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
  • C02F3/006—Regulation methods for biological treatment
• • 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
  • C02F3/28—Anaerobic digestion processes
  • C02F3/2846—Anaerobic digestion processes using upflow anaerobic sludge blanket [UASB] reactors
• • 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
  • C02F3/28—Anaerobic digestion processes
  • C02F3/286—Anaerobic digestion processes including two or more steps
• • 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
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/001—Upstream control, i.e. monitoring for predictive control
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/02—Temperature
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/06—Controlling or monitoring parameters in water treatment pH
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/28—CH4
  • C02F2209/285—CH4 in the gas phase
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2301/00—General aspects of water treatment
  • C02F2301/10—Temperature conditions for biological treatment
  • C02F2301/103—Psychrophilic treatment
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2301/00—General aspects of water treatment
  • C02F2301/10—Temperature conditions for biological treatment
  • C02F2301/106—Thermophilic treatment
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2303/00—Specific treatment goals
  • C02F2303/10—Energy recovery
• • 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
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E50/00—Technologies for the production of fuel of non-fossil origin
  • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel
• • 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
  • Y02W10/30—Wastewater or sewage treatment systems using renewable energies

Definitions

• the field of the invention is that of the treatment of effluents with a view to their purification.
• the invention more specifically finds application particularly in the field of treatment of urban or industrial wastewater effluents.
• a technique commonly used to purify this type of effluent 10 consists, with reference to FIG. 1, in conveying it in pretreatment means 11.
• These pretreatment means 1 1 generally comprise screening means, desanding means, de-oiling means, and a UASB methanization reactor (for Upflow Anaerobic Sludge Blanket in English).
• the implementation of these pretreatment means 1 1 leads to the production of primary sludge 12, flared biogas and a pretreated effluent.
• the latter depending on the type of upstream treatment, is routed to biological treatment means 13 comprising for example an aerobic activated sludge reactor, a biofilter, biodisks, lagoons ...
• the effluent from the biological treatment means 13 is introduced into a decanter 14.
• the implementation of the decanter 14 allows to produce a treated effluent 15 which can be routed to a subsequent treatment or rej éé in the natural environment. It also leads to the production of biological sludge.
• a first portion 16 of the biological sludge is recirculated upstream of the biological treatment means 1 3 to regulate sludge concentration and possibly in the UASB reactor.
• a second portion 17 biological sludge is directed with the primary sludge 12 to treatment means 18 whose implementation leads to thicken or dehydrate sludge.
• Sludge treated 19 are then generally oriented towards agronomic valorization sectors.
• UASB technique allows cutting down, at low energy cost, about 50 to 80% of the COD contained in the effluent to be treated.
• the invention particularly aims to overcome these disadvantages of the prior art.
• Another object of the invention is to implement such a technique that allows, in at least one embodiment, to increase the production of biogas compared to the techniques of the prior art.
• the invention also aims to provide, in at least one embodiment, such a technique that can be implemented in many regions of the world, including that in which the temperature of the effluent to be treated is continuously or seasonally below 15 ° C.
• the invention also aims to provide, in at least one embodiment, such a technique that can be implemented in a relatively small footprint and is simple, reliable and inexpensive.
• a liquid effluent treatment process whose temperature is between 5 and 15 ° C, which according to the invention comprises: a step of methanization of said effluent within a methanizer producing biogas, methanized sludge and a methanized effluent; a step of biological treatment of said methanized effluent within a biological treatment zone producing biological sludge and a treated effluent;
• the invention is based on a completely original technique for treating a liquid effluent comprising anaerobic digestion of the effluent within a methanizer, a biological treatment of the methanized effluent from the methanizer, a sludge extraction. thickened biologics from biological treatment, anaerobic digestion of at least a portion of the methanized sludge and thickened organic sludge, and recirculation of at least a portion of the sludge digested to the methanizer.
