WO1999037586A2 - Process for oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water - Google Patents

Process for oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water Download PDF

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Publication number
WO1999037586A2
WO1999037586A2 PCT/BE1999/000009 BE9900009W WO9937586A2 WO 1999037586 A2 WO1999037586 A2 WO 1999037586A2 BE 9900009 W BE9900009 W BE 9900009W WO 9937586 A2 WO9937586 A2 WO 9937586A2
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WO
WIPO (PCT)
Prior art keywords
contaminated water
bacteria
colonised
mixture
process according
Prior art date
Application number
PCT/BE1999/000009
Other languages
French (fr)
Other versions
WO1999037586A3 (en
Inventor
Joost Desmet
Rikie Seynaeve
Johan Craeye
Original Assignee
Desotec N.V.
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 Desotec N.V. filed Critical Desotec N.V.
Publication of WO1999037586A2 publication Critical patent/WO1999037586A2/en
Publication of WO1999037586A3 publication Critical patent/WO1999037586A3/en

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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
    • C02F3/1289—Aeration by saturation under super-atmospheric pressure
    • 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
    • C02F3/04—Aerobic processes using trickle filters
    • 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
    • C02F3/10—Packings; Fillings; Grids
    • 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
    • C02F3/26—Activated sludge processes using pure oxygen or oxygen-rich gas
    • 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 a novel process for the oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water, wherein a mixture of contaminated water and part of the process effluent is saturated with oxygen containing gas and subsequently circulated over a bed of the support colonised with bacteria.
  • Biological treatment is a useful method for the decomposition of organic compounds in contaminated water like groundwater or aqueous waste streams originating from agriculture or industry.
  • the bacteria which are effective for the biological treatment may be used in free suspension, or alternatively immobilised on solid supports.
  • the use of solid supports have the advantage to reduce both the bacteria washout in flow systems and sludge formation, which latter may hamper the process flow.
  • the solid supports are usually packed as a stationary bed in a reactor system and the contaminated water is allowed to percolate through the bed, during which the biological decomposition of the organic compounds present in the contaminated water takes place.
  • Biological processes known in the art have the disadvantages that the trough-put of the reactor system is usually too low to allow an almost complete decomposition of the organic compounds present in the contaminated water, that the dimensions of the reactor system are usually very large and that the support colonised with bacteria requires frequent regeneration by aeration.
  • the trough-put of such a reactor system depends, as a matter of fact, upon the organic compounds load of the contaminated water, upon the acceptable level of residual organic compounds present in the process effluent and finally, upon the dimensions and the efficiency of the reactor system.
  • neither the load of the contaminated water, nor the level of residual organic compounds present in the process effluent are variables as they are determined by the origin of the contaminated water and/or by the destination of the process effluent.
  • the extend of decomposition of the organic compounds present in contaminated water in the reactor system is determined by the process trough-put, but above all by amount of oxygen that is readily available for the aerobic biological process.
  • Oxygen is usually supplied to the reactor system as a stream of air blown through the bed of support colonised with bacteria together with the contaminated water, but the efficiency of the adsorption of oxygen by the bacteria and/or the solid support from this stream of air is rather low and, therefore, the availability of the oxygen for the biological process and the efficiency of the biological process are on the low side.
  • the bed of support colonised with bacteria needs frequent regeneration.
  • the support colonised with bacteria in the reactor system as well as the bacteria need to be saturated with oxygen or, in other words, as much oxygen as is virtually possible is allowed into the reactor system to provide for a readily available reservoir of oxygen for the subsequent biological process. Once the efficiency of the biological process has dropped below the acceptable level, the biological process is to be shut down and the reactor system regenerated again.
  • the object of the present invention to provide for a process to biologically treat contaminated water, which process does not require frequent regeneration and in which process oxygen is readily available for an almost complete decomposition of organic compounds present in the contaminated water.
  • the present invention relates to a new process for the oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water, wherein a mixture of contaminated water and part of the process effluent is saturated with oxygen containing gas and subsequently circulated over a bed of the support colonised with bacteria.
  • a reactor system for the biological decomposition of organics present in contaminated water can be kept constant at a very high level over several months to a couple of years, by 1 ) levelling the organic compounds load of the contaminated water and 2) intimately mixing oxygen into the water stream fed to the reactor system, thus saturating this stream with oxygen.
