Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J49/00—Regeneration or reactivation of ion-exchangers; Apparatus therefor
  • B01J49/50—Regeneration or reactivation of ion-exchangers; Apparatus therefor characterised by the regeneration reagents
  • B01J49/57—Regeneration or reactivation of ion-exchangers; Apparatus therefor characterised by the regeneration reagents for anionic exchangers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/345—Regenerating or reactivating using a particular desorbing compound or mixture
  • B01J20/3475—Regenerating or reactivating using a particular desorbing compound or mixture in the liquid phase
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/3416—Regenerating or reactivating of sorbents or filter aids comprising free carbon, e.g. activated carbon
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/3441—Regeneration or reactivation by electric current, ultrasound or irradiation, e.g. electromagnetic radiation such as X-rays, UV, light, microwaves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J49/00—Regeneration or reactivation of ion-exchangers; Apparatus therefor
  • B01J49/80—Automatic regeneration
  • B01J49/85—Controlling or regulating devices therefor
• • 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
  • C02F1/28—Treatment of water, waste water, or sewage by sorption
  • C02F1/283—Treatment of water, waste water, or sewage by sorption using coal, charred products, or inorganic mixtures containing them
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/305—Endocrine disruptive agents
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/306—Pesticides
• • 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
  • C02F2303/16—Regeneration of sorbents, filters

Definitions

• the invention relates to the field of fluid treatment systems, in particular water, implementing an adsorption step on an adsorbent medium. More particularly, the invention relates to a method for regenerating an adsorbent medium, on the site of use of the adsorbent medium, as well as a method for treating a fluid implementing said regeneration method. Finally, the invention also relates to an installation for implementing the regeneration process and an installation for implementing the process for treating a fluid.
• these emerging pollutants are poorly adsorbable, whether they are pollutants in the form of small molecules, polar molecules, or hydrophilic molecules.
• the level of these emerging pollutants at the end of the treatment process can then exceed the regulatory thresholds if these pollutants are specifically regulated or in any event present a risk to be anticipated for emerging pollutants not yet regulated.
• adsorbents such as activated carbon
• see their adsorption capacity decrease as they are used to adsorb pollutants.
• Manufacturers implement operations to renew and/or regenerate the adsorbent media in order to increase the adsorption capacity of the adsorbent media.
• State-of-the-art regeneration methods are generally implemented using complex and expensive techniques, requiring different solvents and/or a lot of energy, and transporting adsorbent media outside the treatment site of a fluid. .
• the invention relates to a method for regenerating at least part of the adsorbent medium of at least one adsorption reactor implemented in a fluid treatment unit, said regeneration method being implemented on the site use of the adsorption reactor and comprising: at least one step of removing at least a portion of the adsorbent medium from said at least one adsorption reactor, and at least one step of chemical regeneration comprising a step of bringing into contact of said portion of adsorbent media with a regeneration solution comprising water and sodium hydroxide.
• said portion of adsorbent medium is taken from said at least one adsorption reactor and is introduced into a regeneration reactor before the regeneration step.
• the regeneration solution is at a temperature less than or equal to 60° C., preferably ranging from 20 to 50° C., more preferably from 30 to 40° C. during the step of chemical regeneration.
• the adsorbent medium is rinsed using a rinsing solution, said rinsing solution preferably comprising water, even consisting of water.
• the chemical regeneration step further comprises a draining step at the end of the step of contact with the regeneration solution, said draining step being implemented before the rinsing step.
• the regeneration method further comprises a step of electrochemical regeneration of the adsorbent medium carried out before or after or during the chemical regeneration step.
• said portion of adsorbent media represents a quantity by volume less than or equal to 50% of the volume of absorbent medium, preferably a quantity by volume less than or equal to 30% of the volume of absorbent medium, preferably again a quantity by volume ranging from 1 to 10% of the volume of adsorbent medium.
• the fluid to be treated is chosen from water, an urban effluent, an industrial effluent, preferably, the fluid to be treated is water, and/or
• the adsorbent medium is chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the adsorbent medium is a granular activated carbon.
• the regeneration process further comprises a step of introducing at least one portion of regenerated adsorbent medium into at least one adsorption reactor, identical to or different from the adsorption reactor containing the portion of adsorbent media that has been regenerated.
• the regeneration method is implemented periodically, and comprises a step of determining the next regeneration step on the basis of the age of the adsorbent medium, characterized for example by the rate reduction in at least one target pollutant, and/or by the volume of bed treated and/or by the iodine index of the adsorbent medium.
• the portion of adsorbent media sampled has an actual reduction rate of at least one target pollutant ranging from 40 to 80% and/or a bed volume treated by said adsorbent media ranges from 20 000 to 100,000 BVT (“bed volume treated” in English, more commonly referred to as “bed volume”, abbreviated respectively to BVT and BV)., preferably from 30,000 to 75,000 BVT, more preferably from 40,000 to 60 000 BVT and/or an iodine number ranging from 500 to 800 mg/g.
