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
  • C02F3/30—Aerobic and anaerobic processes
  • C02F3/301—Aerobic and anaerobic treatment in the same reactor
• • 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
  • C02F3/1236—Particular type of activated sludge installations
  • C02F3/1263—Sequencing batch reactors [SBR]
• • 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
  • C02F3/30—Aerobic and anaerobic processes
  • C02F3/308—Biological phosphorus removal
• • 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 field of the invention is that of the biological treatment of wastewater containing organic matter.
• the invention relates to a sequenced biological water treatment technique using biomass granules.
• the carbon and nitrogen pollution contained in the water, especially wastewater, is commonly reduced by the implementation of biological treatments, for example sequenced type.
• Sequenced biological water treatments consist of treating a volume of water by contacting it, in successive portions, with biomass housed in a reactor. This type of reactor is called SBR for Sequenced Batch Reactor in English.
• Biomass degrades carbon pollution during an aerobic phase. Ammonia is converted to nitrates during this aerobic phase by nitrification while nitrates are degraded to nitrogen during an anoxic phase of denitrification.
• Treated water, depleted in carbon and nitrogen pollution, can then be collected after being separated from the biomass.
• the treated water is generally separated from the bio mass involved in its treatment during a settling phase.
• the biomass is in water mainly in the form of small, slightly settling particles generally having a diameter of less than one millimeter. As a result, their settling is slow, which implies that the time required for the biological treatment of the water is relatively long.
• EP-B1-1 542 932 describes a technique of this type.
• a bed of biomass granules is housed in a reactor.
• the water to be treated is introduced at the base of the reactor during an anaerobic feeding.
• the reactor water supply rate is chosen such that the feed is slow. This prevents the formation of a fluidized bed of biomass granules.
• a non-agitated lag phase is observed in the reactor during which the water to be treated is left in contact with the biomass granules.
• the nutrients present in the water are assimilated by the bio mass whose granules have their volume and density increase accordingly.
• Oxygen is then introduced into the reactor by means of a ramp provided in its lower part.
• the nitrogen pollution contained in the water to be treated is then degraded at least in part by nitrification-denitrification.
• the granules are then extracted and a settling is carried out in the reactor before extracting treated water depleted in nitrogen pollution.
• the water supply to the reactor is slow to avoid fluidization of the bed of granules.
• the closer the granules are to the surface of the bed the lower their contact with the organic matter of the water to be treated on which they feed.
• There is therefore a vertical gradient of concentration of organic matter in the granules of the bed and therefore a non-uniform development of the granules.
• the feeding step is followed by a latency step during which the reactor contents are not stirred.
• the water to be treated is then kept in contact with the biomass granules long enough to allow the granules in the upper layers of the bed to absorb nutrients and develop in volume and density.
• the biomass of which the granules are constituted comprises in particular two types of microorganisms:
• GAO for "accumulative glucose organism” in English
• PAOs for "accumulative polyphosphate organism”
• the PAOs which are located in the lower layers of the granule bed are extracted from the reactor in greater proportions than the GAO.
• WAGs compete with ODPs and predominate within the reactor. This phenomenon has a negative impact on the level of phosphorus removal contained in the water to be treated subsequently introduced into the reactor.
• the water contained in the reactor further comprises granules, more weakly settling particles. These are removed with the treated water extracted from the reactor. It is then necessary to implement a polishing treatment downstream of the reactor. This tends to increase the size of water treatment facilities as well as the cost of water treatment.
• the invention particularly aims to overcome these disadvantages of the prior art.
• an object of the invention is to provide a biological water treatment technique which helps to improve the formation of biomass granules.
• an object of the invention is to provide, in at least one embodiment, such a technique that allows the formation of granules of solid and stable biomasses.
• Another objective of the invention is to provide, in at least one embodiment, such a technique which makes it possible to improve the settlability of the biomass granules.
• the invention also aims to provide, in at least one embodiment, such a technique that reduces the duration of the biological treatment of water.