  • the saturation of the mixture of contaminated water and part of the process effluent and, as a result, the biological process has also surprisingly been found to be even much more effective when this mixture is pressurised prior to the saturation with oxygen.
  • the pressurised and oxygen saturated mixture of contaminated water and part of the process effluent is then kept under a substantially constant pressure when it is being circulated of the support material colonised with bacteria in the reactor system.
  • Oxygen in this pressurised and saturated mixture is present in a much higher quantity and is much more available for the biological decomposition of the organic compounds present in the reactor system than is known from the processes currently available in the art.
  • the oxygen is dissolved into the pressurised mixture and therefore much more available for both the support material and the bacteria present in the reactor system.
  • the flow of the process according to the present invention is figuratively illustrated in figure 1.
  • the contaminated water is fed to a vessel (1) in which the process effluent is also collected.
  • a determined mixture of contaminated water and process effluent is brought under pressure and pumped by means of the pump (2) into the saturation unit (3).
  • oxygen is intimately dispersed into the pressurised mixture of contaminated water and process effluent, whereupon the oxygen saturated and pressurised mixture of contaminated water and process effluent is fed into the reactor system (4).
  • the mixture is allowed to percolate through the support colonised with bacteria in the reactor system (4) and then fed back to the vessel (1 ) where, at the process outlet (5) the biologically treated mixture, or process effluent, is brought back to atmospherical pressure. Water of an acceptable level of organic compounds load is then drawn off of the process according to the invention at the effluent overflow (6) of vessel (1).
  • the pump (2) of the process according to the present invention should preferably allow to bring the mixture of contaminated water and part of the process effluent to a pressure of 1 to 10 bars above atmospherical pressure.
  • a pump is used that allows a pressure increase from 1 to 3 bars above atmospherical pressure as we have found that pressures above 3 bars above atmospherical pressure do not significantly increase the process efficiency and justify the higher costs of a pump which can achieve pressures up to 10 bars.
  • all fittings, including the saturation unit (3) and the reactor system (4) should be dimensioned as to allow the pumping pressure of pump (2). Fittings, a saturation unit (3) and a reactor system (4) that can withstand pressures up to 10 bars above atmospherical pressure are rather expensive.
  • oxygen - or air for instance - is intimately dispersed into the pressurised mixture of contaminated water and part of the process effluent.
  • the support colonised with bacteria in the reactor system may be selected from the group consisting of activated carbon containing material, activated carbon, lignite, zeolites, glass, sand and synthetic material. Preferably however, the support colonised with bacteria is activated carbon.
  • the activated carbon also acts as an adsorbent and as a catalyst for the chemical oxidation of these organic compounds. It has also been found that the effect of the combination of the biological oxidation by the bacteria and the chemical oxidation catalysed by the activated carbon is substantially higher than the aggregated effects of both oxidation treatments carried out separately.
  • An additional advantage of the process according to the present invention is that, when the support material colonised with bacteria is activated carbon, the biological oxidation by the bacteria of the organic compounds adsorbed on the activated carbon surface substantially increases the efficiency of the chemical oxidation catalysed by the activated carbon, as well as the life span of the activated carbon itself.
  • Example 1 (cf. figure 1 )
  • This system is installed to treat the physic-chemical and biological pre- treated wastewater from a tank- and truck cleaning company.
  • the water contains nutrients (N and P), some oil and detergents.
  • the activated carbon filter (4) contains 15m 3 activated carbon and the pump (2) circulates the water at an average of 50m 3 /h.
  • the average pressure on the activated carbon filter (4) is 3 bar.
  • the circulationwater is saturated under pressure (3,5 bar) with compressed air in a special saturation-unit (3). 4m 3 /h air at 4 bar is needed. After passing through the filter the circulationwater returns (5) to a collector-vessel (1).
  • This vessel is needed to 1 ) if necessary, back-wash the filter and to 2) degas the circulationwater.
  • the activated carbon could be used for 8 months before exhaustion of the carbon and nitrogen (in organic form and ammoniac) was converted to nitrate.
  • This system is also installed as a pilot-plant to treat the physic-chemical and biological pre-treated wastewater from a chemical company.
  • the activated carbon filter contained 1 m 3 activated carbon and a pump circulated the water at an average of 5m 3 /h.
  • the average pressure on the activated carbon filter was 3 bar.
  • the circulationwater was saturated under pressure (3,5 bar) with compressed air in a special saturation-unit with 0,5m 3 /h air at 4 bar.