• the invention also relates to a method for treating a fluid in a treatment unit comprising at least one shutdown phase and at least one production phase, in which said at least one production phase comprises the passage of a fluid to be treated through a bed of adsorbent media within at least one adsorption reactor and in which said at least one shutdown phase comprises the implementation of a regeneration process according to the invention.
• the adsorption reactor can continue to produce; regeneration does not require stopping the treatment reactor.
• part of the adsorbent medium preferably granular activated carbon, is extracted from said processing unit during a production phase or when the unit is stopped, preferably during a production phase.
• the process for treating a fluid further comprises a step for measuring the age of the adsorbent medium, preferably implemented by measuring the actual reduction rate in at least one target pollutant by the adsorbent medium, and/or by measurement of the bed volume treated by the adsorbent medium, and/or by measurement of the iodine number of the adsorbent medium.
• the invention finally relates to a unit for processing a fluid for implementing the method according to the invention, said processing unit comprising:
• At least one reactor for adsorption of pollutants contained in the fluid to be treated comprising within it an adsorbent medium
• the processing unit according to the invention further comprises at least one regeneration reactor comprising an adsorbent media inlet pipe from said at least one adsorption reactor and a outlet making it possible to reintroduce the regenerated adsorbent medium into at least one adsorption reactor identical to or different from the adsorption reactor from which the absorbent medium to be regenerated originated.
• at least one regeneration reactor comprising an adsorbent media inlet pipe from said at least one adsorption reactor and a outlet making it possible to reintroduce the regenerated adsorbent medium into at least one adsorption reactor identical to or different from the adsorption reactor from which the absorbent medium to be regenerated originated.
• the invention makes it possible to regenerate an adsorbent medium by a simpler process than those of the state of the art, which consumes less energy.
• the method of the invention makes it possible to regenerate the adsorbent media directly on the fluid treatment site, using less expensive reagents and a simplified installation since it makes it possible to dispense with heavy installations of storage of adsorbent media.
• the adsorbent medium can be removed during a shutdown phase or a production phase of the treatment method and then directly reintroduced during this same shutdown phase or production phase, thus limiting the adsorbent media storage devices.
• the regeneration process according to the invention can be implemented regularly, even on a poorly saturated adsorbent medium (relatively young age).
• the regeneration method according to the invention makes it possible to improve the adsorption capacity of adsorbent media, thus allowing molecules that are difficult to adsorb to be adsorbed satisfactorily throughout the process for treating a fluid.
• the regeneration process of the invention can be implemented easily and regularly in order to have a quality of adsorbent media, in terms of adsorption performance, which is almost constant, thanks to a regeneration implemented when the adsorbent media is far from being completely saturated (so-called young age adsorbent media).
• FIG. 1 represents a diagram of a regeneration process according to the invention.
• FIG. 2 represents the efficiency coefficient of the regeneration process implemented with two different waters in the regeneration solution, evaluated for different pollutants.
• FIG. 3 represents the efficiency coefficient of the regeneration process implemented with two soda concentrations, evaluated for different pollutants.
• FIG. 4 represents the efficiency coefficient of the regeneration process implemented with three different quantities of regeneration solution, evaluated for different pollutants.
• FIG. 5 represents the efficiency coefficient of the regeneration process implemented with three GAC/soda contact times, evaluated for different pollutants.
• FIG. 6 represents the efficiency coefficient of the regeneration process after a rinsing step, evaluated for different pollutants.
• FIG. 7 represents the efficiency coefficient of the regeneration process after a static rinsing step implemented with two different rinsing waters, evaluated for different pollutants.
• FIG. 8 represents the efficiency coefficient of the regeneration process after a dynamic rinsing step implemented with two different rinsing waters, evaluated for organic matter.
• FIG. 9 represents the efficiency coefficient of the regeneration process, when the SAB test is implemented immediately or 24 hours after a regeneration step, evaluated for different pollutants.
• FIG. 10 represents the efficiency coefficient of the regeneration process, when the rinsing step is implemented immediately or 24 hours after a regeneration step, evaluated for different pollutants.
• the invention relates to a method for regenerating an adsorbent medium used in the treatment of a fluid containing pollutants.
• the invention relates to a method for regenerating at least part of the adsorbent medium of at least one adsorption reactor implemented in a fluid treatment unit, said regeneration method being implemented on the site of use of the adsorption reactor and comprising:
• At least one chemical regeneration step comprising a step of bringing said portion of adsorbent media into contact with a regeneration solution comprising water and sodium hydroxide.
• the invention can be implemented on different types of adsorbent media capable of eliminating different types of pollutants.
• the adsorbent medium is chosen from granular activated carbon (GAC), anion exchange resin, biomaterials, molecularly imprinted polymers (MIP) and mineral materials.
• GAC granular activated carbon
• MIP molecularly imprinted polymers
• adsorbents such as modified clays and cyclodextrin polymers have also shown their effectiveness for certain specific micropollutants such as perfluorinated compounds (PFAs).
• PFAs perfluorinated compounds
• the adsorbent medium is activated carbon.
