Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
  • B01D65/08—Prevention of membrane fouling or of concentration polarisation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/14—Ultrafiltration; Microfiltration
  • B01D61/18—Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
  • B01D65/02—Membrane cleaning or sterilisation ; Membrane regeneration
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
  • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
• • 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
  • C02F3/1205—Particular type of activated sludge processes
  • C02F3/1226—Particular type of activated sludge processes comprising an absorbent material suspended in the mixed liquor
• • 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
  • C02F3/1268—Membrane bioreactor systems
  • C02F3/1273—Submerged membrane bioreactors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2321/00—Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
  • B01D2321/18—Use of gases
  • B01D2321/185—Aeration
• • 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 invention relates to the field of filtration and purification installations for water treatment.
• the invention applies more precisely to the purification of water such as, in particular, underground, deep or karst water or surface water.
• water treatment installations with a view to their drinking water generally comprise a succession of physical-chemical treatment units of the flocculation / decantation / filtration type, supplemented by an oxidation unit.
• Flocculation is a physicochemical step which aims to modify the state of the colloidal particles contained in water by adding a coagulant (polychloride of aluminum, sulphate of alumina, ferric chloride ...) in order to be able remove them by decantation.
• a coagulant polychloride of aluminum, sulphate of alumina, ferric chloride
• Micro-organisms, micro-pollutants, compounds (ferrous iron, manganese %) which cannot be eliminated by flocculation, are generally oxidized thanks to the use of powerful oxidants such as ozone, chlorine, or even chlorine dioxide.
• micropollutants can also be carried out by adsorption on activated carbon or even by stripping (forced aeration) if they are volatile.
• the filtration step aimed at removing the particles in suspension is conventionally carried out on one or more beds of non-reactive pulverulent materials, such as sand filters.
• a conventional water treatment installation with a view to making it drinkable could thus consist of a flocculation unit, followed by a decantation unit, a filtration unit (for example on sand), a unit ozonation, a filtration unit on activated carbon in grain or powder, and finally disinfection.
• a membrane filtration method has recently been proposed, implementing a circulation loop for the water to be treated, including at least one tangential filtration membrane, with ozone injection in the loop. traffic.
• Applicant to grow an activated sludge in drinking water.
• the implementation of such an activated sludge with means for clarification vector result in a loss of biomass per exhaust in the clarified water exceeds production preventing achieve a sufficient sludge age.
• the objective of the present invention is to present an installation for the drinking water does not show the drawbacks of prior art installations.
• Another objective of the present invention is to propose an installation for treating water with a view to making it drinkable, implementing a step of biological treatment.
• Another objective of the invention is to propose such an installation that can be produced at lower cost by rehabilitating existing installations for the purification of water using conventional filters such as sand filters.
• Another objective of the invention is to describe such an installation combining the interests of biological treatment with those of treatments using compounds allowing the adsorption of micro-pollutants or nitrogen pollution, such as powdered activated carbon, clays, zeolites ...
• Another objective of the invention is also to include in a water treatment installation one or more filtration membranes, while allowing the maintenance of high treatment currents.
• Another objective of the present invention is also to propose an installation for the treatment of drinking water with great flexibility of use and which can be used at temperatures at which the biological activity is low or zero.
• the invention thus presents the originality of proposing to make water drinkable using an activated sludge, while the state of the art largely dissuaded those skilled in the art from using free biomass in the context of a such process.
• the use of an activated sludge is made possible thanks to the use of at least one microfiltration or ultrafiltration membrane which makes it possible to retain the biomass within the reactor and therefore to prevent it from migrating outside that -this.
• the use of such a membrane thus makes it possible to obtain a sufficiently large mud age to allow the purification of the water.
• the invention also has the originality of proposing the addition of at least one pulverulent material in the reactor during the drinking water treatment.
• a material makes it possible to promote the development of the biomass by serving as a support for the latter.
• the pulverulent material used may constitute a reactive powder contributing directly to the purification of water by adsorbing on its surface the substrates (organic materials, NH 4 ) necessary for the biomass.
• These reactive powders can thus be chosen as a function of the composition of the waters to be made potable and in particular as a function of their organic matter and NH4 content.