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  • Life Sciences & Earth Sciences (AREA)
  • Biodiversity & Conservation Biology (AREA)
  • Microbiology (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Biological Treatment Of Waste Water (AREA)
  • Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)

Abstract

The present invention is directed to a novel process for the oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water. The present invention is directed, in particular, to a method to simultaneously regenerate supports colonised with bacteria and to biologically treat contaminated water, wherein a mixture of the contaminated water and part of the process effluent is saturated with oxygen containing gas and subsequently circulated over a bed of the support colonised with bacteria.

Description

Process for oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water
Background of the invention
The present invention relates to a novel process for the oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water, wherein a mixture of contaminated water and part of the process effluent is saturated with oxygen containing gas and subsequently circulated over a bed of the support colonised with bacteria.
Biological treatment is a useful method for the decomposition of organic compounds in contaminated water like groundwater or aqueous waste streams originating from agriculture or industry. The bacteria which are effective for the biological treatment may be used in free suspension, or alternatively immobilised on solid supports. The use of solid supports have the advantage to reduce both the bacteria washout in flow systems and sludge formation, which latter may hamper the process flow. The solid supports are usually packed as a stationary bed in a reactor system and the contaminated water is allowed to percolate through the bed, during which the biological decomposition of the organic compounds present in the contaminated water takes place.
Biological processes known in the art have the disadvantages that the trough-put of the reactor system is usually too low to allow an almost complete decomposition of the organic compounds present in the contaminated water, that the dimensions of the reactor system are usually very large and that the support colonised with bacteria requires frequent regeneration by aeration. The trough-put of such a reactor system depends, as a matter of fact, upon the organic compounds load of the contaminated water, upon the acceptable level of residual organic compounds present in the process effluent and finally, upon the dimensions and the efficiency of the reactor system. However, neither the load of the contaminated water, nor the level of residual organic compounds present in the process effluent are variables as they are determined by the origin of the contaminated water and/or by the destination of the process effluent. The extend of decomposition of the organic compounds present in contaminated water in the reactor system is determined by the process trough-put, but above all by amount of oxygen that is readily available for the aerobic biological process. Oxygen is usually supplied to the reactor system as a stream of air blown through the bed of support colonised with bacteria together with the contaminated water, but the efficiency of the adsorption of oxygen by the bacteria and/or the solid support from this stream of air is rather low and, therefore, the availability of the oxygen for the biological process and the efficiency of the biological process are on the low side. To increase the efficiency of the biological process, the bed of support colonised with bacteria needs frequent regeneration. The support colonised with bacteria in the reactor system as well as the bacteria need to be saturated with oxygen or, in other words, as much oxygen as is virtually possible is allowed into the reactor system to provide for a readily available reservoir of oxygen for the subsequent biological process. Once the efficiency of the biological process has dropped below the acceptable level, the biological process is to be shut down and the reactor system regenerated again.
When the efficiency of the biological process is on the low side, the organic compounds present in the contaminated water accumulate in the reactor system and tend to make the support material useless and poison the bacteria. At a certain level of organic compounds load on the support material, the reactor system cannot be regenerated again and the support colonised with bacteria needs to be replaced by a new charge.
Objects of the invention
It is therefore, the object of the present invention to provide for a process to biologically treat contaminated water, which process does not require frequent regeneration and in which process oxygen is readily available for an almost complete decomposition of organic compounds present in the contaminated water.
It is also an object of the present invention to provide for a process to biologically treat contaminated water, which process has a higher trough-put capacity for a given reactor system volume, a reactor system of substantially reduced dimensions for a given trough-put capacity and organic load and a substantially higher efficiency through the availability of the oxygen required for the biological decomposition of the organics present in the contaminated water. These, and other objectives and advantages of the present invention, will be come apparent as the description of the present invention proceeds.
Detailed description of the invention The present invention relates to a new process for the oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water, wherein a mixture of contaminated water and part of the process effluent is saturated with oxygen containing gas and subsequently circulated over a bed of the support colonised with bacteria. We have surprisingly found that the efficiency of a reactor system for the biological decomposition of organics present in contaminated water can be kept constant at a very high level over several months to a couple of years, by 1 ) levelling the organic compounds load of the contaminated water and 2) intimately mixing oxygen into the water stream fed to the reactor system, thus saturating this stream with oxygen.
We have also found that the levelling of the organic compounds load of the contaminated water by dilution with process effluent significantly increases biological decomposition efficiency and process stability, especially when the organic compounds load of the contaminated water is either too high or too much fluctuating.
The saturation of the mixture of contaminated water and part of the process effluent and, as a result, the biological process has also surprisingly been found to be even much more effective when this mixture is pressurised prior to the saturation with oxygen. The pressurised and oxygen saturated mixture of contaminated water and part of the process effluent is then kept under a substantially constant pressure when it is being circulated of the support material colonised with bacteria in the reactor system.