• Activated carbon is a material consisting essentially of carbonaceous matter with a porous structure. It can be produced in a known manner by pyrolysis of precursors of natural origin (wood, bark, coconut shells, coal, peat, cotton, organic matter of various origins, etc.) or of synthetic origin (polyacrylonitrile ( PAN), aramid fibres, etc.) already containing a significant proportion of carbon, this pyrolysis step being followed by a chemical or physical activation step.
• PAN polyacrylonitrile
• Activated carbon is generally effective in removing long chain PFAS by hydrophobic interaction.
• Biomaterials can also be implemented within the scope of the invention, including biochar.
• Biochar is a composition comprising pyrolyzed biomass biochar, biomass biochar produced by hydrothermal carbonization, or a combination thereof.
• the biomass can be chosen from waste from agricultural crops, forest waste, algae, animal or human waste, industrial waste, municipal waste, waste from anaerobic digesters, raw materials plants grown for biomass production, or a combination thereof.
• biochars made from hardwoods and pine trees can be considered.
• Biochar from rice husks can also be considered, in powder/granular form or in fiber form as in US2019270041 A1.
• the biochar can be a powdered solid or granules.
• the biochar can also include a metal salt powder or granule.
• the metal salt can include iron, aluminum, calcium, magnesium, manganese, zinc, copper or a combination thereof, and in some examples the metal salt includes ferrous or ferric cations, ferrate anions, or a combination thereof. In particular embodiments, the metal salt includes ferric chloride.
• the determination method of the invention is implemented to determine the remaining capacity of an adsorbent medium chosen from granular activated carbon (GAC), other aforementioned adsorbent media (clays, polymer, biochar... ).
• GAC granular activated carbon
• the method of the invention can be implemented with different types of CAG.
• the adsorbent medium is chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the adsorbent medium is a granular activated carbon.
• the granular activated carbon (GAC) that may come within the scope of the invention will typically have a particle size ranging from 300 to 2400 ⁇ m for at least 85 to 90% by weight of the grains.
• the dimensions given are those of the equivalent diameter of the grains for dry sieving or for wet sieving.
• the adsorbent medium is implemented in at least one adsorption reactor.
• the fluid treatment unit within the scope of the invention may comprise one or more adsorption reactors, generally at least two adsorption reactors.
• the fluid to be treated within the framework of the invention can be water, in particular water to be made drinkable, but also an urban or industrial effluent (in particular leachates, which are liquid effluents from waste storage), before discharge in the natural environment or even effluents to be made drinkable (such as wastewater which is urban effluent) directly or indirectly (reuse of wastewater).
• an urban or industrial effluent in particular leachates, which are liquid effluents from waste storage
• the fluid to be treated is a liquid, such as water.
• the process of the invention is a drinking water treatment process.
• the water to be treated can be qualified as raw water, and can for example be taken from a watercourse, we will then speak of surface water, or be taken using a borehole, we will then speak of groundwater.
• the water to be treated can also be an effluent of urban origin (such as waste water otherwise called urban waste water) or industrial.
• the term “pollutant” denotes both organic matter and micropollutants.
• a micropollutant can be defined as an undesirable substance detectable in the environment at very low concentration (microgram per liter or even nanogram per litre).
• the presence of micropollutants in water is, at least in part, due to human activity (industrial processes, agricultural practices or drug and cosmetic residues).
• the micropollutant is characterized as being able, at these very low concentrations, to cause effects on living organisms due to its toxicity, its persistence and its bioaccumulation, or due to organoleptic nuisances (taste or smell, particularly relevant when is to treat water to be made drinkable).
• Micropollutants are very numerous (more than 110,000 molecules are listed by European regulations) and varied. The variety of pollutants makes it possible to classify them according to their origin, their nature, or even according to their very different chemical properties. Thus micropollutants can have a natural origin (such as compounds resulting from soil degradation, including geosmin or methylisoborneol or MIB, or bacterial residues), plant (such as algae metabolites including microcystins), animal, or human. Micropollutants can be classified according to their chemical nature, such as for example polar organic compounds, abbreviated as POC (from the English expression polar organic compounds) or organometallic compounds, abbreviated as MOC (from the English expression "metal organic compounds ").
• POC polar organic compounds
• MOC organometallic compounds
• Micropollutants can have very different chemical properties, such as detergents, metals, hydrocarbons, pesticides, cosmetics or drugs.
• the proposed fluid treatment process therefore applies in particular to compounds of the pesticide type and to the associated metabolites.
• This process also applies particularly to solvents.
• This process is also particularly applicable to pharmaceutical residues or industrial activity residues. All of these categories of pollutants or micropollutants are thus specifically concerned by the present invention.
• the treatment unit implemented in the context of the invention comprises at least one step for adsorption of pollutants contained in the fluid to be treated. This adsorption step is carried out using an adsorbent (or adsorbent medium).
• the regeneration process according to the invention is implemented on the site of use of the adsorption reactor(s), within the fluid treatment unit.
• the invention makes it possible to limit or even eliminate steps for transporting adsorbent media to be regenerated or media that has already been regenerated.
• the regeneration method comprises at least one step of removing at least part of the adsorbent medium from said at least one adsorption reactor.
