WO1995013990A1 - Procedes et appareils d'utilisation de micro-organismes dans le traitement de matieres organiques se trouvant dans les eaux usees - Google Patents

Procedes et appareils d'utilisation de micro-organismes dans le traitement de matieres organiques se trouvant dans les eaux usees Download PDF

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Publication number
WO1995013990A1
WO1995013990A1 PCT/GB1994/002556 GB9402556W WO9513990A1 WO 1995013990 A1 WO1995013990 A1 WO 1995013990A1 GB 9402556 W GB9402556 W GB 9402556W WO 9513990 A1 WO9513990 A1 WO 9513990A1
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WO
WIPO (PCT)
Prior art keywords
reaction zone
bacteria
waste water
organic material
organisms
Prior art date
Application number
PCT/GB1994/002556
Other languages
English (en)
Inventor
Michael Ian Lees
Michael Littlewood
Donald Reid
Alan Stephen Ward
Lynne Maclennan
Original Assignee
Ea Technology Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ea Technology Limited filed Critical Ea Technology Limited
Priority to AU10718/95A priority Critical patent/AU1071895A/en
Priority to GB9609460A priority patent/GB2298195B/en
Publication of WO1995013990A1 publication Critical patent/WO1995013990A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/12—Activated sludge processes
    • C02F3/1278—Provisions for mixing or aeration of the mixed liquor
    • C02F3/1294—"Venturi" aeration means
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/12—Activated sludge processes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/10—Biological treatment of water, waste water, or sewage