• Activated charcoal powder can thus be used to allow a high adsorption of organic materials and a light adsorption of NH 4 , while zeolites will rather be used to allow a strong adsorption of NH 4 and a light adsorption of organic materials .
• the installation according to the invention therefore makes it possible to advantageously combine, within a single reactor, the interests aroused by a biological treatment and by filtration through membranes.
• the fixed biomass makes it possible to degrade biodegradable carbon pollution (CODB) as well as nitrogen pollution, and the membranes make it possible both to carry out a filtration of the water and to remove the suspended solids while effectively preventing migration biomass.
• CODB biodegradable carbon pollution
• the membranes make it possible both to carry out a filtration of the water and to remove the suspended solids while effectively preventing migration biomass.
• reactive powders which can be introduced on demand into the waters to be made potable depending in particular on the composition of these waters.
• a powder material in the reactor can therefore be used for introducing into the water present therein any non-reactive powder material serving as a support for the biomass implementation, such as for example sand or anthracite and to introduce into these waters or a several reactive powders of various natures.
• reactive powders are understood, within the framework of the present description, to refer to any powder capable of reacting with one of the compounds present in the waters to be made potable, either by adsorption or by exchange of ions, with a view to reducing the content of these compounds in the waters in question.
• These powders must also also have physical characteristics of hardness, abrasiveness and density allowing their fluidization in the water present in the reactor and making them compatible with the membranes used.
• These reactive powders can advantageously, thanks to the installation according to the invention, be introduced into the water to be treated as a function of the composition thereof and in particular as a function of their load of micro-pollutants and particularly of pesticides (atrazine, simazine etc.) which are compounds which are very difficult to eliminate biologically.
• These reactive powders can also be used to rid the waters of the toxic metals they contain, such as cadmium or lead.
• these reactive powders may also be used to adsorb carbon or nitrogen pollution when the biomass used in the reactor is little or not active, taking into account the Too low temperature of the water to be drunk passing through the reactor.
• the use of these reactive powders will make it possible, if necessary, to functionally take over from the biomass, which will give the installation according to the invention a very great flexibility of use, by authorizing its use whatever or the temperature of the water to be treated.
• the means for injecting oxygenated gas from the installation have mainly four objectives. First, they authorize the supply of oxygen necessary for the respiration of the biomass present in the reactor. Secondly they ensure the fluidization of the powders also present therein. Thirdly, they make it possible to ensure the intimate mixing of said powders with water and finally they make it possible to stir the membranes immersed in the reactor so as to prevent, or at least delay, their clogging.
• Such a characteristic is particularly interesting since it allows the rehabilitation of obsolete drinking water stations into new stations leading to better results without resorting to the construction of a new civil engineering. It is thus possible to considerably reduce the costs generally induced by the installation of new equipment.
• said reactive powder is chosen from the group consisting of powdered activated carbon, zeolites, clays and exchange resins.
• Powdered activated carbon (PAC) can preferably be used as a compound adsorbing micro-pollutants and in particular pesticides.
• the CAP can therefore in particular be added to the periods of the year during which the waters are heavily loaded with these compounds and in particular in spring.
• Zeolites, clays and exchange resins can be used to capture nitrogen pollution in the event of a deficiency in biomass activity due to a drop in temperature or even be used to capture metals.
• said installation also comprises at least one anoxic pre-denitrification unit upstream of said biological reactor.
• anoxic pre-denitrification unit upstream of said biological reactor.
• the use of a denitrification tank in combination with a nitrification tank is well known in the field of waste water treatment. However, hitherto such use has not been possible in the context of drinking water treatments, taking into account the risks of entrainment of bacteria towards the subsequent stages of treatment.
• Such pre-denitrification is made possible thanks to the installation according to the invention insofar as such a risk is eliminated by the presence of hollow fiber filtration membranes whose pore size is provided to prevent the passage of any micro -organisms in the filtrates.
• the installation comprises pre-treatment means provided upstream of said biological reactor, including means for clarification.
• pretreatment means can also include a flocculation / coagulation unit upstream of said clarification means.
• Such pretreatment means can also be produced from the pretreatment means of a conventional installation on a rehabilitated sand filter.
• said biological reactor has in its lower and upper part means for purging sludge. The sludge recovered by these purging means can be redirected to the sludge treatment means.