• Sampling can be carried out according to any method well known to those skilled in the art.
• the removal of adsorbent media is carried out after washing the bed of adsorbent media.
• the portion of adsorbent media removed is introduced into a regeneration reactor before the regeneration step.
• part of the adsorbent medium can be sampled from all or part of the reactors, preferably from part of the adsorption reactors.
• a portion of adsorbent media can be taken from one or more of the adsorption reactors, then optionally mixed for the chemical regeneration step according to the invention.
• the regeneration method according to the invention can be implemented in one or more regeneration reactors, preferably in a single regeneration reactor.
• the portion of adsorbent medium removed represents a quantity by volume less than or equal to 50% of the volume of absorbent medium, preferably quantity by volume less than or equal to 30% of the volume of absorbent medium, preferably again a quantity by volume ranging from 1 to 10% of the volume of adsorbent medium.
• Water can be used to help the movement of the adsorbent media from the adsorption reactor to the regeneration reactor, this water can be called “motive water”.
• this motive water will preferably be taken from the fluid supply line upstream of the absorption reactor.
• the sampling step is triggered periodically according to a regeneration frequency determined in advance.
• the sampling step is triggered following a step for detecting a quality defect of the fluid to be treated downstream of the adsorption step, preferably the detection step comprises detection of a quality defect by comparison the level of pollutants or the number of pollutants between the upstream of the adsorption stage and the downstream of the adsorption stage.
• the regeneration method according to the invention comprises at least one chemical regeneration step comprising a step of bringing said part of adsorbent medium into contact with a regeneration solution comprising water and sodium hydroxide.
• the regeneration solution consists of water and sodium hydroxide.
• the mass concentration of sodium hydroxide in the regeneration solution is less than or equal to 20%, preferably less than or equal to 15%, more preferably ranges from 0.5% to 10%, or even 1.0 to 5% or 1.2 to 2.0%.
• the regeneration solution circulates through the adsorbent medium, preferably in a closed circuit.
• the regeneration solution is at a temperature less than or equal to 60°C, preferably ranging from 20 to 50°C, more preferably from 30 to 40°C.
• the water of the regeneration solution can come from the fluid to be treated, thanks to a bypass upstream of the adsorption reactor on a supply line for the fluid to be treated .
• the regeneration solution can optionally be reused for one or more other regeneration steps.
• the regeneration step can be implemented using a regeneration solution that has already been used in a previous regeneration step.
• the regeneration solution implemented in the invention is chosen from a new regeneration solution (that is to say one that has not undergone regeneration) or a regeneration solution that has already been implemented in one or more chemical regeneration steps, for example in 1 to 4 regeneration steps.
• the regeneration step can, according to a particular embodiment, be implemented using a regeneration solution having already been implemented in 1 to 4 regeneration steps.
• the ratio between the mass in kg of adsorbent media to be regenerated and the volume in liters of regeneration solution used in total ranges from 1/20 to 20/1, preferably from 1/15 to 2/1 , or even from 1/10 to 1/1.
• the adsorbent medium is rinsed using a rinsing solution, which will typically circulate through the adsorbent medium , preferably in the same direction as the regeneration solution.
• the rinse solution comprises water, preferably consists of water.
• this rinsing water will preferably be taken from the fluid supply line upstream of the absorption reactor.
• the regeneration method further comprises a second rinsing step using a second rinsing solution (different from the first rinsing solution) comprising an acid solution.
• This acid rinsing step lowers the pH.
• this acid rinsing step is followed by a water rinsing step to flush out the acid.
• the rinsing step(s) is (are) implemented by circulating the rinsing solution through the bed of adsorbent media, preferably continuously. We will then speak of dynamic rinsing.
• the chemical regeneration step further comprises a draining step at the end of the step of contact with the regeneration solution, said draining step being implemented before the rinsing step.
• the draining step lasts from 1 hour to 72 hours, preferably from 5 hours to 48 hours, more preferably from 10 hours to 36 hours.
• the regeneration solution can be removed from the regeneration reactor, for example by drainage, then the adsorbent media is maintained in the regeneration reactor.
• this draining step makes it possible to further improve the regeneration process, in particular this step allows the regeneration solution still present within the adsorbent medium to continue to regenerate the adsorbent medium.
• this small part of the regeneration solution can be kept in the regeneration reactor.
• the regeneration method according to the invention further comprises a step of electrochemical regeneration of the adsorbent medium carried out before or after or during the chemical regeneration step.
• the regenerated adsorbent media is then typically reintroduced into at least one adsorption reactor.
• the processing unit comprises several reactors adsorption
• the regenerated adsorbent medium can be introduced into the same adsorption reactor or into a different absorption reactor from the adsorbent medium removed.
• a portion of adsorbent media can be taken from several of the adsorption reactors, then mixed for the chemical regeneration step according to the invention.
• the regenerated adsorbent media will typically be reintroduced into one or more of the adsorption reactors from which the media to be regenerated was taken.
• the portion of adsorbent medium sampled has a reduction rate in at least one target pollutant ranging from 40 to 80%.
