In this process, the peeling of the potatoes is carried out preferably using steam, and the potato steam peeling water resulting in this way amounts to about twice the quantity of the starch-compounded potato cutting water, and in case of need the turbid waters relived to a large extent of peels, i.e. starch containing components, after the settling time are subjected jointly to a treatment into clear water, which is refuse then completely as potato wash water, while the soil and potato wash water is subjected to a separate treatment.

The sedimentation sludge removed from the potato peeling and cutting turbid water is conveyed, as dry sludge if required, to a dump, while the earth-rich sludge removed from the potato washing is preferably composted.

The waste water of another nature can consist also of a mixture of industrial domestic, hospital and/or other waste waters, which is contained in a raw water, e.g. river or brook water, and which has been previously treated as follows: a. the coarse impurities are removed first from the waste and raw water mixture, collected and homogenized by particlewise commun ution if required, enriched with air, and subjected to an oxidation process, b. the water relieved of coarse impurities is neutralized, adjusted preferably to a pH value of about 8 by the addition of a lye, c. the water mixture relieved of coarse impur ities is mixed in the turbulent flow process, i.e. in a state of high turbulence, with a simultaneous enrichment with air or oxygen, with a quantity of disinfectant proportional to the water mixture, preferably chlorine in the form of hypochlorite, and subjected in case of need to a reaction time with the disinfectant, d. the disinfectant, slightly alkaline water mixture is transferred to an acid, preferably slightly acid or neutral range, and made to flocculate, whereby the flocking process is accelerated if required by means of the addition of a flocking agent, preferably at a rate of 1 g per 1 m3 water, and a dechlorination is carried out previously, and the clear water is conveyed, in case of need after previous hardness degree adjustment, i.e. hardness removal, to a plant irrigation or drinking water treatment facility, or irrigated by spraying for groundwater level raising and soil-biological treatment purposes, while e. the sludges obtained in accordance with d) are neutralized and conveyed to a sludge processing facility or dump, and the separat ed, possibly homogenized, coarse sludge in accordance with a) is dumped or composted, in case of need after previous mixing with the sludges obtained in accordance with d).

The invention proposes further that the prepared, disinfected sludges be treated prefer ably into humus, by adding said sludges to the compostable, fine-grained substances obtained from a refuse treatment plant, by piling it admixed with said substance in a stack and by subjecting it to a rotting process.

In this process it is sometimes advantageous to mix only part of the sludge with the com postable substances obtained from a refuse treatment plant, whereas the other part is fed to a refuse incinerator.

If the treated sludges are compounded with combustibles, the sludges can be supplied to a firing facility, preferably to a power plant or to a district heating plant. The combustibles considered in this respect are, for example, fluid or pasty combustibles, preferably oils and oil sludges. If the sludges are admixed with solids, particularly fine-grained combustibles e.g. coal sludges, carbon black, breeze and sawdust, said combustibles can be fed, in case of need after their previous degassing, to a dry sludge production and/or briquetting plant.

The fluid phase resulting in this process can be added either to the homogenization mixture, i.e. to the pre-decontaminated waste water, or to the turbid waters obtained from the waste waters.

The flocking residual solid matter particles are removed preferably by means of backwashable filters from the turbid waters, the filters are backwashed with disinfected clear water obtained from the waste waters, and the backwashed, solid matter particle-carrying flushing water is fed to the waste water homogenization mixture, i.e. to the pre-decontaminated waste water, or to the separated coarse sludge, and further treated jointly with it.

In accordance with another feature of the invention, the clear waters, chemically disinfected and neutralized, in case of need dechlorinated, are subjected to a thermal after-disinfection to ensure an absolutely certain destruction of disease germs, particularly of fungi, spores and worm eggs.

To this end, a thermal disinfection process, preferably with heat recovery, is used, to which the clear water is supplied possibly from a buffer tank in such a manner that it is heated in a first heat exchanger to a temperature of about 1200C, and supplied then to a downstream reactor tank, which it leaves at a temperature of about 150"C, and passed then in countercurrent through the first heat exchanger, in which it is cooled by the inflowing, still unheated clear water to a temperature of about 300C, whereby the thermally after-disinfected clear water is supplied either to a sewer, i.e.

receiving water, or to a reutilization as industrial water, or to a spray-irrigation facility for soil-biological treatment purposes, or to a drinking water treatment plant.

The heat exchange takes place in the reactor tank by means of a thermal oil, which is heated up to a heating facility t. a temperature of from 2000C to 4000C as a function of the outflow temperature of the heated clear water.

In accordance with another feature, the after-disinfection of the clear waters is made in the known manner by means of superheated steam, which is injected into the clear waters, preferably until same are heated up to the desired disinfection temperature.

In accordance with the proposed object, the processes described above establish the conditions for an economical treatment of waste waters and for reducing at the same time decisevely the present wastefulness of precious drinking water as well as for a profitable utilization of sludges produced in the waste water treatment.

Furthermore, the invention makes it possible to increase in an advantageous way the as far as possible only slightly polluted or unpolluted raw water reservoir required for the domestic drinking water supply by introducing the disinfected, neutralized and decontaminated, in case of need also dechlorinated clear waters produced in the waste water treatment process in a pond or lake, preferably in an artificially constructed pond or lake, which features a rich rush-vegetation, whereby the pond or lake has a clay-like base bottom, which is covered by a gravel packing, which carries in turn the rush-holding soil.

The clay-like base bottom is thereby sloped preferably to one side and the gravel bottom is inclined possibly together with the soil, especially in the direction of the pond or lake centre.

The clear waters are supplied to the pond or lake at a temperature of about 10 to 350C, preferably 15 to 250C.

In a development of the invention, the clear waters are supplied to the pond or lake over pipe lines, which they leave through slotshaped openings, which are provided preferably in the pipe line sections which lie in the area of the depression and are not covered by the soil.

Furthermore, this process can be achieved also by providing an artificial river instead of a pond or lake.