• the civil engineering used to carry out said installation results from the conversion of an existing civil engineering of a water purification plant by physical filtration on granular material, said biological reactor being constituted by a filtration basin on granular material of said drinking water installation.
• upstream denitrification means does not prevent such rehabilitation of an existing installation, the size of the sand filters allowing the compartmentalization of these to form both a predenitrification basin and a biological nitrification and filtration reactor on hollow fiber membranes.
• the installation comprises means for measuring the concentrations of pollutants in the water to be treated to which said means for adding at least one pulverulent material are controlled.
• the invention also relates to a process for the biological treatment of water with a view to its drinking water, characterized in that it consists in passing the water through an installation as described above and in using said means for adding said installation to allow the addition to said reactor of at least one pulverulent material serving as a support for the biomass and / or the at least intermittent addition to said reactor of at least one reactive powder, said reactive powder being added as a function pollutants present in the raw water and / or the temperature of the water to be made potable.
• the method according to the invention therefore also has the original characteristic of reinforcing the role of biological support filled by the pulverulent material when the conditions of the drinking water treatment require it by the addition of at least one reactive powder.
• the method according to the invention is thus implemented when the temperature of the water to be made potable authorizes normal biological activity of said biomass allowing the biological degradation of CODB and of the nitrogen pollution it contains, and consists in using said means for adding a pulverulent material to distribute at least one reactive powder in said reactor according to at least one parameter chosen from the group consisting of the pesticide content of the water , the DOC content of water and the heavy metal content of water.
• the temperature at which the metabolism of bacteria is inhibited is of the order of 4-5 ° C.
• the installation according to the invention can therefore be used to add at least periodically, using the means provided for this purpose, one or more reactive powders responsible for reducing pollution non-biodegradable carbon, pesticides as well as the metals contained in the drinking water.
• the fixed bacteria are responsible for the elimination of biodegradable carbon pollution and the elimination of nitrogen pollution.
• the pulverulent material used will preferably be powdered activated carbon to remove pesticides and zeolites to adsorb the heavy metals present.
• the reactive powders whose adsorbing power is exhausted can be stored in said biological reactor, these then constituting a non-reactive pulverulent material serving as a support for fixing to the biomass.
• said means for adding pulverulent material are used when the temperature of the water to be drunk inhibits the activity of said biomass, in order to distribute at least one first reactive powder charged with the adsorption of organic compounds and at least a second reactive powder charged with the adsorption of ammonia pollution.
• the reactive powders are added to capture the undesirable compounds present in the water treated and substitute thus to the action of bacteria.
• said first powder is preferably activated carbon in powder form and said second powder is preferably chosen from the group consisting of zeolites and clays.
• the method then comprises a step consisting in renewing the first and second powders when the adsorption capacity of the latter comes to an end.
• FIG. 1 schematically represents an installation according to the present invention
• - Figure 2 represents the evolution over time of the atrazine concentrations of the water to be treated and the water treated thanks to the installation shown in Figure 1
• - Figure 3 represents the evolution over time of ammonia concentrations of the water to be treated and the water treated using the installation shown in Figure 1.
• the raw water (EB) to be treated arrives in the installation represented by a pipe 1.
• the water is then conveyed to pretreatment means constituted by a coagulation / flocculation unit 3 and a clarifier 4.
• pretreatment means constituted by a coagulation / flocculation unit 3 and a clarifier 4.
• these preprocessing means are optional.
• the coagulation / flocculation unit 3 comprises means 5 for dispensing a coagulating reagent (polychloride of aluminum, alumina sulphate, ferric chloride ...) making it possible to coagulate the colloidal materials which are in suspension in the water.
• a coagulating reagent polychloride of aluminum, alumina sulphate, ferric chloride Certainly it possible to coagulate the colloidal materials which are in suspension in the water.
• the mixture of water and coagulated materials is then directed to the clarifier 4 in order to there decant.
• the sludge from this decantation under racked in 6.
• the overspray of the clarifier 4 is then sent to a biological reactor
• An ultrafiltration module 1 1 made of hollow fibers at external pressure
• the treated water (ET) is recovered at the outlet of the pipe 12 and passes through a tank 13 before being evacuated from the installation.