Definitions

  • the present invention relates to methods of using micro-organisms to treat organic material found in waste water and to apparatus for putting the methods into effect.
  • the present invention is directed towards the treatment of waste water to yield an environmentally acceptable effluent. It is envisaged that the present invention may be used to treat all types of biodegradable waste water or sewage, including municipal, industrial and agricultural waste water.
  • Waste water commonly contains both organic and inorganic solids of various forms.
  • organic material is commonly present in the waste water in solution and as colloidal and/or particulate matter.
  • a standard measure of the organic material present in the waste water is its Biological Oxygen Demand (BOD) .
  • BOD Biological Oxygen Demand
  • Waste water having a high BOD tends to encourage the proliferation of micro-organisms which feed on the organic material.
  • waste water is discharged into natural waters such as rivers.
  • the micro-organisms will consume any oxygen dissolved in the water, resulting in an environment which will not support higher forms of life such as plant life or fish.
  • Discharge of waste water having a high BOD is therefore environmentally unacceptable.
  • the presence of pathogenic micro-organisms and toxic compounds in particular waste waters constitutes a health hazard. Regulations are now being effected in many countries in which the discharge of effluent not environmentally acceptable will incur substantial financial penalties.
  • a typical treatment scheme for treating waste water containing organic material can involve a number of treatment stages although not all of these stages may be necessary for every effluent.
  • a pre-treatment is required if the effluent contains gross inorganic solids or very high concentrations of fats. The pre-treatment stage may also be useful for balancing concentrations if these vary excessively.
  • a primary or pre-biological treatment stage is generally necessary if the waste water contains organic solids which may be readily separable. This pre-biological treatment stage will include a separation stage which produces an organic sludge and an effluent.
  • the effluent from the pre-biological treatment stage is passed to a biological treatment stage which is used to convert organic material still dissolved or held in suspension in the effluent into an organic sludge which can be separated from the effluent, or into mineralised products.
  • the sludge produced by the pre-biological treatment and biological treatment stages may be treated to reduce its volume and to convert it to a more environmentally acceptable form.
  • the effluent from the biological treatment stage may be further treated to reduce the level of fine suspended solids, to reduce the concentration of mineralised products from the pre-biological and biological treatments, or to reduce the concentration of toxic or persistent compounds in the effluent before final discharge into the environment.
  • One widely used aerobic process for such treatment is referred to as the activated sludge process, so called as it involves the production of an activated mass of micro-organisms capable of stabilising a waste aerobically.
  • Organic material in the waste water is converted into a solid form which can be separated from purified water.
  • a portion of the insoluble sludge that is formed is recycled to the aerobic zone to maintain a specific solids concentration and biological activity.
  • the bacteria are the most important micro-organisms because they are responsible for the decomposition of the organic material in the waste water.
  • the bacteria form floes which is a
  • the floes also trap solids in the waste water for subsequent degradation.
  • the metabolic activites of other micro-organisms are also important in the activated sludge system.
  • Protozoa and rotifers act as effluent polishers since protozoa consume dispersed bacteria that have not flocculated, and rotifers consume small biological floe particles that have not settled.
  • the protozoa and rotifers are typically less than 5% of the dry weight in activated sludge solids.
  • a major cost of biological effluent treatment is that associated with the processing of the solid - the thickening, stabilisation and dewatering required to dispose of the sludge.
  • Sludge costs are typically 50% of total treatment costs.
  • Thickening is generally employed to further concentrate the solids in the sludge prior to stabilisation or further digestion. Thickening may be accomplished by gravity thickening, pressing or dissolved air flotation.
  • Various processes have been proposed to stabilise the sludge or to reduce the production of sludge.
  • US-A-4915840 discloses a process involving hydrolysis of the heavy sludge fraction and the use of an auto thermal aerobic digester zone.
  • sewage is charged to a primary clarifier where grit and inorganic and heavy organic materials are separated from the waste water by gravity to leave organic material dissolved or suspended in the water.
  • the effluent from the primary clarifier is then charged to an initial aerobic zone where the organic material remaining in the effluent is contacted with an oxygen containing gas and biologically active organisms. This results in a mixed liquor of liquid and organic solids which is then separated into a heavy sludge fraction and a disposable effluent (which can be discharged to the external environment) .
  • the heavy sludge fraction comprising organic solids and some liquid is hydrolysed by contact with acid or base and the resulting hydrolysed sludge is combined with sediment from the primary clarifier and charged to an auto thermal aerobic digester zone.
  • the extent of hydrolysis is controlled such that the rate of biological digestion in the auto thermal aerobic digester zone results in the production of an effluent containing a preselected concentration of organic matter.
  • a preselected net generation of sludge is produced by the aerobic sludge generating process thereby resulting, in an overall preselected sludge reduction.
  • the mean hydraulic time for the aerobic time was eight hours and the mean hydraulic time for the auto thermal aerobic digester was 18 days.
  • a significant feature of the treatment of sludge is the control of the concentration of micro-organisms present in the aerobic zone. Micro-organisms exposed to organic material in the presence of oxygen will consume the organic material to grow and reproduce. The conversion of organic material to micro-organism biomass is not 100% efficient as some of the organic material is broken down into carbon dioxide and water during the process of respiration required to generate energy for growth and reproduction. In addition, there are maintenance energy requirements by the icrobial cell which is supplied by both substrate breakdown and biomass degradation.