If freshwater fish, and particularly tench, trout, carp and/or pike, are exposed in the pond, lake, brook or river, it is possible to feed into the clear water inflow the waste water produced in a dairy-farm. The waste water fed into the clear water inflow may originate in a butter-and-cream producing dairy-farm, said waste water having been previously treated as follow: a. the highly whey-like waste water is adjusted by the dosing of an acid, e.g. waste pickling liquor, to a pH-value of about 4, possibly with simultaneous addition of a disinfectant, e.g. chlorine, b. the slightly acid waste water, possible after the running-off of a predetermineable reaction time, is raised to a pH-value of 5.6 to 5.8 by the dosing of calcium hydrite, sodium hydroxide or sodium carbonate, and flocculates, whereafter the slightly acid defloculated waste water is subjected preferably to a thorough turbulence, particularly to a turbulence with an upwards ascending turbulent flow, possibly with a simultaneous strong aeration and addition of the disinfectant, e.g. chlorine, and the floating sludge is added to the sludge produced by flocculation, so that turbid water will result, which either c. is supplied to the turbid waters obtained, from waste waters of another nature, part icularly domestic sewage, and treated then further jointly with same, preferably how ever d. is raised to a pH-value of about 6.2 by the dosing of water glass, particularly potassium silicate and made to flocculate, so that clear water will result, which is fed into the fish pond clear water inflow, and e. the sludges obtained by flocculation and floatation are compounded with a binding agent.

The waste water fed into the clear water inflow may originate in a butter-cream- and cheese-producing diary-farm, said waste water having been previously treated as follows: a. the whey-like waste water is adjusted by the dosing of calcium hydrite, sodium hy droxide or sodium carbonate to a pH-value of about 8, possibly with simultaneous addition of a disinfectant, preferably active chlorine, b. the slightly alkaline waste water, possibly after the expiration of a predetermineable reaction time, is reduced by the dosing of a metal salt, e.g. pickling liquor, preferably waste pickling liquor, to a pH-value of 5.6 to 5.8 and made to flocculate, whereafter the slightly acid waste water is subjected preferably to a thorough turbulence, particularly to a turbulence with an upwards ascending turbulent flow, possibly with a simultaneous strong aeration and addition of disinfectant, e.g. chlorine, and the floating sludge is added to the sludge produced by flocculation, so that turbid water will result, which either c. is supplied to the turbid waters obtained from waste waters of another nature, par ticularly domestic sewage, and treated then further jointly with same, preferably how ever d. is raised to a pH-value of about 6.5 by the dosing of water glass, particularly potassium silicate and made to flocculate, so that clear water will result, which is fed into the fish pond clear water inflow, whereas e. the sludges obtained by flocculation and floatation are compounded with a binding agent.

In this process it has been found to be particularly advantageous to provide a reaction time after each pH-value adjustment or change, which is proportional to 25 to 35% of the waste water flow rate, and to provide a dosing of flocking agent after or associated to the dosing of agents for the changing of the pHvalue.

The disinfectant, particularly active chlorine, can be added by dosing to the waste water simultaneously with, or immediately after the first pH-value adjustment, with a simultaneous or previous aeration, i.e. enrichment with oxygen; however, it is advantageous to add the disinfectant to the waste water in a state of thorough turbulence and aeration.

Furthermore, the invention proposes to add to the sludges obtained by flocculation and flotation from dairy waste waters sludges obtained from waste waters of another nature, and particularly sludges which are available from an animal feeding facility and which have a binding or similar effect on the above mentioned sludges. Suitable for this purpose are for example the peeling and/or starch sludges produced in the processing of potatoes into chips, french fried potatoes and mashed potatoes, which are mixed with the dairy sludges, whereby the sludge mixture is supplied either directly to a wet feeding facility or to a plant processing it into dry fodder, possibly with the addition of a preservation agent compatible with the food regulations.

Similarly it is possible to supply the whey sludges, admixed with the beet pulp and/or molasses produced in the sugar extraction from beet, either directly to a wet feeding facility, to a silage-making facility or to dry fodder processing facility, possibly with the addition of a preservation agent compatible with the food regulations.

In addition, limestone powder, cement, gypsum and sawdust can be added to the whey sludges, and the sludges bound in this way can be dumped, preferably composted, possibly with a previous admixing with compost able sludges obtained from waste waters of another nature and/or with compostable substances produced in refuse treatment.

In a development of the invention, it is possible to extract clear water from water heavily contaminated with waste waters of various natures, the clear water, possibly dechlorinated and having a certain degree of hardness or being hardness-relieved, being fed into the clear water inflow of a lake, pond, brook or river or sprayed for irrigation in biological treatment purposes, particularly in order to raise the groundwater-level, in that a. the untreated water and waste water mix ture, possibly after a previous mechanical separation of coarser impurities, is centri fuged batchwise and separated at least into a light water and a heavy water, and the light water is drawn-off continuously where as the heavy water is drawn-off only at the end of the centrifuging time, b. the light water, containing oils, greases, solvents and specifically light suspended matter, is subjected to a stabilization phase, and air is added to it at a low pressure in such a manner that the oils, greases and solvents float and form a comparatively dense film on the light water surface, that the level of the light water is raised at the end of the stabilization phase, the film is removed and the pre-decontaminated light water is supplied to the homogenization mixture, i.e. to the coarse matter-relieved waste water of another nature and treated then further jointly with it supplied to the separately collected heavy water, c. the heavy water admixed with the pre-decon taminated light water and adjusted by the dosing of acid or lye, preferably waste acid or alkali, to an approximately neutral pH value, is transferred such as to a slightly alkaline range, d. a disinfectant, preferably active chlorine is added proportionally by quantity shock wise, suddenly or batchwise to the water mixture made up of heavy and light water, and is mixed with same within the shortest time possible with a simultaneous or previous aeration, whereby the disinfectant is added by dosing to the water mixture preferably in a condition of thorough turbulence and enrichment with air or oxygen of said water mixture, and the water mixture is subjected to a reaction phase to the stage of the secondary bacterial count decrease, that e. the disinfected, preferably slightly alkaline water mixture is transferred to an acid, preferably slightly acid, range, and made to flocculate, in case of need with the addition of a flocking agent, wherein a waste pickling liquor is used for the transfer of the water mixture from the slightly alkaline to the slightly acid range, f. the flocculated, slightly acid sludge is neutralized and deposited, preferably com posted, by the admixing with slightly alkaline sludges extracted from other waste waters or by the addition of comparatively small quantities of calcium hydrite, sodium hydroxide of sodium carbonate, g. the slightly acid disinfected water, is raised by the dosing of a neutralization agent to an approximately neutral pH-value arid made to flocculate out completely, so that clear water will result, which is supplied preferably dechlorinated to a drinking water reservoir.

