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
  • 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
  • B01D—SEPARATION
  • B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D15/00—Separating processes involving the treatment of liquids with solid sorbents; Apparatus therefor
  • B01D15/08—Selective adsorption, e.g. chromatography
  • B01D15/10—Selective adsorption, e.g. chromatography characterised by constructional or operational features
  • B01D15/20—Selective adsorption, e.g. chromatography characterised by constructional or operational features relating to the conditioning of the sorbent material
  • B01D15/203—Equilibration or 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
  • C02F1/28—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
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/28—Treatment of water, waste water, or sewage by sorption
  • C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
• • 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
  • C02F1/285—Treatment of water, waste water, or sewage by sorption using synthetic organic sorbents
• • 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
  • C02F1/286—Treatment of water, waste water, or sewage by sorption using natural organic sorbents or derivatives thereof
• • 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
  • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
• • 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
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/32—Hydrocarbons, e.g. oil
• • 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
  • C02F2101/36—Organic compounds containing halogen
• • 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

• TITLE METHOD FOR DETERMINING THE REMAINING CAPACITY OF AN ADSORBENT AND METHOD FOR TREATMENT OF A FLUID USING THE SAID
• 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 the management and optimization of this treatment step by proposing a method making it possible to determine the remaining capacity of an adsorbent medium and a method for treating a fluid by adsorption on an adsorbent medium using implements the method for determining the remaining capacity of the adsorbent media.
• 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 using this type of treatment facility seek to determine the adsorption capacity of the adsorbent media in order to be able to optimize renewal or regeneration operations.
• Semi-industrial pilot tests can be set up to determine the adsorption capacity of a medium. Nevertheless, these semi-industrial pilot tests are very long and costly and must be carried out on each treatment unit (adsorbent media, fluid quality, contact time). The method of the invention makes it possible to dispense with these semi-industrial pilot tests.
• Document EP 3 153475 A1 describes the application of a dose of carbon (micro grains) according to the reduction in UV absorbance followed online, associated beforehand with a reduction in the desired micropollutant, established for activated carbon, water and the micropollutant(s). The process described in this document does not take into account the accumulation of micropollutants in the adsorbent media over time.
• Park Minkyu et al. and Zusman Ofri B et al. do not describe a method including an adjustment step as defined in the present invention. Thus, these documents do not describe either the operational control of adsorbent media or the determination of the remaining capacity of an adsorbent media at a time t in a processing unit.
• the invention relates to a method for determining the remaining capacity of an adsorbent medium in a fluid treatment unit, said treatment comprising passing a fluid through an adsorbent medium, said method comprising at least the following steps : a) measurement of the dissolved organic carbon content of the fluid and determination of the contact time on an empty bed on the adsorbent medium, b) determination of at least one target pollutant, c) determination of the breakthrough curves of at least two reference pollutants, said breakthrough curves being determined for the dissolved organic carbon content and the contact time on an empty bed measured in step a), d) adjustment of the breakthrough curves determined in step c) from the actual operating conditions of the treatment unit, e) determination of the remaining capacity of the adsorbent medium from the breakthrough curves adjusted at the end of step d) for the target pollutant(s) .
• the adjustment step is implemented with a step chosen from among: implementation of an empirical technique, implementation of a short-bed adsorber test, implementation of a medium-bed adsorber test, implementation of a real pilot test.
• the adjustment step is implemented using a short-bed adsorber test including a step of sampling at least a portion of the adsorbent media from the processing unit.
• the method of the invention is implemented periodically, it being understood that the adjustment step can optionally be implemented with different techniques for each implementation.
• the method of the invention further comprises, upstream of step c), a step of preparing at least one breakthrough curve for said at least two reference pollutants, and this for at least least two dissolved organic carbon contents and two empty bed contact time values.
• the step of preparing at least one breakthrough curve for at least two reference pollutants is implemented by at least one technique chosen from among a pilot breakthrough test, or by mini-column ( RSSCT) or among a fixed-bed modeling resulting from isothermal and kinetic type adsorption tests.
• RSSCT mini-column
• the method further comprises a step of comparing said target pollutant with said pollutants benchmark for breakthrough curves.