  • the use of the extended aeration process reduces the net production of sludge because it limits the organic material available to the micro-organisms.
  • the rate of production of new micro-organisms is decreased and the natural processes of cell death and endogenous respiration (respiration using the stored organic material in the micro-organisms) result in a net negative growth rate.
  • auto thermal aerobic digestion the digester is operated at elevated temperatures such that the rate of biological digestion is increased at these higher temperatures.
  • the rate of biological digestion is increased in auto thermal aerobic digestion, it appears that the principle of extended aeration is still used as indicated by the hydraulic residence time, in the example of US-A-4915840, of 18 days.
  • the inventors have appreciated that the production of sludge may be controlled or even eliminated by deactivating a proportion of the bacteria present in the system. In this way the total number of bacteria in a reaction zone can be maintained substantially constant whilst maintaining a high rate of aerobic digestion and respiration.
  • the invention provides a method of using micro-organisms to treat organic material found in waster water, the method including the steps of: a) supplying waster water to a reaction zone for aerobic digestion of organic material in the waster water by bacteria; b) removing a portion of the contents of the reaction zone to produce a liquid fraction and a separated sludge fraction; c) returning the whole of the separate sludge fraction to the reaction zone; and d) deactivating a proportion of the bacteria in the reaction zone to modify the concentration of active bacteria in the reaction zone.
  • the inventors have appreciated that, if the quantity of bacteria in the reaction zone is controlled, then sludge generated by the bacteria in the reaction zone may be maintained in the reaction zone instead of having to be separated and treated in a separate process.
  • any sludge removed with the liquid fraction may be separated and returned to the reaction zone and used in the aerobic digestion. Separate treatment of sludge is thereby avoided and the product of the treatment is primarily carbon dioxide and water which can be easily disposed.
  • the organic material supplied to the reaction zone in the wastewater is sufficient for the bacteria population in the reaction zone to be respiring as in a growth phase, preferentially as in an exponential growth phase.
  • the deactivation of bacteria provided by the present invention contributes to reducing bacteria numbers such that the net increase in bacteria within the reaction zone is not in fact exponential.
  • the proportion of bacteria from the reaction zone which are deactivated is sufficient to maintain the concentration of active biomass in the reaction zone substantially constant.
  • the deactivating step uses non-chemical means.
  • non-chemical means to deactivate the bacteria avoids the need to have a separate zone for the deactivation or to provide means for separating the chemicals before the effluent is discharged to the external environment.
  • a second aspect of the invention provides a method of using micro-organisms to treat organic material found in waster water, the method including the steps of: a) supplying waster water to a reaction zone for aerobic digestion of organic material in the waster water by bacteria; and b) deactivating a proportion of the bacteria in the reaction zone by non-chemical means to modify the concentration of active bacteria in the reaction zone.
  • the bacteria are deactivated by breaking up floes of bacteria to provide loose bacterial cells and small floe particles in the reaction zone to enhance consumption of bacteria by higher organisms.
  • a mechanical force is used such as a region of high shear stress.
  • the mechanical force may be generated by a jet of fluid.
  • the bacteria are deactivated during aeration of the reaction zone. In this way, the two steps of deactivation and aeration may be combined.
  • a third aspect of the invention provides a method of using micro-organisms to treat organic material found in waste water, the method including the steps of: a) supplying waste water to a reaction zone for aerobic digestion if organic material in the waste water by bacteria; b) controlling the rate of supply of the waste water to be sufficient for the bacteria population of the reaction zone to be respiring as in a growth phase; and c) deactivating a proportion of the bacteria in the reaction zone to maintain constant the concentration of active bacteria in the reaction zone relative to the organic material.
  • Figure 1 shows schematically an embodiment of an apparatus provided in accordance with the present invention including an aerator effective to modify micro-organisms;
  • Figure 2 shows an embodiment of a venturi aerator for use in the apparatus of Figure 1, the aerator including a nozzle for producing the venturi effect;
  • Figure 3 shows the nozzle of Figure 2 in greater detail.
  • Figure 1 shows, schematically, an apparatus for treating raw unsettled sewage and incorporating the apparatus of the present invention.
  • Rags and other gross solids (“screen solids"), are removed from the raw sewage as the sewage is passed through screens 1.
  • Large inorganic grit solids are removed via the gritting lanes 2.
  • the remaining sewage liquor flows continuously into a well mixed reaction vessel 3 at a controlled rate of between l/6th and l/24th of the volume of the reaction vessel per hour.
  • Treated liquor overflows from the vessel in order to ensure the sewage liquor has a mean residence time in the reaction vessel of between 6 and 24 hours.
  • the sewage liquor is brought into contact with micro-organisms which feed on the dissolved, colloidal and particulate organic material in the sewage liquor.
  • organic material consumed by the micro-organisms are converted into carbon dioxide and water with the generation of energy in a form which may be used by the micro-organisms to grow and reproduce.
  • the rate of growth of a population of micro-organisms is dependent upon a number of environmental factors.
  • the activity of the population is affected by the concentration of nutrient, the level of dissolved oxygen, the temperature and the pH.
  • the level of dissolved oxygen, temperature and pH can be controlled by correct design and operator input.
  • the correct level of nutrient for a process to operate is dependent upon many other factors, not least the history of the micro-organisms and the history of the nutrient supplied. These control the size and the nature of the population of the micro-organisms.
  • the concentration of micro-organisms can greatly exceed the concentration of nutrient. This encourages the growth of protozoa, such as flagellates and ciliates which prey on the simple micro-organisms (bacteria) .