In addition to this, the invention makes it possible to adjust the raw water and waste water mixture by the dosing of an acid or lye to a neutral pH-value, to subject it subsequently to a time-limited stabilization phase, with the introduction of air at a low pressure into the untreated and waste water mixture in such a manner that the specifically lighter components float and form a film at the water mixture surface, which is removed after the completion of the stabilization phase by raising the water level and floating off and the thereby predecontaminated raw and waste water mixture is subjected to a stepwise further treatment without any centrifuging.

If the waste water of another nature is a dye waste, said waste water is treated previously in accordance with the invention in such a manner that a. the dye waste is drawn-off continuously or batchwise from a receiving buffer and ad justed under the control of a pH-probe by the dosing of calcium hydrite, sodium hydroxide or sodium carbonate to an approximately neutral pH-value, preferably to a pH-value of 8, possibly with a contin uous stirring, i.e. turbulence of the waste water, b. the neutral, preferably slightly alkaline waste water, possibly after the expiration of a reaction tome, is reduced to a pH-value of about 6.8 by the dosing of a neutralizat ion agent, preferably aluminium sulphate, which results in a flocculation, possibly under the effect of an additional flocking agent, and the sedimentation sludge and a turbid water with a slight colouring, especially a yellow colouring, are drawn off separately, that c. the turbid water is subjected to turbulence, preferably in an upwards ascending turbu lent flow, aerated, i.e. enriched with oxygen and disinfected by the dosing of a disinfect ant, especially chlorine, and made to floccu late out completely as a result of the oxi dation occurring thereby, so that the clear water is extracted, said clear water being supplied to a re-utilization facility as industrial water, to a spray-irrigation facility for soil-biological treatment and/or groundwater level raising purposes whereas, d. the sedimentation sludges produced in accordance with b) and c) are supplied together with the floating sludge produced in accordance with c) to a dumping, to an incinerator or to a dry sludge production facility, whereafter the bacteria-free clear water is preferably dechlorinated and either provided with a degree of hardness of having hardness revoked.

A further features of the invention refers to the fact that the waste water of another nature is a waste water originating in a slaughter house, a sausage factory, i.e. in a meat processing factory, containing blood, intestinal contents, talc, meat and bone pieces, as well as other animal components, which is treated previously in such a manner that a. the solid matter contained in the waste water is particlewise comminuted and the grease and talc parts contained in the homogenized waste water are made to float and removed, whereafter the homogenized waste water is subjected, possibly before the floating of the grease and talc parts, to a swirling and aeration as well as-in accordance with the principle of the primary bacterial count drop-to the application of a proportional quantity of disinfecting agent and mixed with same within the shortest time possible, b. the homogenized waste water, relieved of grease and talc parts, is transferred by the dosing of an acid to an acid range, adjusted preferably to a pH-value of 3 to 4, and the blood components in the waste water are made to coagulate, c. the acid waste water is raised then to a pH value of 6.5 to 6.8 by the dosing of a lye, preferably of a lye based on calcium hydrox ide, sodium hydroxide or sodium carbonate, and flocculated, possibly by means of a flocking agent, whereafter, simultaneously with the raising of the pH-value, the waste water is possibly aerated i.e. enriched with oxygen and mixed within the shortest time possible with a proportional quantity of disinfectant, especially chlorine, added by dosing, so that d. the sedimentation sludge produced by flocculation as well as the floating sludge produced by floating are removed and the resulting turbid water is spray-irrigated for biological treatment purposes or supplied to a trickling filter, conveyed to a receiving water or discharged to the sewer, raised preferably to a pH-value of 8 and caused to flocculate, possibly by addition of a flocking agent, so that clear water is extracted, which is conveyed preferably to a re-utilization facility as industrial water, while the sludges resulting in the individual process stages are processed into fertilizer or compost, and the grease and talc components obtained by floatation are supplied to a soap production facility.

The turbid waters obtained in accordance with d) are conveyed after their neutralization and possible dechlorination to a fish-pond, while the clear water obtained in accordance with d) is dechlorinated, phosphate is possibly added to if for hardness binding, or hardness is removed from it, the latter process being carried out preferably by means of an ion exchanger.

As an alternative, the invention proposes for the treatment of slaughter-house sewages that a. the grease and talc components in the sewage is floated by means of a controlled air supply, removed and conveyed to a soap production facility, b. the sewage relieved of grease and talc com ponents is conveyed to a coarse material trap, and that the solid matter removed from the sewage is collected separately and pos sibly treated then further, c. a controlled quantity of acid, preferably a pickling agent is added by dosing to the pre decontaminated sewage, and that the sewage is adjusted to a pH-value of 2.5 to 4.5, preferably 3 to 4, d. by means of a subsequent raising of the pH value to a value under 7, however, not less than 6.3, by the controlled dosing of a lye, preferably a waste alkali, the noxious matter contained in the sewage is flocculated and deposited, whereby, simultaneously with the raising of the pH-value or after the sedimentation, the sewage is aerated, i.e. enriched with oxygen and chlorinated by means of a quantitativeproportional controlled process, that e. subsequently the germ-free turbid water is subjected by the dosing of an aluminate and possibly of another a flocking agent to a residual-flocculation and sedimentation and that the resulting clear water is supplied to a re-utilization as industrial water, in case of need after a previous dechlorination as well as providing a degree of hardness or removing hardness and that the sludges produced in the individual process stages is processed into fertilizer or compost, whereby said sludges are mixed previously preferably with the sludge obtained from the coarse separator.