• the comparison step comprises at least one step of chromatographic analysis of the fluid to be treated, said fluid possibly being concentrated beforehand, in order to determine the elution times of the target pollutant and of said at least two reference pollutants of the curves of breakthroughs.
• the method further comprises a step of determining the breakthrough curve of the target pollutant from its comparison with the breakthrough curves of the reference pollutants.
• the step of measuring the dissolved organic carbon content of the fluid to be treated is implemented using a measuring unit of the processing unit, said measuring unit preferably being selected from a UV spectrometer, a chromatography unit, a mass spectrometry and a fluorescence spectroscope.
• the invention also relates to a method for treating a fluid in a treatment unit comprising at least one adsorbent medium, said treatment method comprising: i. passing the fluid through at least one adsorbent medium, ii. the implementation of the method for determining the remaining capacity of said adsorbent medium according to the invention making it possible to determine the remaining capacity of the adsorbent medium, iii. determining the duration before the next renewal or regeneration of at least a part of the adsorbent media and/or determining the quantity of adsorbent media to be renewed or regenerated according to the remaining capacity of the media determined in step ii , iv. renewing or regenerating at least part of the adsorbent medium according to the duration and/or the quantity of adsorbent medium determined in step iii.
• the adsorbent medium is chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the medium adsorbent is a granular activated carbon, and/or the fluid to be treated is chosen from water, an urban effluent, an industrial effluent, preferably the fluid to be treated is water.
• 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 comprising within it an adsorbent medium
• control unit making it possible to determine the duration before the next renewal or regeneration of at least part of the adsorbent medium and/or to determine the quantity of adsorbent medium to be renewed or regenerated
• control means making it possible to actuate the renewal and/or the regeneration of at least part of the adsorbent medium.
• the processing unit according to the invention further comprises a unit for measuring the actual reduction in pollutants from the adsorbent medium, preferably a short-bed measurement unit preferably comprising beds of lower volume or equal to 100mL.
• 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 invention makes it possible to determine the remaining capacity of an adsorbent medium, such as activated carbon, in a unit for processing a fluid, by a method that is simple, rapid, transposable to different processing units and reliable.
• the determination method of the invention has the advantage of taking into account the reality of an on-site treatment unit, including the history of the adsorbent media (for example conditions of implementation of the media in the adsorbent media filter : speed, contact time, evolution of organic matter concentrations) as well as the history of the pollution flow (for example the pollutants in the fluid supplying the unit).
• FIG. 1 represents several pollutant breakthrough curves, for a given type of adsorbent media, and for two COD contents and two EBCT contact times.
• FIG. 2 represents, for a COD content, an EBCT contact time and a given type of adsorbent media, the breakthrough curves for four pollutants.
• FIG. 3 represents the abatement measurements by an SBA test at a given time (one volume of fluid passed) for the four pollutants in [Fig. 2]
• FIG. 4 represents the breakthrough curves adjusted at the end of the SBA test.
• FIG. 5 represents the breakthrough curve of a target pollutant, depending on the current situation (volume of past fluid).
• FIG. 6 represents an SBA test machine.
• FIG. 7 represents a block diagram of a determination method according to the invention.
• the invention relates to a method for determining the remaining capacity of an adsorbent medium implemented in a fluid treatment unit, said treatment comprising passing a fluid through an adsorbent medium, said method comprising at least the following steps: a) measurement of the dissolved organic carbon content of the fluid and determination of the contact time on an empty bed on the adsorbent medium, b) determination of at least one target pollutant, c) determination of the breakthrough curves of at least two pollutants (known as "reference pollutants"), said breakthrough curves being determined for the content of dissolved organic carbon and the contact time on an empty bed measured in step a), d) adjustment of the determined breakthrough curves in step c) from the actual operating conditions of the processing unit, e) determination of the remaining capacity of the adsorbent medium from the breakthrough curves adjusted at the end of step d) for the at minus one pollutant determined in step b).
• 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 from 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 wastewater 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 liter).
• 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 nature, such as, for example, polar organic compounds, abbreviated as POC (polar organic compounds) or organometallic compounds, abbreviated as MOC (metal organic compounds).