• the invention further aims to provide, in at least one embodiment, such a technique that maximizes the elimination of pollution contained in the water to be treated.
• the invention also aims to provide, in at least one embodiment, such a technique that is versatile including that it can ensure the treatment of different volumes of water with varying pollutants.
• Another object of the invention is to provide, in at least one embodiment, such a technique that is simple to implement and / or reliable and / or economic.
• such a method comprises a plurality of successive cycles each comprising:
• the invention is based on a completely novel approach according to which a water to be treated is rapidly introduced inside a reactor in which it is brought into contact with biomass granules under anaerobic atmosphere, and then phases successive anaerobic brewing of the reactor contents, aeration, rapid decantation and extraction of treated water are implemented.
• a water to be treated is rapidly introduced inside a reactor in which it is brought into contact with biomass granules under anaerobic atmosphere, and then phases successive anaerobic brewing of the reactor contents, aeration, rapid decantation and extraction of treated water are implemented.
• all the granules of the bed formed in the reactor is promptly brought into contact with the water to be treated.
• the granules are then distributed substantially uniformly and without stratification inside the reactor.
• the agitation generated within the reactor makes it possible to increase the exposure of the entire surface of each granule to the nutrients contained in the water to be treated.
• the mixing of the granules inside the reactor makes it possible, during the feeding phase, to improve the exchanges between the water and the granules. As a result, the rate of assimilation by the granules of nutrients initially present in the water, which is not limited by diffusion, is increased.
• the granules formed then have a larger volume and density than those obtained by the implementation of the technique according to the prior art.
• the diameter of these granules is generally between 1 and 5 millimeters while their density is generally between 1.02 and 1.10 kg / 1.
• the granules formed then have a good ability to decant.
• the technique according to the invention leads to promote the development of granules in proportions such that its implementation reduces the minimum concentration of organic matter that the water to be treated must contain to allow the formation of solid granules highly decantable.
• the technique according to the invention makes it possible to generate the formation of highly settling solid granules from a water whose minimum concentration of organic matter is of the order of 400 mg / l.
• the technique according to the invention makes it possible to increase the exchanges between the water to be treated and the granules, its implementation leads to improving the reduction of the organic matter contained in the water to be treated.
• the technique according to the invention can therefore be implemented to effectively treat water with an organic matter concentration greater than 1500 mg / l.
• the water supply speed of said reactor during said feeding step is between 10 and 20 m / h or m 3 / m 2 / h. This speed will preferably be greater than 8 mh or m 3 / m 2 / h.
• the speed of supply of water can indifferently be expressed in m / h or in m 3 / m 2 / h.
• the m 3 correspond to a volume of water while the m 2 correspond to the surface of the reactor.
• said anaerobic stirring step comprises a recirculation of at least a portion of the water contained in said reactor from one zone of said reactor to another.
• This implementation makes it possible to generate inside the reactor agitation sufficiently important to promote the development of large, solid and dense biomass granules, and low enough to maintain the integrity of the granules.
• the recirculation speed will be between 4 and 8 m / h.
• said anaerobic stirring step comprises mixing the contents of said reactor by means of stirrers.
• Such an implementation makes it possible to generate an adequate mixing of the contents of the reactor in a simple and effective manner.
• the level of agitation inside said reactor during said anaerobic feeding step is between 3 and 30 W / m 3 .
• the level of agitation inside said reactor during said anaerobic stirring step is between 5 and 10 W / m 3 .
• Such stirring levels within the reactor promote the development of bulky, solid and dense granules while preserving their integrity.
• the level of the point of discharge of the water during said step of discharging treated water depleted in organic matter is variable.
• This implementation also makes it possible to bring the level of the point of extraction of water closer to the bed of granules present at the bottom of the reactor and to evacuate the weakly settling particles which accumulate over time on the surface of the upper layers of water. granules of the bed.