In an additional modification of the treatment of such waste waters the invention provides that the waste water of another nature is a waste water originating in a slaughterhouse, a sausage factory, i.e. a meat processing factory, containing blood, intestinal contents, talc, grease, meat and bone pierces, as well as other animal components, said waste water being treated previously in such a manner that the waste water relieved of grease and talc components by floating is comminuted particlewise in a continuous circulation, adjusted by the dosing of soda to a pH-value of about 8, reduced then by the dosing of a metal salt to a pH-value of under 7 and made to flocculate, possibly by means of the addition of a flocking agent, and that the resulting turbid or clear waters are subsequently aerated and compounded with chlorine and supplied to a receiving water, especially to a rush receiving water, possibly after the expiration of an after-reaction time.

The process fundamentals described above are outstandingly suitable also for the treatment of waste waters which originate in animal.

breeding farms, especially dog-breeding farms, veterinary clinics and laboratories for the testing of medicines on animals. Such waste waters, which contain as a rule a high concentration of disease germs, particularly worm eggs, are treated in accordance with the invention in such a manner that a. the waste water is circulated, particle-wise comminuted, enriched with air, and disin fected by the dosing of chlorine to produce a a primary bacterial count drop, whereby the chlorine is added proportionally by quantity in such a way that the carbamides are de composed simultaneously with the destruct ion of the disease germs, b. the disinfected waste water is supplied, after a reaction time if required, either to the disinfected homogenization mixture, i.e. to the disinfected pre-decontaminated waste water of conventional nature, particularly domestic sewage, possibly after a previous dechlorination, and treated then further jointly with it, preferably c. after the expiration or elapse of the pre determined reaction time of up to about one hour, is circulated and adjusted by the dosing of a neutralization agent, preferably aluminium sulphate, to a pH-value of about 5.8, that after the elapse of an addit ional predetermined reaction time, especially of a reaction time of up to about half an hour, the waste water is adjusted by the dosing of water glass to a higher pH-value, preferably pH 6, and made to flocculate, with the addition of a flocking agent if required, and that the disinfected turbid water, relieved of carbamides, is supplied either to a receiving water, i.e. to the turbid waters obtained from waste waters of another nature, preferably domestic sewage, after a previous dechlorination if required, and treated then further jointly with it or d. the turbid water is relieved of sedimentation and floating sludge and clear water flows off, which is either discharged to the sewer or supplied to clear water obtained from waste waters of another nature, and con veyed then jointly with it in view of a further utilization or treatment, or supplied directly to a spray-irrigation facility for a soil-biological treatment and the raising of the groundwater level, preferably e. far an absolute certain destruction of disease germs, particularly fungi spores and worm eggs, subjected to a thermal after-disinfection, whereby the thermal disinfection process used is preferably of the type with heat recovery, to which the clear water is supplied possibly from

The invention proposes additionally that the waste water be cooled, before or simultaneously with its treatment, down to a temperature of under +30"C, preferably under +25 C; that the oil, tar, sand and other impurities be extracted from the waste water in a continuous process, and that the impurities extracted from the waste water be removed discontinuously, preferably continuously; that the floating oil be removed continuously over several outlets, arranged preferably at different levels; that the oil outlets arranged at different levels be provided to follow the course of an imaginary spiral.

The process fundamentals described above are also outstandingly suited for increasing and improving the capacity and efficiency of existing waste water treatment plants, or for adapting the existing plants to modified conditions with due consideration of the economical requirements. In accordance with the invention this is made possible in that the obtained turbid or clear waters are supplied over a trickling filter to a biological treatment plant.

This is particularly efficient if the water supplied to the trickling filter is a turbid or clear water obtained especially from domestic sewage, disinfected chemically and/or thermally, neutralized and/or detoxicated.

The above description of the invention can provide on the basis ofjust a few selected examples the process fundamentals, which enable the specialist to treat waste waters enriched with precipitable noxious matter in an economical manner so that the solid, fluid and/or dissolved, i.e. emulsified waste water components can be supplied for a re-utilization or further utilization with due observance of the laws, regulations and prescriptions on pollution control in force at present.

WHAT WE CLAIM IS: 1. A process for the treatment, disinfection, neutralization and/or detoxification of heavily contaminated waste waters, in which the assupplied waste water is subjected to the following treatment stages: a. the waste water is homogenized by the particle-wise comminution of the solid matter contained therein and the homo genized mixture is adjusted by the addition of a neutralization agent to an approximately neutral pH-value; b. the neutralized homogenized mixture is aerated, i.e. enriched with oxygen by means of a forced thorough turbulence and with a subsequent disinfection to cause a primary bacterial count drop by means of a shock wise or sudden addition of a disinfectant, as well as of a thorough admixing with the disinfectant; the disinfected homogenized mixture, after the running-off of an after reaction time, being either directly treated as at f) or is further treated without obser vance of the after-reaction time, as follows: c. the disinfected homogenized mixture is subjected to a pH-value change by the dosing of a neutralization agent, so that a flocculation takes place, and the disinfected and neutralized as well as flocullated homo genized mixture is separated into a solid and a fluid phase; d. the fluid phase is supplied as clear water for reutilization as service water, to a spray irrigation for soil-biological treatment, raising the groundwater level, i.e. soil irrigation, or is subjected to a further disinfection; e. the solid phase is supplied in the form of disinfected sludge to a composting, to a reutilization as fertilizer or to a dry sludge production facility; f. whereby the as-supplied waste water is conveyed to the individual treatment stages continuously or batchwise and treated waste water of another nature is added to the homogenized mixture disinfected in accor dance with b) or to the fluid phase produced in accordance with c), to alter the pH there of.