• the target pollutant can be global organic matter or a specific micropollutant.
• the regeneration method of the invention is particularly advantageous when it is implemented on a slightly used adsorbent medium.
• the regeneration method according to the invention is implemented periodically and comprises a step of controlling the frequency of regeneration as a function of the age of the adsorbent medium.
• the frequency between two regeneration cycles can be identical or different.
• the frequency of the implementation of the regeneration method according to the invention is adjusted according to the quality of the adsorbent medium, for example according to the age of the adsorbent medium.
• the adsorbent medium typically exhibits a certain reduction in these adsorption capacities due to its use as an adsorbent of pollutants. This decrease in capacity is generally approached by the notion of productivity, itself assimilated to the age of the sample.
• the age of the sample, assimilated to its productivity can thus be counted in bed volume treated (or “bed volume treated” in English, more commonly referred to as “bed volume”, abbreviated respectively as BVT and BV).
• the treated bed volume corresponds to the volume of fluid treated, more particularly water, by the adsorbent relative to the volume of the adsorbent.
• the quality of the adsorbent media is measured, typically monitored, in order to determine the age of the adsorbent media which can be defined by the actual rate of reduction in pollutant and/or by the volume of treated bed and/or by iodine number.
• the regeneration process according to the invention makes it possible to rejuvenate the adsorbent media since, after introduction of a portion of regenerated media, the bed of adsorbent media of the adsorption reactor will have a younger age than the adsorbent media taken for the regeneration.
• the measurement of the actual reduction in a target pollutant of the adsorbent media can be followed in order to determine the age of the adsorbent media.
• the portion of adsorbent media sampled has a real reduction rate of at least one target pollutant ranging from 40 to 80%.
• the target pollutant is chosen from organic matter and micropollutants.
• the target micropollutant is chosen from atrazine and atrazine derivatives (such as deisopropylatrazine, hydroxyatrazine, desethylatrazine), metolachlor, metolachlor OXA, metolachlor ESA, metazachlor OXA, chlortoluron, diuron , metaldehyde.
• This measurement of pollutant reduction can in particular be carried out directly by comparing the concentrations of pollutants upstream and downstream of a treatment of a fluid using a sample of extracted adsorbent.
• the reduction in pollutants can also be measured indirectly, by measuring a level of pollutants using, for example, a method for measuring the iodine number or even by chromatography, mass spectrometry or spectroscopy. fluorescence (in particular by HPLC, HPLC-HR or HPLC-HR & MS). This level of pollutants thus determined can then be correlated with an actual concentration of pollutants, for example using predetermined charts in particular for each pollutant.
• a real reduction in at least one pollutant ranging from 40 to 80% means that at the time t considered, 40 to 80% in concentration of said pollutant is adsorbed by the adsorbent medium having the quality of the moment t.
• the regeneration method according to the invention can thus comprise a step of measuring the (real) age of the adsorbent media and the duration before the next regeneration as well as the quantity of regenerated media reintroduced into an adsorption reactor can be determined by function of a target age to be reached for said adsorption reactor.
• the regeneration method according to the invention can thus comprise the partial replacement of the adsorbent bed with adsorbent of young age (regenerated) until the target average age determined for the adsorbent bed is obtained.
• the amount of young adsorbent to be added is for example calculated using the arithmetic mean of the amount of spent adsorbent remaining in the bed and the amount of young adsorbent added to the bed.
• the reduction in pollutants of the rejuvenated extracted adsorbent is qualified as “actual reduction in pollutants”.
• the abatement is qualified as real in that it is determined on the basis of a sample of the adsorbent actually used in the treatment process.
• the measurements of pollutant reductions of the adsorbent medium are implemented by adsorption tests in a short bed.
• Short bed adsorption corresponds to the English expression Short Bed Adsorber, abbreviated as SBA.
• the frequency of the regeneration will then be set according to the reduction rate in at least one target pollutant.
• the removal of adsorbent media to be regenerated can then be triggered as soon as the reduction rate in at least one target pollutant is 40 to 80%, preferably 50 to 70%.
• the target pollutant is chosen from organic matter and micropollutants.
• the target micropollutant is chosen from atrazine and atrazine derivatives (such as deisopropylatrazine, hydroxyatrazine, desethylatrazine), metolachlor, metolachlor OXA, metolachlor ESA, metazachlor OXA, chlortoluron, diuron , metaldehyde.
• atrazine and atrazine derivatives such as deisopropylatrazine, hydroxyatrazine, desethylatrazine
• metolachlor metolachlor OXA
• metolachlor ESA metolachlor ESA
• metazachlor OXA chlortoluron, diuron , metaldehyde.
• the actual abatement of at least one pollutant is determined by measurement and monitoring of at least one pollutant present in the fluid at the inlet of the adsorbent medium and measurement and monitoring of at least a pollutant present in the fluid at the outlet of the adsorbent medium.
• the pollutant(s) monitored can be chosen from pesticides, metabolites, solvents, industrial residues, and combinations thereof.