  • the overall rate of growth of the micro-organism population thereby decreases as the number of simple micro-organisms consumed begins to approach the number of micro-organisms produced by cell division. This phase is often known as the declining growth phase.
  • the concentration of nutrients becomes limiting, the micro-organisms begin to respire using nutrients in their own bodies. This phase is known as the endogenous respiration phase.
  • large quantities of cells die and cells lysis or decomposition takes place. This process can release nutrient and cause resynthesis of the population. Indeed, cyclic growth and decline of micro-organism population is often observed in the circumstance of batch feeding of sludge (e.g. in prior art extended aeration treatments) .
  • X ⁇ ⁇ - k g X - k d X dt
  • X the concentration of micro-organisms
  • ⁇ the specific growth rate. This is a measure of the rate of cell division.
  • k is the specific endogenous respiration rate.
  • k is the predatory rate. This is a measure of the feeding of other micro-organisms (protozoa and rotifers) on the bacterial population.
  • k, and k have been combined for analysis purposes, because they typically are only of significance compared to the growth term when retention times are high, food to micro-organism ratios are low and the sludge is in the endogenous respiration phase. The effects of death and endogenous respiration are then hard to separate. Values of (k, + k ) are typically between 0.02 per day and 0.1 per day in this phase. In the exponential growth phase, when food to micro-organism ratios are high, then the specific growth rate can be as high as 5 per day. In the endogenous phase growth rates are below 0.1 per day.
  • Oxygen transfer is a critical feature in waste water treatment and is the limiting factor in many processes, and due to the low solubility of oxygen in solution is very energy intensive.
  • the aeration system developed for this treatment process provides the two prime requirements for successful biological oxidation: efficient transfer of oxygen from the air into the waste water being treated, and strong stirring action to keep the waste water and biomass in intimate contact.
  • the enhanced oxygen transfer and fluid motion across the bacterial cell surface means that substrate uptake by bacteria is also increased and therefore, the substrate in the waste water becomes limiting so that additional energy now required is obtained by the digestion of bacteria by other bacteria, therefore ke increases.
  • the second effect of the system on the microbial population is the creation of conditions favourable to certain protozoa.
  • the shearing effect of the aeration system sloughs off cells from floes and breaks some large floes into smaller ones.
  • the result in shearing a proportion of the floes is an increased availablility of loose bacterial cells for ingestion by ciliated protozoa and rotifers, resulting in increased population sizes of these organisms, and therefore in kd,.
  • the combined result of floe shearing and the increase in oxygen transfer, and therefore substrate uptake rate, is a constant active sludge concentration in the reactor. Furthermore, this is achieved with high feed rates and low hydraulic -r ⁇ sid.en_ce times, and therefore in conditions typical of exponential growth in population in conventional processes.
  • the rate of change of substrate concentration, or alternatively the rate of feed to the process at constant substrate concentration, is controlled by the rate of feeding of the micro-organisms and the numbers of protozoa.
  • the physical stress on the micro-organisms is imposed by an aerator arrangement 4.
  • sludge is removed from the reaction vessel 3 and propelled through a loop 4a, preferentially a closed loop, by a pump 4b.
  • the loop 4a includes a venturi aerator 4c which effects efficient transfer of oxygen from air into the sludge and agitates the treated sludge to keep the sludge and active micro-organisms well mixed.
  • the venturi aerator 4c may be of the self-entraining type, in which the air is introduced purely by pumping sludge through the venturi aerator, or of the blown type, where the self-entrained air is supplemented by additional air supplied to the venturi unit from a low pressure Roots blower 4d which can supply large volumes of air at relatively low pressure ratios.
  • sludge including micro-organisms, is continuously abstracted and circulated through the aeration device.
  • the use of the aerator arrangement enables oxygenation of the sewage liquor and mixing of the sewage liquor/micro-organism mixture to be achieved simply, reliably and with low power consumption.
  • the treated liquor flows into a separation device 5 which is able to separate typically 96% of volatile organic solids and 92% of inorganic solids from the effluent.
  • the separated solids, the solid fraction is returned to the reaction vessel 3 for further treatment.
  • the remaining effluent, the liquid fraction may be subjected to further treatment, "polishing", at 6 to reduce the level of fine suspended solids, reduce the concentration of mineralised products or reduce the concentration of toxic compound before discharge of the final effluent, having a composition within the regulation limits, to the water course.
  • the aerator arrangement 4 also has the effect of shearing some of the floes of bacteria in the sludge to provide loose bacterial cells and small floe particles.
  • An embodiment of a venturi aerator adapted for this purpose is shown in Figures 2 and 3. Unless otherwise indicated, all dimensions shown are in millimetres. Dimensions including the reference NB are nominal bore sizes with normal tolerances.
  • the input to the aerator 4c from the loop 4a comprises a tube 10 through which the sludge flows.
  • the nozzle 12 sits within a T joint 14, of carbon steel, one end of which is joined to the tube 10.
  • the second end of the T joint 14 is joined to an inlet 16 through which air may enter the aerator 4c.
  • the third end of the T joint is joined, via a gate valve 18 to a carbon steel pipe 20 which leads to the reaction vessel 3.
  • a gate valve 18 to a carbon steel pipe 20 which leads to the reaction vessel 3.
  • aerated air flows through the pipe 20, it meets with a second constriction provided by a concentric reducer 22. Turbulence created within the concentric reducer by the constriction results in a region of high shear stress. As the aerated and turbulent sludge flows out of the concentric reducer 22, its pressure energy due to the constriction has been converted into kinetic energy by its acceleration through the constriction. The kinetic energy of the sludge is sufficient to shear floes of bacteria to increase the numbers of loose bacteria and small floe particles in the reaction vessel. These cells and small floe particles can then be consumed by higher organisms such as protozoa and rotifers, thereby increasing the population of these organisms and in effect increasing the rate of predation k,.
  • the aeration vessel is capable of holding a working volume of 400m 3 at a depth of 6 m.