2. A process for the treatment, disinfection, neutralization and/or tedoxification of heavily contaminated waste waters, in which the assupplied waste water is subjected to the following treatment stages: a. the coarse solid matter is extracted from the waste water in the form of coarse sludge, said course sludge is collected, circulated continuously and homogenized by particle wise comminution of the solid matter; b. a disinfectant is added in such a manner to the waste water relieved of the solid matter that a positive electrostatic charging is produced, which effects a flocculation of the fine and finest solid matter particles together with the destroyed disease germs as well as effecting a thorough turbulence of the waste water, os that a pre-decontaminated alkaline water and an alkaline fine sludge are formed, which are treated further indep endtly of one another in such a manner that c. the residual solid matter components are removed by filtering from the pre-decontam inated, alkaline water and clear water results, d. the clear water is supplied for reutilization as service water, to a spray-irrigation for soil-biological treatment, raising of the groundwater level, i.e. to a soil irrigation facility, subjected to a further disinfection, or supplied to a receiving water, e. the alkaline fine sludge is supplied to the coarse sludge and pumped and mixed with same in such a manner that the homogenized coarse sludge is disinfected as far as possible and the alkaline fine sludge is neutralized, whereas the residual solid matter obtained in accordance with c) is supplied either to a composting, to a reutilization as fertilizer, to a dry sludge production facility or to the homogenized coarse sludge, and that f. the disinfected coarse sludge, admixed with

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (41)

**WARNING** start of CLMS field may overlap end of DESC **. The invention proposes additionally that the waste water be cooled, before or simultaneously with its treatment, down to a temperature of under +30"C, preferably under +25 C; that the oil, tar, sand and other impurities be extracted from the waste water in a continuous process, and that the impurities extracted from the waste water be removed discontinuously, preferably continuously; that the floating oil be removed continuously over several outlets, arranged preferably at different levels; that the oil outlets arranged at different levels be provided to follow the course of an imaginary spiral. The process fundamentals described above are also outstandingly suited for increasing and improving the capacity and efficiency of existing waste water treatment plants, or for adapting the existing plants to modified conditions with due consideration of the economical requirements. In accordance with the invention this is made possible in that the obtained turbid or clear waters are supplied over a trickling filter to a biological treatment plant. This is particularly efficient if the water supplied to the trickling filter is a turbid or clear water obtained especially from domestic sewage, disinfected chemically and/or thermally, neutralized and/or detoxicated. The above description of the invention can provide on the basis ofjust a few selected examples the process fundamentals, which enable the specialist to treat waste waters enriched with precipitable noxious matter in an economical manner so that the solid, fluid and/or dissolved, i.e. emulsified waste water components can be supplied for a re-utilization or further utilization with due observance of the laws, regulations and prescriptions on pollution control in force at present. WHAT WE CLAIM IS:

1. A process for the treatment, disinfection, neutralization and/or detoxification of heavily contaminated waste waters, in which the assupplied waste water is subjected to the following treatment stages: a. the waste water is homogenized by the particle-wise comminution of the solid matter contained therein and the homo genized mixture is adjusted by the addition of a neutralization agent to an approximately neutral pH-value; b. the neutralized homogenized mixture is aerated, i.e. enriched with oxygen by means of a forced thorough turbulence and with a subsequent disinfection to cause a primary bacterial count drop by means of a shock wise or sudden addition of a disinfectant, as well as of a thorough admixing with the disinfectant; the disinfected homogenized mixture, after the running-off of an after reaction time, being either directly treated as at f) or is further treated without obser vance of the after-reaction time, as follows: c. the disinfected homogenized mixture is subjected to a pH-value change by the dosing of a neutralization agent, so that a flocculation takes place, and the disinfected and neutralized as well as flocullated homo genized mixture is separated into a solid and a fluid phase; d. the fluid phase is supplied as clear water for reutilization as service water, to a spray irrigation for soil-biological treatment, raising the groundwater level, i.e. soil irrigation, or is subjected to a further disinfection; e. the solid phase is supplied in the form of disinfected sludge to a composting, to a reutilization as fertilizer or to a dry sludge production facility; f. whereby the as-supplied waste water is conveyed to the individual treatment stages continuously or batchwise and treated waste water of another nature is added to the homogenized mixture disinfected in accor dance with b) or to the fluid phase produced in accordance with c), to alter the pH there of.

2. A process for the treatment, disinfection, neutralization and/or tedoxification of heavily contaminated waste waters, in which the assupplied waste water is subjected to the following treatment stages: a. the coarse solid matter is extracted from the waste water in the form of coarse sludge, said course sludge is collected, circulated continuously and homogenized by particle wise comminution of the solid matter; b. a disinfectant is added in such a manner to the waste water relieved of the solid matter that a positive electrostatic charging is produced, which effects a flocculation of the fine and finest solid matter particles together with the destroyed disease germs as well as effecting a thorough turbulence of the waste water, os that a pre-decontaminated alkaline water and an alkaline fine sludge are formed, which are treated further indep endtly of one another in such a manner that c. the residual solid matter components are removed by filtering from the pre-decontam inated, alkaline water and clear water results, d. the clear water is supplied for reutilization as service water, to a spray-irrigation for soil-biological treatment, raising of the groundwater level, i.e. to a soil irrigation facility, subjected to a further disinfection, or supplied to a receiving water, e. the alkaline fine sludge is supplied to the coarse sludge and pumped and mixed with same in such a manner that the homogenized coarse sludge is disinfected as far as possible and the alkaline fine sludge is neutralized, whereas the residual solid matter obtained in accordance with c) is supplied either to a composting, to a reutilization as fertilizer, to a dry sludge production facility or to the homogenized coarse sludge, and that f. the disinfected coarse sludge, admixed with

the neutralized alkaline fine sludge, is supplied as neutral sludge to a sludge incin erator, to a composintg or dry sludge pro duction facility, whereby the as--supplied waste water is conveyed continuously or batchwise to the individual treatment stage, and treated waste water of another nature is added to the disinfected, pre-decontaminated alkaline water in accor dance with b) or to the clear water obtained in accordance with c), to alter the pH thereof.