• This implementation can also lead to authorizing the development of a bed of granules more or less thick at the bottom of the reactor so as to allow the treatment of water with levels of polluting loads higher or lower.
• the level of the water extraction point can also be considerably closer to the surface of the bed of granules present at the bottom of the reactor. In this way, almost all of the treated water depleted in organic matter can be extracted from the reactor.
• the concentration of organic matter in the reactor is thus increased with each new feed by limiting the dilution of the water to be treated with stagnant treated water in the reactor after extraction. The growth of the granules is thus promoted because they feed on the organic matter to develop.
• a method according to the invention comprises a step of extracting granules, said extraction step being preferably implemented after the course of several successive cycles.
• Said extraction step is preferably preceded by a stirring step of said reactor.
• the biomass of which the granules are constituted includes microorganisms called GAO ("Glucose Accumulative Organisms") and microorganisms called PAO ("Polyphosphate accumulative organisms").
• GAOs which assimilate glucose, are less dense than PAOs that assimilate phosphorus.
• PAO Polyphosphate accumulative organisms
• said stirring step preferably comprises a step of aeration of said reactor.
• Aeration of the reactor before extracting granules not only creates agitation, but also maintains an aerobic atmosphere and prevents the phosphorus assimilated by the granules from escaping from it. distribute in the reactor before the granules are extracted. This implementation therefore makes it possible to improve the removal of phosphorus.
• At least one of said cycles comprises a step of extraction of weakly settling particles, said weakly settling particles not being extracted with said treated water.
• the extracted treated water is thus separated from the slightly settling particles so that the treated water has a sufficiently low level of solid particles in suspension to prevent the implementation of a downstream polishing treatment. Only the slightly settling particles extracted can be routed to a treatment of this type. This limits the cost of producing biologically treated water.
• FIG. 1 illustrates a first example of a water treatment installation for the implementation of a method according to the invention
• FIG. 2 illustrates a second example of a water treatment installation for the implementation of a method according to the invention.
• the general principle of the invention consists in treating a water biologically by introducing it rapidly during an anaerobic feeding phase inside a reactor in which it is brought into contact with biomass granules. .
• the water then undergoes successive anaerobic phases of mixing of the reactor contents, aeration, and then rapid settling.
• a treated water is finally extracted from the reactor.
• such an installation comprises a water supply pipe to be treated 10 whose outlet is connected to the inlet of a "T" connector 12.
• a valve 11 is mounted on the pipe 10.
• the "T” connector 12 comprises an outlet which is connected to the inlet of a recirculation pump 13.
• the "T” connector 12 comprises a second inlet which is connected to the outlet of a recirculation duct 14 on which is mounted a valve 27.
• the output of the recirculation pump 13 is connected to a collector 15 which opens at the bottom of a biological reactor 16.
• the biological reactor 16 comprises a bottom 161, an upper part 162 and a side wall 163.
• the side wall 163 is traversed by an extraction mouth 17.
• the reactor 16 houses means for extracting treated water and / or particles. These extraction means comprise a pipe 18.
• the inlet 181 of this pipe 18 is provided with a float 29.
• the outlet 182 of this pipe 18 is connected to the extraction mouth 17.
• the extraction mouth 17 is connected to a "T" connector 19, a first outlet of which is connected to a treated water discharge pipe 20 on which a valve 21 is mounted, and a second outlet is connected to a pipe discharge of loosely settling particles and granules 22 on which a valve 23 is mounted.
• the installation comprises aeration means of the reactor 16.
• These aeration means comprise an air supply pipe 24 whose outlet is connected to a diffuser 25 housed at the bottom 161 of the reactor 16.
• the reactor 16 houses a bed consisting of a plurality of biomass granules
• the recirculation pipe 14 comprises an inlet 141 which is connected to a funnel 28 placed in the upper part 162 of the reactor 16. In a variant, this recirculation could be carried out using the treated water discharge pipe 20.