Oxygen in this pressurised and saturated mixture is present in a much higher quantity and is much more available for the biological decomposition of the organic compounds present in the reactor system than is known from the processes currently available in the art. As a matter of fact, because of the pressure, the oxygen is dissolved into the pressurised mixture and therefore much more available for both the support material and the bacteria present in the reactor system.
The flow of the process according to the present invention is figuratively illustrated in figure 1. The contaminated water is fed to a vessel (1) in which the process effluent is also collected. A determined mixture of contaminated water and process effluent is brought under pressure and pumped by means of the pump (2) into the saturation unit (3). In this saturation unit, oxygen is intimately dispersed into the pressurised mixture of contaminated water and process effluent, whereupon the oxygen saturated and pressurised mixture of contaminated water and process effluent is fed into the reactor system (4).
The mixture is allowed to percolate through the support colonised with bacteria in the reactor system (4) and then fed back to the vessel (1 ) where, at the process outlet (5) the biologically treated mixture, or process effluent, is brought back to atmospherical pressure. Water of an acceptable level of organic compounds load is then drawn off of the process according to the invention at the effluent overflow (6) of vessel (1).
The pump (2) of the process according to the present invention should preferably allow to bring the mixture of contaminated water and part of the process effluent to a pressure of 1 to 10 bars above atmospherical pressure. Preferably, a pump is used that allows a pressure increase from 1 to 3 bars above atmospherical pressure as we have found that pressures above 3 bars above atmospherical pressure do not significantly increase the process efficiency and justify the higher costs of a pump which can achieve pressures up to 10 bars. Additionally, all fittings, including the saturation unit (3) and the reactor system (4), should be dimensioned as to allow the pumping pressure of pump (2). Fittings, a saturation unit (3) and a reactor system (4) that can withstand pressures up to 10 bars above atmospherical pressure are rather expensive. In the saturation unit (3), oxygen - or air for instance - is intimately dispersed into the pressurised mixture of contaminated water and part of the process effluent.
Pressures of from 1 to 10 bars above atmospherical pressure are found to allow an oxygen load of the mixture of contaminated water and part of the process effluent in the saturation unit (3) of from 10 to about 100 mg. O2 per litre of pressurised mixture; pressures of from 1 to 3 bars above atmospherical pressure are found to allow from 10 to 40 mg. O2 per litre of pressurised mixture. The support colonised with bacteria in the reactor system may be selected from the group consisting of activated carbon containing material, activated carbon, lignite, zeolites, glass, sand and synthetic material. Preferably however, the support colonised with bacteria is activated carbon. As a matter of fact, apart from the biological decomposition of the organic compounds present in the contaminated water by the bacteria, the activated carbon also acts as an adsorbent and as a catalyst for the chemical oxidation of these organic compounds. It has also been found that the effect of the combination of the biological oxidation by the bacteria and the chemical oxidation catalysed by the activated carbon is substantially higher than the aggregated effects of both oxidation treatments carried out separately.
An additional advantage of the process according to the present invention is that, when the support material colonised with bacteria is activated carbon, the biological oxidation by the bacteria of the organic compounds adsorbed on the activated carbon surface substantially increases the efficiency of the chemical oxidation catalysed by the activated carbon, as well as the life span of the activated carbon itself. Example 1 (cf. figure 1 )
This system is installed to treat the physic-chemical and biological pre- treated wastewater from a tank- and truck cleaning company.
The daily volume wastewater to treat is 70m3/day (=3m3/hour), with an average COD-value of 500 mg/l and an average BOD-value of <15 mg/l.
The water contains nutrients (N and P), some oil and detergents.
Sometimes the amount of organic nitrogen and ammoniac was more than
60 mg/l.
The activated carbon filter (4) contains 15m3 activated carbon and the pump (2) circulates the water at an average of 50m3/h. The average pressure on the activated carbon filter (4) is 3 bar.
The circulationwater is saturated under pressure (3,5 bar) with compressed air in a special saturation-unit (3). 4m3/h air at 4 bar is needed. After passing through the filter the circulationwater returns (5) to a collector-vessel (1).
This vessel is needed to 1 ) if necessary, back-wash the filter and to 2) degas the circulationwater.
Through the overflow (6) in the vessel, the treated water is evacuated. In this situation there is a load of 1 ,4kg COD removed/rrrVday.
Normally, without the aeration of the carbon every 3 month the activated carbon had to be replaced and no elimination of organic nitrogen or ammoniac was noticed.
With the aeration however, the activated carbon could be used for 8 months before exhaustion of the carbon and nitrogen (in organic form and ammoniac) was converted to nitrate.
The COD on the outlet contains average 200 mg/l. Example 2
This system is also installed as a pilot-plant to treat the physic-chemical and biological pre-treated wastewater from a chemical company.
The daily volume wastewater to treat was 2,4-3,6m3/day (=100-150 litres/hour), with an average COD-value of 540ppm and an average
BOD-value of <15ppm. The water contained nutrients (N and P) and the amount of suspended solids was average 200ppm.
The activated carbon filter contained 1 m3 activated carbon and a pump circulated the water at an average of 5m3/h. The average pressure on the activated carbon filter was 3 bar.
The circulationwater was saturated under pressure (3,5 bar) with compressed air in a special saturation-unit with 0,5m3/h air at 4 bar.
After passing through the filter the circulationwater returned to a collector-vessel, with overflow. In this situation there was a load of 1 ,3 up to 1 ,95 kg COD removed/m3/day.
During 6 months of testing, the unit did not saturate and did not block, even at the highest load. The outcoming COD was average 80 ppm and all the suspended solids were eliminated.