Abstract

Selon l'invention, on traite les matières organiques présentes dans les eaux usées en les faisant digérer en aérobie par des bactéries dans un bassin de réaction. On désactive une proportion de bactéries dans le bassin de réaction afin de modifier la concentration de bactéries actives. On effectue cette désactivation en prévoyant une région de contraintes de cisaillement mécanique élevées dans le liquide afin de briser les amas de bactéries appelés flocs. On obtient ainsi des cellules bactériennes détachées ainsi que des petites particules réunies en flocs qui favorisent le développement d'une population à forme de vie supérieure, les protozoaires et les rotifières, lesquels sont les prédateurs de ces cellules isolées et de ces petites particules. En limitant le niveau de prédation par des formes de vie supérieure, on augmente le taux de mortalité utile des bactéries de telle sorte qu'on peut maintenir, dans la zone de réaction, la biomasse globale à un niveau constant même si des matières organiques en quantité suffisante sont fournies dans les eaux usées pour que la population bactérienne puisse respirer comme dans une phase de croissance. Le taux de respiration élevé en résultant minimise la production globale de boues, sans que la durée de séjour dans la zone de réaction soit excessive.
PCT/GB1994/002556 1993-11-19 1994-11-21 Procedes et appareils d'utilisation de micro-organismes dans le traitement de matieres organiques se trouvant dans les eaux usees WO1995013990A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU10718/95A AU1071895A (en) 1993-11-19 1994-11-21 Methods and apparatus for using micro-organisms to treat organic material found in waste water
GB9609460A GB2298195B (en) 1993-11-19 1994-11-21 Methods and apparatus for using micro-organisms to treat organic material found in waste water

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9323870.7 1993-11-19
GB9323870A GB9323870D0 (en) 1993-11-19 1993-11-19 Methods and apparatus for using micro-organisms to treat organic material found in waste water

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WO1995013990A1 true WO1995013990A1 (fr) 1995-05-26

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AU (1) AU1071895A (fr)
GB (2) GB9323870D0 (fr)
WO (1) WO1995013990A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2766813A1 (fr) * 1997-08-01 1999-02-05 Degremont Procede et dispositif d'epuration d'eaux usees comprenant un traitement additionnel des boues par ozonation
US5948261A (en) * 1998-02-05 1999-09-07 Pressley; Richard L. Process for treating biosolids from wastewater treatment
US6168717B1 (en) 1998-02-05 2001-01-02 Thermal Process Systems, Llc Process for controlling foam in a treatment reactor
US6203701B1 (en) 1998-02-05 2001-03-20 Thermal Process Systems, Llc Process and apparatus for treating biosolids from wastewater treatment
US6719903B1 (en) 1998-02-05 2004-04-13 Thermal Process Systems, Llc Process and apparatus for treating biosolids from wastewater treatment
EP1544171A1 (fr) * 2003-12-17 2005-06-22 L'air Liquide S.A. Procédé de réduction de boues issues du traitement d'eaux usées par oxygénation et action mécanique
US7708885B2 (en) 2001-05-31 2010-05-04 Biothane Llc Anaerobic digestion apparatus, methods for anaerobic digestion and for minimizing the use of inhibitory polymers in digestion
CN107034142A (zh) * 2008-11-28 2017-08-11 泰拉瑞亚控股公司 在异养型微生物中制备特制油