• POC polar organic compounds
• MOC metal organic compounds
• Micropollutants can have very different chemical properties, such as detergents, metals, hydrocarbons, pesticides, cosmetics or drugs.
• the fluid treatment method proposed therefore applies in particular to compounds of the pesticide type and to the associated metabolites. This process also applies particularly to solvents. This method also applies particularly to pharmaceutical residues or to 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 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 used in the context of the invention, including biochar.
• Biochar is a composition comprising pyrolyzed biomass biochar, biomass biochar produced by hydrothermal carbonization, or a combination thereof.
• Biomass can be selected from agricultural crop waste, forestry waste, algae, animal or human waste, industrial waste, municipal waste, anaerobic digester waste, plant material grown for biomass production, or a combination of these.
• 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 cations ferrous or ferric, 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, biochar9)
• GAC granular activated carbon
• the method of the invention can be implemented with different types of CAG.
• 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 processing unit will comprise one or more adsorbent media, for example one or more activated carbon filters, in particular GAC.
• a fluid passes through one or more adsorbent media on which the pollutants present in the fluid will be adsorbed.
• the treatment unit falling within the scope of the invention may be a drinking water production unit or a municipal or industrial wastewater treatment unit, for discharge into the natural environment or reuse.
• the treatment unit is a drinking water production unit.
• the treatment process will include phases called “production phases” during which the fluid circulates through the adsorbent media and phases called “shutdown phases” during which the fluid does not circulate through the adsorbent media.
• the processing unit may include one or more adsorbent media filters.
• the determination method according to the invention may be implemented for each adsorbent media filter of the processing unit, either simultaneously or at different times.
• the adsorption capacity depends on several parameters, in particular the volume of fluid to be treated, the quality of the fluid to be treated, or the contact time between the adsorbent media and the fluid to be treated.
• two beds of adsorbent can have different pollutant reduction capacities, depending on the actual variations in concentrations and the nature of the pollutants actually treated by each of these adsorbent beds.
• the theoretical adsorption capacities for a bed volume treated are generally determined pollutant by pollutant, but without taking into account the competition between organic matter and micropollutants for the adsorption sites or even the competition of the micropollutants with each other (also designated by the expression “cocktail effect”). For example, highly adsorbable micropollutants will tend to saturate the adsorption sites before less adsorbable micropollutants have been adsorbed.
• the competition of pollutants for adsorption sites is particularly present for compounds with a low affinity for adsorption (small polar molecules) such as pesticide metabolites.
• Theoretical determinations of adsorption capacities as a function of the bed volume treated may therefore tend to overestimate the remaining adsorption capacities of a real adsorbent bed.
• the method of the invention makes it possible to determine the remaining capacity of an adsorbent medium. It takes into account the real context of the treatment unit in order to avoid this overestimation and to take into account the evolution of the parameters, in particular the type of adsorbent media, the volume of fluid to be treated, the quality of the fluid to be process, or contact time.
• the determination method according to the invention is implemented when the processing unit has already started to operate, and it can be implemented periodically, for example every 3 to 12 months or depending on the volume. of fluid treated by an adsorbent medium.
• the remaining capacity of an adsorbent media makes it possible to predict the production time of this adsorbent media before the breakthrough of the target pollutant(s).
• the remaining capacity is evaluated by determining the limit VV, VV from which the breakthrough of the pollutant is detectable.
• the VV corresponds to the ratio between the volume of fluid passed and the volume of adsorbent media of the treatment unit.
• the method of the invention comprises a step of measuring the dissolved organic carbon (DOC) content of the fluid and determining the empty bed contact time (EBCT for “empty bed contact time”) on at least one adsorbent medium of the 'processing unit.
• DOC dissolved organic carbon
• EBCT empty bed contact time
• the volume of fluid passed and the volume of adsorbent media of the processing unit are measured in order to know the VV (ratio between the volume of fluid passed and the volume of adsorbent media), and the content in COD of the fluid and the contact time EBCT are determined on the processing unit.
• the empty bed contact time is typically determined by measuring the inflow, then calculating the ratio between the volume of adsorbent media and an average of the inflow.