Claims

Claims
1. Process for the oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water, characterised in that a mixture of contaminated water and part of the process effluent is saturated with oxygen containing gas and subsequently circulated over a bed of the support colonised with bacteria.
2. Process according to claim 1 , characterised in that the mixture of contaminated water and part of the process effluent is pressurised prior to saturation with oxygen containing gas and circulation over the bed of the support colonised with bacteria.
3. Process according to claim 1, characterised in that the oxygen containing gas is air.
4. Process according to claim 2, characterised in that the mixture of contaminated water and part of the process effluent is pressurised to 1 to 10 bar above atmospheric pressure, preferably 1 to 3 bar above atmospheric pressure.
5. Process according to claim 2, characterised in that the pressurised mixture of contaminated water and part of the process effluent is saturated with oxygen containing gas to such an extend that the pressurised mixture contains from 10 to 100 mg O2/litre, preferably from 10 to 40 mg O2/litre.
6. Process according to claim 1 , characterised in that the support colonised with bacteria is selected from the group consisting of activated carbon containing material, activated carbon, lignite, zeolites, glass, sand and synthetic material.
7. Process according to claim 1 , characterised in that the support colonised with bacteria is activated carbon.
8. Process according to claim 1 , characterised in that the ratio aqueous waste stream over process effluent of the mixture ranges from 0.01 to 1, preferably from 0.02 to 0.2.
PCT/BE1999/000009 1998-01-26 1999-01-25 Process for oxidative regeneration of supports colonised with bacteria and used in the biological treatment of contaminated water WO1999037586A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP98101277 1998-01-26
EP98101277.6 1998-01-26

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WO1999037586A2 true WO1999037586A2 (en) 1999-07-29
WO1999037586A3 WO1999037586A3 (en) 1999-09-23

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6811702B2 (en) 2001-06-26 2004-11-02 Aquafin N.V. Process and installation for treating a polluted aqueous liquid showing a COD value

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772187A (en) * 1971-07-14 1973-11-13 D Othmer Sewage treatment process
US4163712A (en) * 1973-01-08 1979-08-07 Boc Limited Treatment of liquid
US4419243A (en) * 1977-10-20 1983-12-06 The University Of Manchester Institute Of Science And Technology Growth of biomass
US5538635A (en) * 1992-11-06 1996-07-23 Envirex, Inc. Method for dissolving gas in liquid including pressurized bubble contactor in sidestream

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3772187A (en) * 1971-07-14 1973-11-13 D Othmer Sewage treatment process
US4163712A (en) * 1973-01-08 1979-08-07 Boc Limited Treatment of liquid
US4419243A (en) * 1977-10-20 1983-12-06 The University Of Manchester Institute Of Science And Technology Growth of biomass
US5538635A (en) * 1992-11-06 1996-07-23 Envirex, Inc. Method for dissolving gas in liquid including pressurized bubble contactor in sidestream

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6811702B2 (en) 2001-06-26 2004-11-02 Aquafin N.V. Process and installation for treating a polluted aqueous liquid showing a COD value

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