• the digested sludge 27 is then reintroduced into the methanizer 21.
• this implementation may make it possible to increase the reduction in the COD content of the effluent to be treated, to reduce the volume of sludge produced, to improve the stability and the decantability of the sludge produced, to increase the production of biogas.
• the attention of the reader is however drawn to the fact that the effectiveness of such an implementation to treat effluents at low temperature, that is to say at a temperature below 15 ° C, remains to be demonstrated.
• the inventors have, under these conditions, sought a technical solution that would make it possible to implement, at low temperature, an effluent treatment technique incorporating an anaerobic digestion, the high temperature implementation of which is known to have the advantage of enabling remove the COD content of the effluent to be treated satisfactorily.
• Recirculating at least a portion of the biological sludge in the digester is contrary to the prior art of a person skilled in the art who, in an installation of the type illustrated in FIG. 1, never employs a digester for treat biological sludge whereas anaerobic digestion is already implemented during the anaerobic digestion.
• the implementation of a technique according to the invention makes it possible to reduce the volume of the digester. Indeed, the integration of the technique of N. Mahmoud in an installation of the prior art according to Figure 1 leads to implement an installation according to Figure 4, the volume of the digester is 1.3 times lower than that of the methanizer, while the implementation of the technique according to the invention can lead to implement a digester whose volume is between 3 and 9 times lower than that of the methanizer.
• this technique reduces the overall production of sludge.
• the sludge produced is digested in two different modes.
• some sludge that is insensitive to one of the modes of digestion will be more to the other.
• recirculation of sludge to the methanizer allows the latter to be inoculated with active anaerobic biomass from the digester.
• This biomass, which is active requires no maturation time to act within the methanizer. This recirculation therefore contributes to increasing the yield of the anaerobic digestion.
• the use of the technique according to the invention thus makes it possible to increase the solubilization of the organic fraction of the sludge, which contributes, on the one hand, to reducing sludge production and, on the other hand, to increasing the production of sludge. biogas.
• the particulate organic fraction of the liquid effluents to be treated is difficult to kill by psychrophilic methanization at low temperature.
• the solubilization of this organic fraction is improved by the supply of mesophilic anaerobic sludge from the digester. This makes it possible to overcome the yield limits of low temperature methanation.
• the technique according to the invention thus makes it possible to effectively treat an effluent whose temperature is between 5 and 15 ° C.
• said digestion is of the mesophilic or thermophilic type.
• said methanation is of the psychrophilic or mesophilic type.
• the modes of operation of digestion and methanation can thus be chosen advantageously depending on the nature of the effluent to be treated. If the effluent to be treated is an urban waste water, methanation will be preferentially psychrophilic and mesophilic digestion, whereas if the effluent to be treated is an industrial wastewater, methanation and digestion will be preferentially mesophilic.
• the thermophilic regime will be applied only to sludge digesters and according to local parameters such as effluent temperature and / or implantation constraints. This diet usually reduces the volume of the digester. It is however more energy consuming.
• said biological treatment step comprises an aerobic biological treatment step.
• the aerobic biological treatment may for example implement activated sludge, a biofilter, biodisks, a sequenced biological reactor (SBR) ...
• SBR sequenced biological reactor
• Anaerobic digestion reduces approximately 50 to 70% of the COD of the effluent to be treated. Aerobic biological treatment removes the residual COD contained in the methanized effluent in order to reach acceptable discharge standards for the natural environment. Thus, downstream of the biological treatment, the total reduction of the COD and the MES is greater than 95%, the reduction of the MES being obtained by separating the biological sludge from the treated effluent.
• the biological treatment may also make it possible to eliminate at least part of the nitrogen (for example by thorough nitrification) and / or phosphorus contained in the effluent to be treated and which has not been removed by the methanation.
• said biological treatment step comprises a biological treatment step of anoxic type.