• the measurement of the DOC content can be carried out continuously or semi-continuously.
• a semi-continuous measurement means a measurement at regular intervals, for example once a week or once a month.
• the pollutant content of the fluid is also determined at this stage, at the same time as the COD content.
• Pollutants designate both organic matter and micropollutants.
• the measurement of the COD content and, where appropriate, of pollutants in the fluid can be carried out by various methods, known to those skilled in the art, for example by at least one method chosen from UV spectrometry (for example at 254 nm), chromatography, mass spectrometry and fluorescence spectroscopy (also referred to as 3D fluorescence).
• the measurement method can be a method of high-performance liquid chromatography (also designated by the English expression high-performance liquid chromatography, abbreviated as HPLC), in particular with a high resolution (designated by the English expression high-performance liquid chromatography with high resolution, abbreviated as HPLC-HR) and even more particularly coupled with mass spectrometry (corresponds to the English expression mass spectrometry, abbreviated as MS).
• HPLC high-performance liquid chromatography
• MS mass spectrometry
• This step a) can be implemented by a measurement unit making it possible to determine the dissolved organic carbon content of the fluid to be treated, said measurement unit then being located upstream of the adsorbent medium, and preferably being chosen from a UV spectrometer , a chromatography unit, mass spectrometry and a fluorescence spectroscopy device.
• the determination method of the invention also comprises a step for determining at least one target pollutant.
• the target pollutant(s) will be chosen from micropollutants, preferably the most restrictive micropollutants on the site.
• the remaining capacity of the adsorbent media will typically be determined based on this target pollutant and the prediction of its behavior.
• the method of the invention comprises a step of measuring the pollutant content of the fluid to be treated, in particular of the target pollutant(s). This measurement can be implemented continuously or semi-continuously. The measurement of the pollutant content is preferably implemented simultaneously with the measurement of the COD content (step a)).
• 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 method of determination can be implemented by a control unit of the processing unit.
• the determination method of the invention comprises at least one step of determining the breakthrough curves of at least two pollutants corresponding to the dissolved organic carbon content and to the contact time on an empty bed measured in step a).
• breakthrough curves are determined for at least two pollutants.
• the breakthrough curves are determined for at least three pollutants, preferably for at least four pollutants.
• the breakthrough curves are determined for the organic matter and for at least two micropollutants, preferably at least three micropollutants.
• the [Fig. 1] illustrates breakthrough curves for two COD and two EBCT contents, for four pollutants.
• the processing unit falling within the scope of the invention may include a database with breakthrough curves for more than 2 COD contents and more than 2 EBCT.
• Each breakthrough curve represents the C/CO ratio of a pollutant as a function of the BV (“Bed volume”, corresponding to the VV “volume volume”, for example volume of water per volume of GAC), CO representing the concentration of pollutant in the fluid at the inlet of the adsorbent media and C representing the concentration of pollutant in the fluid at the outlet of the adsorbent media.
• At least two breakthrough curves are integrated into a database for at least two pollutants.
• a breakthrough curve is prepared for at least 3 pollutants, more preferably at least 4 pollutants, advantageously from 5 to 10 pollutants.
• breakthrough curves can be prepared and integrated into a database of the processing unit. They are also referred to as “abacus” and the pollutants whose breakthrough curve is plotted are called “reference pollutants”. Typically, molecules can be classified into three categories:
• Moderately adsorbable having a medium breakthrough (1 £ log Kow £ 3), Strongly adsorbable: having a long breakthrough (log Kow > 3).
• the reference pollutants comprise at least two micropollutants (called “reference micropollutants”), preferably chosen from micropollutants belonging to at least two different categories of adsorbability.
• the charts will be plotted for at least one "poorly adsorbable" micropollutant and for at least one "highly adsorbable” micropollutant. This makes it possible to cover the micropollutants likely to be on the treatment unit in order to have a more precise and more accurate determination of the remaining capacity.
• the database breakthrough curves can be obtained by different methods, preferably according to a deterministic model: for example isothermal and adsorption kinetics, then modeling in a fixed bed or by pilot breakthrough test called RSSCT test (for " Rapid Small Scale Column Test”)
• RSSCT test for " Rapid Small Scale Column Test”
• the isothermal and kinetic model of adsorption, then modeling in a fixed bed has the advantage of being implemented quickly, compared to other models.