• the document US2019383779 describes a process for processing and monitoring pollutants online.
• Regular analyses for example by liquid or gas chromatography coupled with mass spectrometry, on the fluid at the inlet and on the fluid at the outlet can be implemented in order to compare the evolution of the content of at least one polluting.
• the difference in concentration of at least one pollutant in the fluid at the inlet and in the fluid at the outlet thus makes it possible to quantify a real reduction in the pollutant(s) monitored.
• the actual reduction in at least one pollutant can be quantified by monitoring a pilot unit (adsorption filtration column with the same adsorbent media as the industrial unit) supplied in parallel with the industrial unit, set up and dedicated specifically to monitoring the difference in fluid quality between the inlet and the outlet of this pilot bed and/or the quality of the media in this pilot bed.
• the age of the adsorbent media can be determined from the theoretical adsorption capacities for a treated bed volume.
• the target age ranges from 20,000 to 100,000 BVT, preferably from 30,000 to 75,000 BVT, more preferably from 40,000 to 60,000 BVT. It will be necessary to reset the BVT at the end of each implementation of the regeneration method according to the invention.
• the frequency of the regeneration will then be fixed according to the volume of bed treated.
• the withdrawal of adsorbent media to be regenerated can then be triggered as soon as the treated bed volume of the adsorbent media is from 20,000 to 100,000 BVT, preferably from 30,000 to 75,000 BVT, more preferably from 40,000 to 60,000 BVT.
• the measurement of the treated bed volume can be coupled with the measurement of the actual reduction rate, and possibly with the quantity of fluid to be treated.
• the iodine number can also be measured to determine the age of the adsorbent media.
• This iodine number is the quantity in milligrams of iodine adsorbed per gram of adsorbent and is used to quantify the adsorbent power of an adsorbent medium.
• the iodine number can be higher than 950 or 1000 mg/g (as for the preferred activated carbon).
• the iodine number can be less than or equal to 500 mg/g. Regeneration of the adsorbent can then lead to recovery of an iodine number preferably greater than 600 mg/g or more preferably greater than 700 mg/g.
• the frequency of regeneration will then be set according to the iodine number of the adsorbent medium.
• the removal of adsorbent media to be regenerated can then be triggered as soon as the iodine index is in the range of 500 to 800 mg/g.
• the iodine number can be determined according to the ASTM D4607 standard.
• indices can be used to determine the age of the adsorbent media to be regenerated.
• these other indices mention may be made, for example, of the methylene blue index, the phenol index, the molasses index, the tannic acid index, the monitoring of acetoxime dye. These other indices are determined by a measurement on a sample of adsorbent medium.
• the methylene blue index of the adsorbent medium is between 80 and 120 ml/g, then said adsorbent medium can be considered as an adsorbent medium of young age to be regenerated within the framework of the invention.
• the methylene blue index of the adsorbent medium can be determined according to any method known to those skilled in the art. If the acetoxime index of the adsorbent medium is between 80 and 160, then said adsorbent medium can be considered as an adsorbent medium of young age to be regenerated within the scope of the invention.
• the acetoxime index of the adsorbent medium can be determined using any method known to those skilled in the art.
• the molasses index of the adsorbent medium is between 50 and 150 mg/G, then said adsorbent medium can be considered as an adsorbent medium of young age to be regenerated within the framework of the invention.
• the molasses index of the adsorbent medium can be determined using any method known to those skilled in the art.
• the invention also relates to a process for treating a fluid in a treatment unit comprising at least one production phase, in which said at least one production phase comprises passing a fluid to be treated through a bed of media adsorbent within an adsorption reactor, said treatment method comprising at least one implementation of a regeneration method according to the invention.
• the treatment process will also include at least one shutdown phase, said at least one shutdown phase preferably comprising a sequence for washing the media and possibly putting the unit out of production and implementing the process. regeneration according to the invention.
• Said regeneration method according to the invention can be implemented during at least one production phase or a possible shutdown phase of the processing unit. Indeed, if the flow rate during the extraction of adsorbent media is not too high (for example thanks to a hydroejector), then it is possible to implement the regeneration process during a production phase.
• the adsorbent medium is chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the adsorbent medium is granular activated carbon.
• the fluid to be treated is water.
• the treatment method according to the invention further comprises at least one stopping phase in which the bed of adsorbent media is washed using a washing solution.
• the process for treating a fluid comprises a step for controlling the quality of the adsorbent medium, for example by measuring the age of the adsorbent medium.
• the treatment method according to the invention further comprises a step of measuring the age of the adsorbent medium, preferably implemented by measuring the actual reduction rate of at least one target pollutant by the adsorbent medium, and/or by measuring the bed volume treated by the adsorbent medium, and/or by measuring the iodine number of the adsorbent medium.
• the treatment method according to the invention comprises a measurement of the bed volume treated by the adsorbent medium which makes it possible to trigger the regeneration method.
• the frequency of the regeneration will then be fixed according to the volume of bed treated.