• Figure 2 illustrates a variant of the water treatment plant illustrated in Figure 1.
• the water recirculation means which notably comprise the funnel 28 and the recirculation duct 14, are replaced in this variant by paddle stirrers 200 housed inside the reactor 16.
• the biological reactor 16 operates, as will be explained more in detail later, in sequenced mode. It is therefore a type of reactor SBR for "Sequenced Batch Reactor" in English in which the total volume of water to be treated is treated in successive portions.
• a method according to the invention comprises a plurality of successive cycles each comprising:
• valve 11 is open while the valves 27, 21 and 23 are closed.
• the pump 13 is implemented in such a way that water to be treated is introduced into the reactor 16 from its bottom 161 via the supply pipe 10, the collector 15 and the pipes 151 preferably until the high level of the reactor 16 is reached.
• the water supply speed of the reactor 16 during the feeding stage is between 10 and 20 m / h.
• the water supply to be treated reactor is therefore fast.
• the water to be treated rapidly passes through the bed of granules present at the bottom of the reactor 16 so that it is fluidized. Thus, all the granules constituting the bed is exposed rapidly to the water to be treated on their entire surface. As soon as the water supply to the reactor is maximized, the exchanges between the water to be treated and the bio mass of which the granules are formed are thus maximized. In other words, as soon as the reactor feeds, the granules begin to assimilate nutrients.
• agitation within the reactor 16 is generated by the implementation of stirring means.
• valve 1 1 is closed, the valve 27 is open and the pump 13 is implemented so that water contained in the reactor 16 is sucked into the funnel 28 located in the upper portion 162 of the reactor 16 and flows into the recirculation pipe 14 before being reinjected into the bottom 161 of the reactor 16 via the collector 15 and the pipes 151.
• the water recirculation speed is between 4 and 8 m / h.
• stirring is generated in the reactor 16 by rotating the paddle stirrers 200.
• stirring means during the anaerobic stirring stage makes it possible to create a level of agitation inside the reactor of between 5 and 10 W / m 3 .
• Such a level of agitation improves the exchanges between the water to be treated and the biomass granules while preserving their integrity.
• the implementation of the technique according to the invention which promotes the development of granules, leads to the production of stable granules, that is to say solids, having a high density and volume and therefore a good ability to decant.
• the diameter of the granules thus obtained is generally between 1 and 5 millimeters whereas their density is generally between 1.03 and 1.5. kg / 1.
• the technique according to the invention also improves the reduction of nutrients, in particular phosphorus and nitrogen.
• the valve 27 is then closed, the pump 13 stopped and air, or another gas containing oxygen, is introduced into the bottom of the reactor 16 via the pipe 24 and the diffuser 25.
• concentration of dissolved oxygen in the reactor is generally between 1 and 4 mg 0 2 / l.
• Part of the bacteria that make up the biomass that make up the granules converts the ammonia present in the water into nitrates by consuming oxygen. Nitrification of the water is then observed.
• the oxygen concentration inside the granules decreases in depth.
• the oxygen concentration at the heart of the granules is substantially zero.
• the granules formed in the reactor 16 decant rapidly because of their size. During the settling phase, the highly settling granules accumulate at the bottom of the reactor 16.
• the treated water depleted in organic matter, as well as in nutrients, can then be extracted from the reactor 16.
• the valve 21 is open so that the treated water flows from the inlet 181 of the pipe 18 floating on the surface of the water. Given that the inlet 181 of the pipe 18 floats on the surface of the water, it is possible to trigger the extraction of the treated water through the opening of the valve 21 without waiting for all the granules has decanted at the bottom of the reactor 16.
• the extraction rate of the treated water can thus be chosen so that the drop in the level of the water in the reactor follows the drop in the level of the granules in the reactor. It is thus possible to reduce the time of production of treated water.
• the extraction rate of the water will preferably be between 10 and 20 m / h.