3. A process as claimed in Claim 2, in which the waste water relieved of coarse sludge is adjusted by the dosing of calcium hydroxide to a pH-value of about 12, and made to settle and flocculate.

4. A process as claimed in Claim 1, 2, or 3, in which oils and greases are removed from the homogenized mixture, or from the waste water relieved of course sludge, and that when using calcium hydroxide as disinfectant this is applied in the form of a solution.

5. A process as claimed in Claim 1,2 or 3, in which a flocking agent is prepared as a 1% solution, subjected to a swelling time of one hour, and diluted then to a 0.15to solution and, referred to 1 m3 waste water, added in quantities of 2 to 3 litres to the disinfected homogenized mixture or to the disinfected waste water relieved of coarse sludge.

6. A process as daimed in Claim 1,2 or 3,.

in which aluminium chloride or ferric chloride is utilized as the neutralization agent.

7. A process as claimed in any one of Claims 2 to 6, in which the disinfectant added to the waste water is sodium carbonate.

8. A process as claimed in any preceding claim, in which the waste water of another nature is a waste water from pig fattening facilities which has been previously treated as follows: a. the pig sewage produced in dry fattening facilities is collected, relieved batchwise of the decantable solid matter in a decanter, the fluid phase (i.e. waste water) is further processed and the decanted solid matter is supplied to a composting plant or for fertilizing purposes, whereas the sewage produced in wet fattening facilities is supplied as a whole to the following further process, b. the waste water is homogenized by means of circulation and particlewise comminution of the solid matter, enriched with air, and disinfected by the addition of a disinfectant, to effect a primary bacterial count drop, whereby the disinfectant is added in such a manner that the carbamides contained in the sewage are destroyed simultaneously with the destruction of the disease germs, the waste water then optionally being further treated as follows: c. the waste water is circulated and adjusted by means of the dosing of a neutralization agent, to a pH-value of about 5.8, and is thereafter adjusted to a higher pH-value, by the dosing of potassium silicate and made to flocculate, d. the waste water is relieved of sedimentation and floating sludge so that clear water results, the flocculated sludge being supplied together with the sedimentation and float ing sludge to a composting facility, to a further utilization as fertilizer or to a dry sludge production facility.

9. A process as claimed in Claim 8, in which the clear water obtained in accordance with d) is dechlorinated and phosphate is added thereto or hardness is removed therefrom.

10. A process as claimed in Claim 8 or 9, in which chlorine, aluminium sulphate, potassium silicate and flocking agents are added to the waste water in a ratio by weight of50:400:40:1.

11. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a chrome-containing industrial waste water, which has been previously treated, as follows: a. the chrome-containing industrial waste water is subjected to a time-limited thorough turbulence, adjusted by the dosing of sulphuric acid to a pH-value of

2.5, and then treated with a reducing agent until a control device indicates a per manent surplus of reducing agent, b. the chronium-reduced industrial waste water is admixed with flushing effluents, the waste water optionally being further treated as follows: c. the waste water is adjusted by means of the dosing of acid or lye to a neutral pH value.

12. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a cyanide-containing industrial waste water which has been previously treated as follows: a. the cyanide-containing industrial waste water is subjected to a time-limited thorough turbulence and alkalized by the addition of a lye, b. the alkalized, cyanide-containing waste water is subjected to oxidation by means of active chlorine until a control device indicates a permanent surplus of active chlorine, c. the cyanide-decontaminated industrial waste water is admixed with flushing effluents, the waste water optionally being further treated as follows: d. the waste water is adjusted by means of the dosing of an acid or lyr to a neutral pH value.

13. A process as claimed in Claim 12, in which reaction times amounting to 3 to 60 minutes, are observed between the individual treatment stages.

14. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is an industrial waste water which is produced in a straw paper factory and - which has been previously treated as follows: a. the waste water resulting during a one-day production is collected, transferred to the acid range by the dosing of acid and adjust ed to a pH-value of 2 to 5, b. simultaneously with or immediately after the transfer of the waste water to the acid range air is introduced with such an intensity that flocculation takes place, the flocks float and form a comparatively solid sludge layer on the waste water surface, c. the acid water is removed, adjusted by the dosing of a lye to a higher pH-value and made to flocculate out completely, d. the acid, solid sludge and the approximately neutral sedimentation and floating sludges are mixed either with other sludges and subjected to a further treatment or process ing or introduced directly into an incinerator or supplied to a dry sludge production facility.

15. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a waste water produced in the processing of potatoes which has been previously treated as follows: a. the potato wash water, mixed with earth, produced in the washing of the potatoes is collected and subjected to a sedimentation time of up to one hour, b. the potato peeling water, mixed with finely ground peels, produced in the subsequent peeling of the washed potatoes, is collected and subjected to a settling time of up to four hours, c. the potato cutting water produced in the subsequent slicing of the washed and peeled potatoes is collected and subjected to a settling time of up to eight hours, so that the earthy, peeling and starch sludges are produced separately and the resulting turbid waters are combined and then further treated as follows: d. a disinfectant is added proportionally by quantity to the combined turbid waters and admixed with same by swirling of the turbid waters with a simultaneous aeration and adjustment of the turbid waters to a pH-value of about 8 by the dosing of acid or lye, e. the turbid waters are made of flocculate by the subsequent addition of a waste pickling liquor or of another metal ion-bearing compound and sodium thiosulphate, so that a bacteria-free clear water will result, whereas f. the earthy sludge and the sedimentation sludge obtained in accordance with e) are supplied to a dump or to sludges obtained from waste waters of another nature and treated or used then further jointly with same, g. the residual moisture is removed from the peeling sludge over a filter and supplied for a reutilization as fodder, whereas the fluid removed from it is supplied to the turbid waters to be adjusted to a pH-value of about 8 in accordance with d), h. the residual moisture is removed from the starch sludge over a filter, and supplied then either to a reutilization as fodder or to a food production unit using potato starch, whereas the fluid removed from it is supplied to the turbid waters to be adjust ed to a pH-value of about 8 in accordance with d).

16. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a waste water mixture consisting of industrial, domestic, hospital and/or other waste waters, which is contained at a high concentration in a raw water, and which has been previously treated as follows.

a. the coarse impurities are removed first mechanically from the waste water and raw water mixture, said impurities are collected and homogenized, enriched with air and subjected to an oxidation process, b. the water relieved of the coarse impurities is neutralized by the addition of a lye, c. the water mixture free of coarse impurities is mixed in a swirling process, i.e. in the state of a thorough turbulence, with sim ultaneous enrichment with air or oxygen, with a disinfectant, d. the disinfectant, slightly alkaline water mixture is transferred to an acid or neutral range and made to flocculate, e. the sludges obtained in accordance with d) are neutralized and supplied to a sludge utilization or dump, and the coarse sludge separated in accordance with a) is dumped or composted.

17. A process as claimed in any preceding Claim, in which the resulting disinfected sludges are processed by adding to said sludges the compostable, fine-grained matter obtained from a refuse treatment facility, by depositing them in a compounded form in stacks and subjecting them to a rotting process.

18. A process as claimed in Claim 17, in which only part of the sludge is supplied to the compostable matter obtained from a refuse treatment plant, whereas the other part is fed to a refuse incinerator.

19. A process as claimed in any one of Claims 1 to 16, in which the resulting sludges are compounded with combustibles and supplied to a firing facility.

20. A process as claimed in Claim 19, in which fluid and/or pasty combustibles are added to the resulting sludge.

21. A process as claimed in Claim 19, in which the resulting sludges are admixed with solid combustibles and whereby the sludge and combustible mixture is supplied to a dry sludge production and/or a briquetting facility.

22. A process as claimed in any preceding Claim, in which the fluid phase resulting in the dry sludge production is supplied either to the waste water homogenized mixture, i.e. to the pre-decontaminated waste water.

23. A process as claimed in any preceding Claim, in which the flocculated residual solid matter particles are removed from the turbid waters, the filters are backwashed with disinfected clear waters obtained from the waste waters, and backwashing waters carrying the backwashed solid matter particles are supplied to the waste water homogenization mixture, i.e. to the pre-decontaminated waste water or to the separated coarse sludge and treated then further jointly with same.

24. A process as claimed in any preceding Claim, in which the treated waters are subjected to a thermal after-disinfection.

25. A process as claimed in Claim 24, in which the treated water is heated up to a temperature of about 120"C in a first heat exchanger and supplied then to a downstream reactor tank, which it leaves at a temperature of about 1500C, and returned then in countercurrent through the first heat exchanger, in which it is cooled by the inflowing, not yet heated clear water down to a temperature of about 30"C.

26. A process as claimed in Claim 25, in which the heat exchange in the reactor tank is made by means of a thermal oil, which is heated in a heating facility to a temperature of 200"C to 4000C as a function of the outflow temperature of the heated clear water from the reactor.

27. A process as claimed in Claim 24, in which the thermal after-disinfection of the treated water is made in the known manner by means of superheated steam, which is injected into the clear waters until said clear waters have been heated up to the desired disinfection temperature.

28. A process as claimed in any preceding claim, in which the treated waters produced in the waste water treatment are introduced into a pond or lake which contains a rich rush vegetation, whereby the pond or lake has a claylike base which is covered by a gravel packing, which carried in turn a soil which holds the rush vegatation.

29. A process as claimed in Claim 28 in which the base is sloped to one side and in which the gravel bottom is inclined towards the pond or lake centre.

30. A process as claimed in Claim 28 or 29, in which the clear waters are supplied to the pond or lake at a temperature of 10 to 350C.

31. A process as claimed in Claim 30, in which the clear waters are supplied to the pond or lake over pipe conduits and leave the same through slot-shaped openings.

32. A process as claimed in any one of Claims 28 to 31, in which the clear waters are introduced in an artificially constructed brook or river instead of a pond or lake.

33. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a heavily contaminated waste water which has been previously treated as follows: a. the raw water and waste water mixture is centrifuged batchwise and separated at least into a light water and a heavy water, and the light water is drawn-off continuously wherease the heavy water is drawn-off only after the running-off of the centrifuging time b. the light water, containing oils, greases and solvents is subjected to a stabilization phase and air at a low pressure is added to it in such a manner that the oils, greases and solvents float and form a comparatively thick film on the light water surface, in which upon completion of the stabilization phase the level of the light water is raised, the film is removed, and the pre-decontam inated light water is supplied to the homo genized mixture, i.e. to the waste water of another nature relieved of coarser impurities and treated then further jointly with it, supplied to the separately collected heavy water, c. the heavy water is mixed with the pre-decon taminated light water and adjusted by the dosing of an acid or lye to an approximately neutral pH-value, d. a disinfectant is added in a shock or sudden manner or batchwise to the water mixture made up of heavy and light water and ad mixed with same within the shortest time possible with a simultaneous or previous aeration, whereby the disinfectant is added to the water mixture in a state of thorough turbulence and enrichment with air or oxygen, and the water mixture is subjected to a reaction time so as to reach the secondary bacterial count drop, e. the disinfected water mixture is transferred to an acid range and made to flocculate, f. the flocculated, slightly acid sludge is neutralized by admixing with slightly alka line sludges obtained from other waste waters or by adding comparativiely small quantities of calcium hydroxide, sodium hydroxide or sodium carbonate, and dumped, g. the slightly acid, disinfected water is adjusted by the dosing of a neutralization agent to an approximately neutral pH value and made to flocculate out completely so that clear water will result.

34. A process as claimed in Claim 33, in which the untreated water and waste water mixture is adjusted by the dosing of an acid or lye to a neutral pH-value, subjected subsequently to a time-limited stabilization phase and introduced with low pressure air into the raw water and waste water mixture in such a manner that the spcifically lighter components float and form a film at the water mixture surface, which is removed after the completion of the stabilization phase and the thereby predecontaminated raw water and waste water mixture is subjected to a stepwise further treatment without centrifuging.

35. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a dye waste water, which has been previously treated as follows: a. the dye waste water is drawn-off continuously O1 batchwise from a receiving buffer and adjusted, under the control of a pH-probe, by the dosing of calcium hydroxide, sodium hydroxide or sodium carbonate to a approx imately neutral pH-value, b. the neutral, preferably slightly alkaline waste water is lowered to a pH-value of approximately 6.8 by the dosing of a neutralization agent, which results in a flocculation and in the separate production of a sedimentation sludge and of a turbid water with a slight colouring, c. the turbid water is subjected to a turbulence, aerated, i.e. enriched with oxygen, and disinfected by the dosing of a disinfectant and made to flocculate out completely under the effect of the resulting oxidation, so that clear water is obtained, and d. the sedimentation sludges produced in accordance with b) and c) are supplied jointly with the floating sludge produced in accordance with c) to a dump, an incin erator or a dry sludge production facility, whereafter the bacteria-free clear water is dechlorinated and either provided with a degree of hardness or having hardness re moved from it.

36. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a waste water originating in a slaughterohose, a sausage factory, i.e. a meat processing factory, containing blood, intestinal contents, talc, meat and bone pieces, as well as other animal components, which has been previously treated as follows: a. the solid matter contained in the waste water is comminuted particlewise and the grease and talc components contained in the homogenized waste water are made to float and removed, whereby the homogenized waste water is subjected to a turbulence and aeration as well as to the application of a proportional quantity of a disinfecting agent in accordance with the principle of primary bacterial count drop and admixed with same within the shortest time possible, b. the homogenized waste water, relieved of grease and talc components, is transferred by the dosing of an acid to the acid range, and the blood components contained in the waste water are made to coagulate, c. the acid waste water is raised subsequently by the dosing of a lye, to a pH-value of

6.5 to 6.8 and made to flocculate, whereafter, simultaneously with the raising of the pH-value, the waste water is aerated, i.e.

enriched with oxygen and admixed within the shortest time possible with a proportional quantity of an added disinfectant, so that d. the sedimentation sludge produced by flocculation as well as the floating sludge produced by the floatation are extracted, so that clear water is obtained, whereas the sludges produced in the individual treatment stages are processed into fertilizer or compost, and the grease and talc components obtained by floatation are supplied to a soap production unit.

37. A process as claimed in Claim 36, in which the turbid waters obtained in accordance with d) are supplied, subsequently to their neutralization to a fish-pond.

38. A process as claimed in Claim 36, in which the clear water obtained in accordance with d) is dechlorinated and phosphate is added to it for hardness binding or hardness is extracted from it, the latter being effected by means of an ion exchanger.

39. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a waste water originating in a slaughter-house, a sausage factory, i.e. a meat-processing factory, containing blood, intestinal contents, talc, grease, meat and bone pieces, as well as other animal components, which is treated previously in such a manner that a. the grease and talc components of the waste water are made to float by means of a controlled air injection, removed and supplied to a soap production unit, b. the waste water relieved of grease and talc components is supplied to a coarse material trap and the solid matter extracted from the waste water is collected, c. a controlled quantity of an acid is added to the pre-decontaminated waste water and the waste water is adjusted to a pH-value of

2.5 to 4.5, d. the noxious matter contained in the waste water is made to flocculate and settle by the subsequent raising of the pH-value to a value of 6.3 to 7, by means of the controlled dosing of a lye, whereby at the same time with the raising of the pH-value or after the sedimentation, the waste water is aerated, i.e. enriched with oxygen and chlorinated under a proportional quantitat ive control, e. subsequently the germ-free turbid water is subjected by means of the dosing of an aluminate to a residual flocculation and associated sedimentation, and in which the sludges produced in the individual process stages are supplied to a processing into fertilizer or compost, whereby said sludges are admixed previously with the sludge obtained from particlewise comminuted solid matter extracted by the coarse trap from the as-supplied waste water.

40. A process as claimed in any one of Claims 1 to 7 and 36 to 38, in which the waste water of another nature is a waste water originating in a slaughter-house, a sausage factory, i.e. a meat-processing factory, containing blood, intestinal contents, talc, grease, meat and bone pieces, as well as other animal components, which is treated previously in such a manner that the waste water, relieved of grease and talc components by floatation, is particlewise comminuted under a continuous stirring, adjusted by the dosing of soda to a pH-value of about 8, subsequently lowered by the dosing of a metal salt to a pH-value under 7 and made to flocculate and in which the resulting turbid or clear waters are subsequently aerated and compounded with chlorine.

41. A process as claimed in any one of Claims 1 to 7, in which the waste water of another nature is a waste water originating in an animal breeding unit which has been previously treated as follows: a. the waste water is circulated, particlewise comminuted, enriched with air and disinfect ed by the addition of chlorine to effect the primary bacterial count drop, that the car bamides are also decomposed simultaneously with the destruction of the disease germs, b. the disinfected waste water is supplied either to the disinfected homogenized mix ture, i.e. to the disinfected, pre-decontamin ated waste water of a conventional nature, and treated then further jointly with the same, c. after the elapse of the predetermined reaction time, the waste water is circulated and ad justed by the dosing of a neutralization agent, to a pH-value of about 5.8, in which after the elapse of an additional predeter mined reaction time, the waste water is raised by the dosing of water glass to a higher pH-value and made to flocculate, and in which the disinfected turbid water is supplied either to a receiving water, i.e. to the turbid waters obtained from waste waters of another nature, in case of need after a previous dechlorination, and treated then further jointly with same or d. the turbid water is relieved of sedimentation and floating sludge and clear water results, e. for an absolutely certain destruction of disease germs, the waste water is subjected to a thermal after-disinfection, whereby the thermal disinfection process used is of the type with heat recovery, to which the clear water is supplied in such a manner that it is heated i