• the implementation of such anoxic biological treatment step can eliminate at least a portion of the nitrogen and / or phosphorus contained in the effluent to be treated that has not been removed by the biological treatment. aerobic.
• Phosphorus can also be removed at least partly by physico-chemical route by addition of ferric chloride or equivalent reagent.
• the biological treatment zone will include means for separating the biological sludge from the treated effluent. These means may for example include a decanter, a membrane block, a float, filter discs, etc.). Biological sludge separated from the treated effluent can typically be thickened before being extracted. As an example, in the case of a settling tank, the thickened organic sludge will be extracted in the lower part of the settling tank, in the case of a membrane block, the biological sludge will be collected by backwashing ... the sludge thickening allows to preconcentrate them before recirculating them.
• a process according to the invention preferably comprises a step of recirculating at least a portion of said thickened biological sludge upstream of the biological treatment zone which will comprise, for example, a biologic reactor under aerobic or anoxic conditions (for example a denitrification reactor). It can therefore be airy or not.
• a method according to the invention advantageously comprises a step of controlling the recirculation flow rate of digested sludge in said methanizer, a step of controlling the recirculation rate of the methanized sludge in said digester, and a step of controlling the extraction rate of said sludge. digested.
• the recirculation and extraction fines will preferably be controlled to maintain the sludge concentration in said methanizer and digester respectively between 10 and 100 gMVS / L and 30 and 100. gMVS / L according to the temperature of said effluent to be treated.
• the abbreviation MVS stands for Volatile Suspended Matter.
• Such an implementation can treat an effluent whose temperature is between 5 and 15 ° C in a small footprint by maximizing the production of biogas and decreasing the production of sludge.
• the present invention also relates to an effluent treatment installation, said installation comprising:
• a methanizer comprising an inlet for said effluent, a biogas outlet, a methanized sludge outlet and a methanized effluent outlet;
• biological treatment means comprising an inlet for said methanized effluent, and a biological sludge outlet;
• digestion means comprising a first inlet cooperating with methanized sludge recirculation means, a second inlet of thickened biological sludge, a biogas outlet and a digested sludge outlet;
• Such an effluent treatment plant preferably comprises means for regulating said recirculation means and extraction means.
• said methanizer may be of the UASB or HUSB or AnMBR type, that is to say an anaerobic membrane bioreactor or Anaerobic Membrane Bio Reactor in English).
• FIGS 1 and 2 illustrate diagrams of two types of liquid effluent treatment plant according to the prior art
• FIG. 3 illustrates the diagram of an effluent treatment plant liquid according to the invention
• FIG. 4 illustrates the schematic of an effluent treatment plant comprising a UA SB methaneurizer and a communicating C SR stelige;
• FIG. 5 illustrates the diagram of a variant of an installation according to the invention implementing an AnMBR type methanizer in place of a UASB methanizer.
• the general principle of the invention is based on a completely original technique for treating a liquid effluent comprising a methanization of effluent within a methanizer, a biological treatment of methanized effluent from the methanizer, an extraction of thickened biological sludge. from the biological treatment, anaerobic digestion of at least a portion of the methanized sludge and thickened organic sludge, and recirculation of at least a portion of the sludge digested to the methanizer.
• FIG. 3 an embodiment of a treatment plant for a liquid effluent according to the invention is presented.
• such an installation comprises a pipe for supplying an effluent to be treated 30.
• This pipe 30 opens at the inlet of pre-treatment means.
• the pretreatment means comprise screening means, grit removal and deoiling 31, and a methanizer 32.
• the methanizer 32 is of the type of expanded anaerobic sludge (or UASB for Upflow Anaerobic Sludge Blanket in English language) intended to operate in psychrophilic mode. In a variant, it can operate in mesophilic mode. In another variant, it may be a type of methanizer expanded hydrolyzed sludge bed (or HUSB for Hydrolysis Upflow Sludge Blanket in English).
• the methanizer 32 houses a triphasic separator. It comprises a biogas outlet 321 which is connected to processing, storage and recovery means (not shown) whose implementation can allow the production of heat and electricity.
• the methanizer 32 also comprises a methanized effluent outlet 33 and a methanized sludge outlet 322.
• the outlet of methane effluent 33 is connected to the inlet of a biological reactor 34 with activated biological sludge.