• the withdrawal of adsorbent media to be regenerated can then be triggered as soon as the treated bed volume of the adsorbent media is from 20,000 to 10,0000 BVT, preferably from 30,000 to 75,000 BVT, more preferably from 40,000 to 60,000 BVT.
• the measurement of the treated bed volume can possibly be coupled with the measurement of the actual reduction rate, and possibly with the quantity of the fluid to be treated.
• the method for treating a fluid according to the invention is implemented within the framework of an activated carbon treatment method by ascending flow, as disclosed in document FR 3003477, cited above, and to which it is referred.
• the process for treating a fluid according to the invention is implemented within the framework of a downflow activated carbon treatment process.
• the present invention can also implement, in parallel with the processing unit, a pilot unit in which the same fluid to be treated circulates in a sample of the same adsorbent medium.
• Said pilot unit will thus typically comprise at least one means for measuring the age of the adsorbent media, said means for measuring the age can thus be implemented on the adsorbent media or on the treated fluid (at the outlet of the adsorbent media of the pilot unit).
• the pilot unit will thus be very representative of the "real" processing unit and will then make it possible to determine the age of the adsorbent medium and, depending on the age, to trigger a regeneration step as defined in the invention for the processing unit according to the invention.
• the invention also relates to a fluid treatment unit for implementing the treatment method according to the invention, said treatment unit comprising: - at least one reactor for adsorption of pollutants contained in the fluid to be treated, the reactor comprising within it an adsorbent medium,
• the processing unit according to the invention further comprises at least one regeneration reactor comprising an inlet pipe for adsorbent media from said at least one adsorption reactor and an outlet pipe making it possible to reintroduce the regenerated adsorbent media in at least one adsorption reactor identical to or different from the adsorption reactor from which the absorbent medium to be regenerated originates.
• at least one regeneration reactor comprising an inlet pipe for adsorbent media from said at least one adsorption reactor and an outlet pipe making it possible to reintroduce the regenerated adsorbent media in at least one adsorption reactor identical to or different from the adsorption reactor from which the absorbent medium to be regenerated originates.
• the adsorbent medium is chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the adsorbent medium is granular activated carbon.
• the processing unit comprises at least two adsorption reactors, preferably at least three adsorption reactors. According to this embodiment with several adsorption reactors, the processing unit preferably comprises a single regeneration reactor.
• the processing unit comprises a tank intended in particular for the preparation of the regeneration solution, said tank typically comprising heating means making it possible to heat the regeneration solution before contact with the adsorbent medium to be regenerated.
• the regeneration solution preparation tank feeds the regeneration reactor.
• the processing unit according to the invention may comprise a circulation loop between the tank for preparing the regeneration solution and the regeneration reactor.
• the tank for preparing the regeneration solution can be emptied and replaced by the rinsing solution (implemented within the framework of the regeneration method according to the invention).
• the processing unit comprises means for measuring the age of the adsorbent medium.
• said means for measuring the age of the adsorbent media are chosen from among a UV spectroscope, a device for measuring dissolved organic carbon, a device for testing a short bed adsorber, and combinations thereof.
• FIG. 1 is non-limiting and illustrates one embodiment of a treatment method according to the invention:
• the water at the inlet (EE) of the adsorbent medium (GAC for example) is introduced into at least one GAC reactor 1, 2, 3, 4, passes through at least one bed of activated carbon and exits through the ES line (outlet water).
• CAG CAG
• EM motive water
• the media/regenerating solution contact time is 1 hour in a closed circuit, illustrated by circulation (Ce) and recirculation (Rc).
• the temperature of the regeneration solution is 40° C. (using a thermal resistor 10 for example) in a regeneration solution preparation device 6, and the regeneration solution consists of soda 8 at 1.7% (prepared for example with demined water 9).
• the regenerating solution can be drained towards the rejection Rj (F), or directed towards a storage tank 7 for later reuse.
• the adsorbent medium is then “drained” statically, preferably for 48 hours (time lag between 2 extractions).
• the regenerated adsorbent media in the regeneration reactor can be rinsed, preferably with site water (EE, before GAC).
• Rinsing can be carried out by dynamic contact (open circulation) by passing 2x 7 volumes of water per volume of GAC.
• the rinsing water can be evacuated towards the discharge Rj (F)
• the media in "wet” mode after the rinsing step is then reinjected (CAGr) for example via hydro-injection with water from the site (EE before GAC) into at least one adsorbent reactor 1, 2, 3, 4, identical to or different from the adsorption reactor from which the medium is taken in step (B).
• CAGr reinjected
• Regeneration solutions are obtained by diluting a 35% sodium hydroxide solution. 100 g of CAG to be regenerated are introduced with 800 mL of the solution prepared in a 1 L bottle (except for the example "effect of the mass ratio of CAG/volume of regeneration solution" where the quantity of solution is 200, 500 or 800mL). The bottles are placed in a rotating agitator where they are mixed at a speed of approximately 15 revolutions per minute.
• 100 g of GAC is weighed.
• 100 g of drained GAC corresponds to between 100 and 125 mL depending on the degree of humidity of the GAC.
• Circulating rinse the GAC is placed in a column with water.