• means for adding pulverulent materials are provided.
• non-reactive powders such as sand or anthracite serving as a support for fixing to a biomass, as reactive powders, continuously or intermittently.
• These reactive powders preferably consist of powdered activated carbon
• CAP CAP
• zeolites zeolites, clays or ion exchange resins
• means 10a for measuring the concentrations of pollutants in the water to be treated are provided, said means 10 for adding powdery materials being controlled by these means 10a.
• the reactor 7 is equipped with means for injecting an oxygenated gas, in this case air, constituted by two injection ramps 9, 9a provided in the lower part of the reactor.
• an oxygenated gas in this case air
• two injection ramps 9, 9a provided in the lower part of the reactor.
• the aeration means 9 make it possible both to maintain in suspension the powders present in the reactor 7, to mix water with these powders, to provide the necessary oxvsurgeon bacteria and shake ies immersed membranes to the unclog.
• the reactor 7 also has means for purging the sludge 14 in its lower part to evacuate the low purges by a pipe 15, the high purges of the reactor 7 being in turn evacuated by a pipe 16.
• the high purges consist essentially of fines of powdery materials and low purges of decantable materials. These purges make it possible to standardize the particle size of the powders present in reactor 7.
• the bottom purge makes it possible to manage the age of the sludge in the reactor by the following formula:
• Age of sludge volume of reactor / volume of daily purge. Furthermore, the hydraulic residence time (TRH) of the water to be treated in the reactor is given by the following formula:
• TRH reactor volume / treated water flow.
• Powdered activated carbon, or another reactive adsorbent powder is injected into the reactor, using the slip 10 when the water to be treated requires elimination of the dissolved organic pollution (from March to August for example ).
• Table 1 gives the physicochemical and bacteriological quality of the water to be treated (EB) and the water treated (ET) by the installation described above.
• Table 1 physico-chemical and bacteriological quality of the water to be treated and treated by the system.
• the reactor "in biological operation” ensured elimination of the biodegradable organic carbon, to reach concentrations in the treated water of 0.2 to 0.3 mg / 1.
• Table 3 gives the yield of elimination of ammonia by a zeolite: the clinoptilolite.
• a treatment rate of 30 ppm and a hydraulic residence time of 20 minutes allows a reduction of 56% for concentrations in the water to be treated of 0.5 mg / 1.
• This adsorption function makes it possible to extend the residence time of the ammonia in the reactor when the biological nitrification kinetics are slow.
• the installation described here has the advantage of being able to be produced from an existing drinking water installation on a sand filter.
• the reactor 7 can thus be formed in the basin originally hosting the sand bed used by the filtration.
• the invention therefore provides an interesting solution for rehabilitating such conventional installations and makes it possible to obtain improved water purification at a lower cost.

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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Water Supply & Treatment (AREA)
• Organic Chemistry (AREA)
• Environmental & Geological Engineering (AREA)
• Hydrology & Water Resources (AREA)
• Microbiology (AREA)
• Biodiversity & Conservation Biology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Water Treatment By Sorption (AREA)
• Biological Treatment Of Waste Water (AREA)
• Activated Sludge Processes (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)

Priority Applications (7)

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Related Child Applications (1)

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Citations (8)

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• 1995
  • 1995-07-25 FR FR9509336A patent/FR2737202B1/fr not_active Expired - Fee Related
• 1996
  • 1996-07-25 AU AU67035/96A patent/AU6703596A/en not_active Abandoned
  • 1996-07-25 DE DE69613458T patent/DE69613458T2/de not_active Expired - Lifetime
  • 1996-07-25 CA CA 2199517 patent/CA2199517C/en not_active Expired - Fee Related
  • 1996-07-25 EP EP19960927087 patent/EP0809611B1/fr not_active Expired - Lifetime
  • 1996-07-25 WO PCT/FR1996/001180 patent/WO1997005072A1/fr not_active Ceased
  • 1996-07-25 JP JP50728697A patent/JPH10512192A/ja not_active Withdrawn
  • 1996-07-25 DK DK96927087T patent/DK0809611T3/da active
• 2007
  • 2007-08-07 JP JP2007205611A patent/JP2007313508A/ja active Pending

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