• other biological treatment techniques may be implemented, for example fixed culture technologies such as Biostyr®, MBBR AnoxKaldnes® or other fixed or hybrid cultures, membrane or disk bioreactor, biological reactor sequential...
• This biological reactor 34 houses aeration means (not shown). It comprises an outlet which is connected by a pipe 35 to the inlet of a settler 36.
• the settler 36 comprises a treated effluent outlet 37 and a thickened biological sludge outlet 38.
• other liquid / solid separation means may be used, such as, for example, aeroflotation means, means filtration ...
• the outlet 38 is connected by a pipe to a T-shaped connection means 39.
• This T-shaped connection means 39 is connected to a pipe 40 which opens into the outlet 33 upstream of the biological reactor 34.
• the T-shaped connection means 39 is also connected to a pipe 41 which opens into a pipe means. thickening or dewatering of sludge organic.
• thickening or dehydration 42 comprise in this embodiment a thickener.
• they may for example include a dewatering device, pressing, centrifugation ...
• the means for thickening or dewatering biological sludges comprise a thickening juice outlet (not shown) which opens upstream of the biological reactor 34. It also comprises a thickened biological sludge outlet which is connected by a pipe 43 to the entry of an anaerobic digester 44.
• the anaerobic digester 44 is of the permanently stirred type (or CSTR for
• Continuously Stirred Tank Reactor in English and is expected to work in mesophilic mode.
• it can operate in thermophilic mode. It comprises a biogas outlet 441 which is connected to the processing, storage and recovery means. It further comprises a digested sludge outlet which is connected to the methanizer 32 via a pipe 45. A digested sludge extraction pipe 47 is connected to the pipe 45.
• the outlet of methanized sludge 322 is connected to the digester 44 via a pipe 46.
• the biogas treatment means may be of the desiccant, desulfurization or siloxane removal type.
• the biogas storage means may be of the compression type to allow the supply of a boiler or a cogenerator.
• the recovery means may include a boiler or a cogenerator.
• the biogas produced within the methanizer 32 and the digester 44 comprises approximately 70% methane and 30% carbon dioxide. It can be used to produce the heat necessary to heat the digester 44 and the electricity used for example to implement the effluent treatment plant. In case of presence of troublesome products (sulphide of hydrogens, siloxanes ...), it will be able to be the subject of a specific treatment before being valorized. In case of large production, it may be exported outside installation.
• This installation also comprises a regulation system.
• This regulation system comprises measuring means:
• the control system comprises valves and / or variable flow rate pumps 48, 49 and 50 which respectively make it possible to modify the flow rate of methanized sludge introduced into the digester 44, to modify the flow rate of digested sludge introduced into the methanizer 32 and to modify the flow of digested sludge extracted from the installation.
• the control system also comprises control means to which the measuring means and the valves 48, 49, 50 are connected.
• the mass load applied to the methanizer 32 must be between
• the pH of the effluent to be treated must be between 6.5 and 7.5.
• control means control the opening of the valves 48, 49, 50 to adjust the flow rates for recirculation and extraction of sludge in such a way that the concentration of sludge in the digester 44 is included between 30 and 100g MVS / L and that the concentration of sludge in the methanizer 32 is between 10 and 100g MVS / L.
• the extraction of the sludge from one or both reactors 32, 44 makes it possible to adapt the mass loads in each reactor so that they remain in the abovementioned intervals when the recirculation of sludge between the reactors does not occur. does not compensate for sudden changes in temperature and incoming charge.
• the objective of the regulations is to maintain the methanizer and the digester under optimal conditions of methanogenic activity in order to reduce the production of sludge and increase the production of biogas.
• the digester is always regulated at the optimum temperature, but not the methanizer. Therefore, it must be inoculated continuously with biomass from the digester in order to benefit from optimal methanogenic activity.
• the treatment of an effluent by means of an installation as described above is to convey via the pipe 30 this effluent to the pretreatment means 31 in such a way that it is rid of sands and oils that 'it contains.
• the desalted and deoiled effluent is then introduced into the UASB type reactor 32 in which it undergoes anaerobic digestion.
• the methanizer 32 will operate in psychrophilic mode, at ambient temperature of the waste water without heating, with a hydraulic residence time of the effluents of between 2 and 15 hours, advantageously between 2 and 12 hours, to ensure their methanisation.