• the water is pumped from the top of the column and then reinjected into the bottom of the column (or evacuated) via a peristaltic pump.
• the pump is configured to deliver a flow corresponding to a speed equivalent to that of the pilot (15 m/h).
• the SBA Short Bed Adsorber Adsorber
• GAC new, used or regenerated is placed in cartridges through which passes raw water spiked with micropollutants (feed matrix).
• the inlet water and the outlet water of each cartridge is analyzed to determine the reduction of micropollutants by the GAC, thus characterizing the adsorption capacities of the tested GAC.
• the peristaltic pump allows the passage of water at a fixed speed for a targeted contact time in the column, in ascending or descending flow.
• the raw water entering the SBA is spiked at 2.5 pg/L for micropollutants, such as pesticides or metabolites: Metolachlor OXA Metazachlor ESA, Alachlor OXA, Metolachlor ESA.
• micropollutants such as pesticides or metabolites: Metolachlor OXA Metazachlor ESA, Alachlor OXA, Metolachlor ESA.
• the water is transferred to the GAC cartridges, and is analyzed as they enter and exit. For each sample, the concentration of micropollutants and organic matter (COD and UV absorbance) is measured.
• the concentrations of water entering and leaving the control media (GAC before regeneration, partially saturated for the adsorption of certain micropollutants) and the reference media (new GAC) are also analyzed to determine the abatement rate, the coefficient of efficiency (RE) and maximum regeneration efficiency coefficient (RE max) for micropollutants and organic matter.
• the 4 micropollutants mentioned were chosen because they are poorly adsorbable, i.e. they are associated with breakthroughs of GAC filters for productions or media age between 50,000 and 100,000 VV.
• Organic matter is not harmful in itself but has many consequences on the treatment and appearance of water. It is, by reaction with oxidants (ozone, chlorine, etc.), the origin of disinfection by-products, it gives color to the water and is likely to saturate the filtering media.
• oxidants ozone, chlorine, etc.
• MO concentration of the order of milligrams per litre
• the OM is monitored by UV spectroscopy analysis (at 254 nm) and measurement of DOC (Dissolved Organic Carbon). The higher the UV and COD values, the more MO is present.
• the COD is measured after passing through a filter (TOC-meter).
• the regeneration efficiency recovery coefficient (RE) was chosen to quantify the performance of the regeneration of GAC, vis-à-vis the adsorption of OM and micropollutants monitored in the project. It is calculated from the reduction of the compound monitored, on the regenerated CAG and on the control CAG. These quantities are therefore specific to each micropollutant (A).
• A with Co the concentration of the compound at the inlet of the CAG filter and C the concentration of the compound at the outlet of the GAC filter.
• the regeneration efficiency coefficient RE AQAG REGEWERE with A the abatement of a
• a compound WITNESS CAG A compound WITNESS CAG.
• a regeneration step as described in this example was implemented for 7 hours, with a 1.7% concentrated sodium hydroxide solution using either demineralized water or borehole water (water from the site to be treated ).
• the efficiency coefficient RE has been determined for different pollutants and is shown in [Fig. 2]
• the regeneration solution implemented in the invention comprises water from the treatment site, for example fluid to be treated in the case where the fluid to be treated is water, such as borehole water.
• a regeneration step as described in this example was implemented for 7 hours, with a concentrated sodium hydroxide solution at 1.7% and 15.2%.
• the efficiency coefficient RE has been determined and is shown in [Fig. 3] The results of FIG. 3 show that there is a very small difference between a concentration of 1.7% and a concentration of 15.2%. Effect of the mass ratio of GAC/volume of regeneration solution
• a regeneration step as described in this example was implemented with 100 g of CAG and different volumes of 1.7% regenerating solution: 200 ml_, 500 ml_ and 800 ml_.
• the efficiency coefficient RE was determined and is shown in [Fig. 4]
• the results of FIG. 4 show that the volume of regenerating solution has little influence on regeneration.
• the process has the advantage of being able to be implemented with a limited quantity of regeneration solution, thus reducing reagents and rejects.
• a regeneration step as described in this example was implemented with different sodium hydroxide/GAC contact times under stirring), with a regenerating solution at
• rinsing water is site water (drilling water) originating from the fluid to be treated.
• the inventors discovered that a draining step (waiting time) before the rinsing step or the SBA test could be implemented in order to improve the efficiency of the regeneration.
• a rinsing step was implemented immediately after a 1 hour regeneration with a 1.7% regenerating solution or a rinsing step was implemented 24 hours after a 1 hour regeneration with a 1.7% regenerating solution.
• the efficiency coefficient RE was determined and is shown in [Fig. 10] where the result without rinsing with an immediate SBA is also indicated. The results of FIG. 10 show that a draining step before rinsing step makes the regeneration more efficient.
• the invention thus proposes an effective regeneration process, implementing a reduced quantity of reagents and being able to use the water from the site as a rinsing solution and/or in the regeneration solution.
• the sodium hydroxide concentration may be less than 2% in the regeneration solution, in particular when the regeneration process includes a draining step (waiting) before rinsing.

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