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9920937D0 (en) * 1999-09-06 1999-11-10 Mattison Richard G Process
JP4474930B2 (ja) * 2004-02-02 2010-06-09 栗田工業株式会社 有機性排水の生物処理方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4915840A (en) * 1988-06-07 1990-04-10 Bioprocess Engineering, Inc. Process for sludge reduction in an aerobic sludge generating waste treatment system
US4976863A (en) * 1989-01-26 1990-12-11 Pec Research, Inc. Wastewater treatment process

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3351047B2 (ja) * 1993-09-27 2002-11-25 栗田工業株式会社 生物汚泥の処理方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4915840A (en) * 1988-06-07 1990-04-10 Bioprocess Engineering, Inc. Process for sludge reduction in an aerobic sludge generating waste treatment system
US4976863A (en) * 1989-01-26 1990-12-11 Pec Research, Inc. Wastewater treatment process

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6337020B1 (en) 1997-08-01 2002-01-08 Societe Degremont Method and device for purifying waste water comprising an additional sludge treatment by ozonation
WO1999006327A1 (fr) * 1997-08-01 1999-02-11 Societe Degremont Procede et dispositif d'epuration d'eaux usees comprenant un traitement additionnel des boues par ozonation
USRE40565E1 (en) 1997-08-01 2008-11-11 Societe Degremont Method and device for purifying waste water comprising an additional sludge treatment by ozonation
FR2766813A1 (fr) * 1997-08-01 1999-02-05 Degremont Procede et dispositif d'epuration d'eaux usees comprenant un traitement additionnel des boues par ozonation
US6514411B2 (en) 1998-02-05 2003-02-04 Thermal Process Systems, Llc Process for controlling foam in a treatment reactor
US6203701B1 (en) 1998-02-05 2001-03-20 Thermal Process Systems, Llc Process and apparatus for treating biosolids from wastewater treatment
US6168717B1 (en) 1998-02-05 2001-01-02 Thermal Process Systems, Llc Process for controlling foam in a treatment reactor
US6719903B1 (en) 1998-02-05 2004-04-13 Thermal Process Systems, Llc Process and apparatus for treating biosolids from wastewater treatment
US5948261A (en) * 1998-02-05 1999-09-07 Pressley; Richard L. Process for treating biosolids from wastewater treatment
US7708885B2 (en) 2001-05-31 2010-05-04 Biothane Llc Anaerobic digestion apparatus, methods for anaerobic digestion and for minimizing the use of inhibitory polymers in digestion
EP1544171A1 (fr) * 2003-12-17 2005-06-22 L'air Liquide S.A. Procédé de réduction de boues issues du traitement d'eaux usées par oxygénation et action mécanique
FR2864069A1 (fr) * 2003-12-17 2005-06-24 Air Liquide Procede de reduction de boues issues du traitement d'eaux usees par oxygenation et action mecanique
US7147780B2 (en) 2003-12-17 2006-12-12 L'Air Liquide, Société Anonyme à Directoire et Conseil de Surveillance pour l'Étude et l'Exploitation des Procédés Georges Claude Process for reducing sludge derived from the treatment of wastewater by oxygenation and mechanical action
CN107034142A (zh) * 2008-11-28 2017-08-11 泰拉瑞亚控股公司 在异养型微生物中制备特制油

Also Published As

Publication number Publication date
AU1071895A (en) 1995-06-06
GB2298195A (en) 1996-08-28
GB9323870D0 (en) 1994-01-05
GB9609460D0 (en) 1996-07-10
GB2298195B (en) 1997-07-30

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