• the methanizer 32 will operate in mesophilic mode, at a temperature of around 37 ° C., with a sludge hydraulic residence time of a few hours depending on the volume load applied, which is generally between 5 and 30 ° C. Kg COD / m 3 / d.
• This methanisation leads to the production of biogas that is stored, treated and upgraded, and a pre-treated effluent.
• the methanized effluent is introduced into the biological treatment means 34 in which it undergoes a biological treatment.
• This biological treatment leads to the production of biological sludge.
• the biological sludge is conveyed to the decanter 36, the implementation of which allows the production of a treated effluent 37 and thickened organic sludge 38.
• the thickened organic sludge is partly recirculated at the inlet of the biological treatment means 34. This recirculation makes it possible to regulate conventionally the concentration of sludge in the biological treatment means 34.
• the remainder of the thickened biological sludge is introduced into the means sludge treatment 42.
• the biological sludge is dehydrated and / or thickened before being introduced into the reactor 44 of the CSTR type.
• the thickened organic sludge is mixed in this reactor 44 with the sludge from the methanizer 32. This mixture of sludge undergoes anaerobic digestion inside the digester 44.
• the digester 44 will generally operate in mesophilic mode at a temperature between 35 and 37 ° C, with a sludge hydraulic residence time of between 15 and 20 days.
• This digestion leads to the production of biogas that is stored, processed and upgraded, and digested sludge.
• NGL global nitrogen
• total phosphorus 10 mg / L;
• a first series of tests consisted in treating such an effluent in an installation such as that illustrated in FIG. 4.
• This installation differs from that illustrated in FIG. 1 because the methanized sludge 12 leaving the methanizer 11 are recirculated in a CSTR 40 type digester whose implementation leads to the formation of biogas 42 and digested sludge which are partly recirculated 43 in the methanizer 11 and partly extracted 41.
• a portion of the biological sludge thickened and some of the digested sludge is extracted directly from the facility.
• the pretreatment was of UASB methanization type with a hydraulic residence time of 8.5 hours at 20 ° C, the biological treatment by activated sludge with high load, mesophilic CSTR digestion in recirculation with the UASB reactor.
• a second series of tests consisted in treating such an effluent in an installation according to the invention such as that illustrated in FIG. 3.
• the pretreatment was of the UASB methanization type with a residence time of 8.5 hours at 20 ° C, the biological treatment by activated sludge at high load, mesophilic CSTR digestion treating both the fresh sludge from the decantation and the biological sludge, with implementation of reciruclation between the UASB reactor and the CSTR digester.
• the volume of the CSTR reactor is 1.3 times lower than that of the UASB reactor.
• the decrease in the overall sludge production is partly due to the fact that sludge retention times in the anaerobic phase are cumulative: ie 30 to 60 days in the UASB and 10 to 20 days in the CSTR, so a total sludge residence time under anaerobic conditions of 40 to 80 days over the entire wastewater treatment plant.
• NGL global nitrogen
• PT total phosphorus: 10 mg / L; Temperature 20 ° C.
• NGL global nitrogen
• total phosphorus 10 mg / L;
• Hydraulic residence time 20 days;
• the implementation of the recirculation regulation according to the invention In this case, it is possible to reduce the recirculation flow rate between the CSTR and the UASB and to increase the sludge extraction rate of the CSTR from 200 to 400 m 3 / h. This makes it possible to return to an acceptable MVS concentration in the CSTR while maintaining the control instructions for the reactors.
• the ratio between the volume of the CSTR and the volume of the UASB is between 3 and 9, and preferably between 4.5 and 5.5, which renders the technique according to the invention economically viable;
• a technique according to the invention can alternatively implement a UASB or HUSB type methanizer.
• the average residence time of the effluents to be treated is about 2.5 hours in a HUSB type reactor, and about 8 hours in a UASB type reactor.
• the average yield in terms of total COD abatement is about 43% within a HUSB, and about 50% and can reach 70% optimum operation within a UASB.
• the average return in terms of SSM reduction is about 83% in a HUSB, and more than 80% in a UASB.
• the means for aerobic treatment of methanized effluents leaving a UASB are less bulky than those used to treat methanized effluents from a HUSB.
• Particulate COD is partially solubilized and converted to volatile fatty acids (VFA) in a HUSB. It is partially solubilized and transformed into biogas within a UASB. In other words, the denitrification of methanized effluents from a HUSB is better than that of methanized effluents from a UAS