• the level of the extraction point of the treated water in other words that of the inlet 181 of the pipe 18, is variable, and decreases in this case during the extraction. It is thus possible to lower the level of the inlet 181 of the pipe 18 until it reaches a level close to that of the surface of the bed of granules. This allows the extraction of a very large volume of treated water and consequently reduces the volume of treated water stagnant inside the reactor 16 after the extraction step is completed.
• the water contained in the reactor additionally comprises highly settling granules of other more weakly settling particles. During the settling phase, these particles tend to accumulate to form a layer on the surface of the bed of granules located at the bottom of the reactor 16.
• the valve 21 can be closed and the valve 23 opened so that the Low settling particles can be removed from the reactor 16 separately from the treated water.
• the treated water extracted from the reactor 16 thus has a low level of solid particles in suspension, which prevents the implementation of a downstream polishing treatment.
• the low settling particles extracted from the reactor 16 can be sent for further processing. Such a step of extraction of weakly settling particles may not be implemented at each cycle.
• a new cycle can be initiated by implementing a new anaerobic step 16. As many cycles as necessary will be implemented to ensure the treatment of a given volume of water to be treated.
• a method according to the invention may comprise one or more granule extraction steps. This or these granule extraction steps are preferably implemented after the course of several successive cycles.
• the extraction of granules can be obtained at the end of a low-decantable particle extraction step leaving the valve 23 open.
• the step of extracting granules is preceded by a step of stirring the contents of the reactor 16.
• This stirring could be generated mechanically by means of stirrers. It is preferentially generated by venting the inside of the reactor via the pipe 24 and the diffuser 25.
• the bed of granules is stirred so that the distribution of GAO and PAO contained in the granules is substantially homogeneous inside the bed.
• the proportions of GAO and PAO discharged out of the reactor 16 are substantially identical. In this way, GAOs are not preponderant inside the reactor at the following cycles, which would limit the reduction of phosphorus.
• Aeration of the bed before the extraction of granules also makes it possible to maintain an aerobic state inside the reactor 16 and to prevent a portion of the phosphorus assimilated by the granules being discharged into the reactor before the granules are discharged. . This contributes to improving phosphorus abatement.
• the duration of the step is the duration of the step:
• anaerobic feeding is equal to 15 minutes and is preferably between 10 and 30 minutes;
• anaerobic agitation is 45 minutes and is preferably between 30 and 60 minutes;
• aeration time is equal to 120 minutes and is preferably between 90 and 180 minutes;
• Decantation is equal to 15 minutes and is preferably included between 10 and 30 minutes;
• treated water extraction is equal to 15 minutes and is preferably between 10 and 30 minutes.
• aeration is equal to 2 hours
• Treated water extraction is equal to 1 hour.
• aeration is 2 hours
• decantation is equal to 2-10 minutes
• Treated water extraction is equal to 2 -10 minutes
• the implementation of the technique according to the invention thus makes it possible to reduce the duration of the duration of the treatment.

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

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• 2011
  • 2011-06-22 FR FR1155482A patent/FR2976937B1/fr not_active Expired - Fee Related
• 2012
  • 2012-06-19 WO PCT/EP2012/061694 patent/WO2012175489A1/fr active Application Filing
  • 2012-06-19 MX MX2013015425A patent/MX2013015425A/es not_active Application Discontinuation
  • 2012-06-19 CN CN201280030325.3A patent/CN103619762A/zh active Pending
  • 2012-06-19 AU AU2012274193A patent/AU2012274193A1/en not_active Abandoned
  • 2012-06-19 US US14/127,992 patent/US20140224729A1/en not_active Abandoned
  • 2012-06-19 EP EP12727882.8A patent/EP2723692A1/fr not_active Withdrawn
  • 2012-06-19 CA CA 2837884 patent/CA2837884A1/en not_active Abandoned
  • 2012-06-19 BR BR112013032892A patent/BR112013032892A2/pt not_active IP Right Cessation
• 2013
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