• a HUSB methanizer produces little biogas. It nevertheless transforms a portion of the COD into AGV, the presence of which in the methanized effluents from the HUSB tends to improve their subsequent denitrification. In addition, considering the recirculation between the two anaerobic reactors, some of the AGV is still transformed into biogas. In the end, the implementation of a HUSB methanizer in substitution of a UASB reactor in a technique according to the invention leads to produce a globally satisfactory amount of biogas. In addition, the volume of a HUSB methanizer is about three times lower than that of a UASB methanizer, which may be of economic interest.
• the methanizer 32 UASB or HUSB is replaced by a methanizer type AnMBR (Anaerobic Membrane Bio Reactor).
• This methanizer 32 thus consists of an anaerobic membrane bioreactor.
• Such anaerobic membrane bioreactor may for example be that marketed by the Applicant under the name MEMTHA E ®.
• such a methanizer 32 comprises an anaerobic bioreactor 320 as well as a membrane separation unit 323.
• the bioreactor 320 comprises an effluent inlet to be treated in which a pipe for supplying an effluent to be treated, possibly pre-treated beforehand, 51 opens. It also comprises a biogas outlet 321, an outlet for methanized sludge 322 and an outlet for effluent 324.
• the effluent outlet 324 opens at the inlet of the membrane separation unit 323.
• This membrane separation unit 323 houses micro or ultrafiltration filtration membranes of mineral type, for example ceramic, or organic. It comprises a methanized effluent outlet 33 which opens into the biological treatment zone 34. In this case, methanized effluent is a permeate. It also comprises a retentate outlet connected to a recirculation pipe 325, which opens into the bioreactor 320.
• the outlet of methanized sludge 322 from the bioreactor 320 is connected to a pipe 46 which opens into the digester 44.
• the bioreactor 320 further comprises a digested sludge inlet into which a pipe 45 opens, the inlet of which is connected to the outlet of the digester 44.
• the desalted and deoiled effluent from the pretreatment means 31 is introduced into the bioreactor 320 of the methanizer 32. It undergoes anaerobic digestion.
• the bioreactor 320 will operate in psychrophilic mode, at ambient temperature of the wastewater without heating, with a hydraulic residence time of the effluents of between 2 and 15 hours and advantageously between 2 and 12 hours to ensure their methanation.
• the bioreactor 320 will operate in mesophilic mode, at a temperature of around 37 ° C, with a sludge hydraulic residence time of a few hours depending on the applied volume load which is generally between 5 and 30 ° C. Kg COD / m 3 / d.
• the methanized effluent generated during this methanation is introduced into the membrane separation unit 323, the implementation of which leads to the production of a methanized permeate and a concentrate.
• the concentrate is recirculated in the bioreactor 320 via line 325.
• the effluent or methanized permeate is introduced via line 324 into the biological treatment means 34 in which it undergoes a biological treatment.
• Methanized sludges from the bioreactor 320 are introduced into the digester 44 via the pipe 46.
• the sludge mixture present in the digester 44 undergoes anaerobic digestion.
• the digester 44 will generally operate in mesophilic mode at a temperature between 35 and 37 ° C, with a sludge hydraulic residence time of between 15 and 20 days. Digested sludge from digester 44 is introduced into bioreactor 320 via line 45.
• the conventional treatment of an effluent by methanization type AnMBR does not produce a good result when the temperature thereof is less than 15 ° C.
• the implementation of the technique according to the invention allows an efficient treatment by anaerobic digestion of the AnMBR type of an effluent at low temperature, that is to say whose temperature is less than or equal to 15 ° C. and in particular between 5 ° C and 15 ° C.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Microbiology (AREA)
• Biodiversity & Conservation Biology (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Molecular Biology (AREA)
• Treatment Of Sludge (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=44462043

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (3)

Citations (4)

Family Cites Families (1)

• 2011
  • 2011-02-01 FR FR1150766A patent/FR2970961B1/fr not_active Expired - Fee Related
• 2012
  • 2012-02-01 BR BR112013018301A patent/BR112013018301A2/pt not_active IP Right Cessation
  • 2012-02-01 MX MX2013008738A patent/MX2013008738A/es unknown
  • 2012-02-01 CN CN201280007283.1A patent/CN103796959B/zh not_active Expired - Fee Related
  • 2012-02-01 AR ARP120100322 patent/AR085102A1/es unknown
  • 2012-02-01 WO PCT/EP2012/051636 patent/WO2012104330A1/fr active Application Filing

Patent Citations (4)

Non-Patent Citations (3)

Also Published As

Similar Documents

Legal Events