• these models will be implemented with adsorbent media similar or even identical to the (new) adsorbent media of the treatment unit and with a fluid matrix, typically a water matrix, similar to that of the treatment unit , but doped with micropollutant(s) in order to define the breakthrough of said micropollutant(s).
• the model of the isotherm and adsorption kinetics can for example be that of Freundlich, Langmuir, Elovich or Temkin. This list is not exhaustive, other models may be implemented.
• the fixed-bed modeling of the kinetics and the isotherm can be that of homogeneous surface diffusion (HSDM for "Homogenous Surface Diffusion Model” or pore surface diffusion (PSDM for "Pore Surface Diffusion Model”).
• HSDM homogeneous surface diffusion
• PSDM Pore Surface Diffusion Model
• RSSCT test for “Rapid Small Scale Column Test”
• RSSCT test for “Rapid Small Scale Column Test”
• This test makes it possible to draw a real breakthrough curve, since in this test, the fluid matrix of the treatment unit continuously feeds mini-columns of crushed adsorbent media with intermittent or continuous doping of micropollutants.
• the determination method according to the invention may comprise a preliminary step of preparing the breakthrough curves determined in step c) for at least two pollutants, for at least two DOC (Dissolved Organic Carbon) contents and at least two times EBCT contact details.
• Breakthrough curves can be prepared by any of the methods described above.
• the (reference) pollutants are chosen from organic matter and micropollutants.
• the reference micropollutants are chosen from atrazine and atrazine derivatives (such as deisopropylatrazine, hydroxyatrazine, desethylatrazine), metolachlor, metolachlor OXA, metolachlor ESA, metazachlor OXA, chlortoluron, diuron, metaldehyde.
• the adsorbent medium In order to accelerate the adsorption phenomena, the adsorbent medium is generally crushed for the preparation of these breakthrough curves and the fluid can change during the operating time of the treatment unit, for example according to the seasons. Consequently, these models do not always reflect the state of the media at time t and are generally optimistic since the crushed media will have more adsorption sites than the uncrushed media implemented in the processing unit.
• step a) makes it possible to determine the desired breakthrough curves, corresponding to the COD content and the EBCT contact time.
• the [Fig. 2] corresponds to the breakthrough curves for a given COD content and a given EBCT contact time, for a given adsorbent medium.
• the breakthrough curves of four pollutants P1, P2, P3, and P4 are determined in this [Fig. 2]
• P1 can represent the organic way and P2, P3 and P4 are three different micropollutants.
• the determination method of the invention comprises an additional step.
• the method further comprises a step of comparing said target pollutant with said pollutants of the breakthrough curves. The comparison step makes it possible to predict the behavior of the target pollutant.
• the comparison step comprises at least one step of chromatographic analysis of the fluid to be treated, said fluid possibly being concentrated beforehand, in order to determine the elution times of the target pollutant and of at least two pollutants of the curves of breakthroughs.
• the chromatographic analysis step is preferably a liquid phase chromatography analysis coupled to mass spectrometry (HPLC-MS)
• a prior concentration step can be implemented.
• a concentration step a solid phase extraction (SPE) can be implemented upstream of the chromatography step.
• the target pollutant has an elution time between the elution time of pollutants P2 and P3, then it means that the target pollutant will have a breakthrough between that of P2 and P3 and its breakthrough curve will then be placed on the breakthrough curve between the curves of P2 and P3.
• Step c) can be implemented using a database of the processing unit, said database including in particular breakthrough curves.
• the processing unit may optionally also comprise an analysis unit making it possible to compare pollutants.
• the analysis unit comprises at least one chromatography unit, preferably column chromatography.
• a concentration unit for example a solid phase extraction (SPE) unit, allowing the pollutants to be concentrated may be present in the treatment unit, generally upstream of the analysis unit.
• SPE solid phase extraction
• breakthrough curves of the pollutants typically including the breakthrough curve for each target pollutant, for a COD content and an EBCT contact time
• said breakthrough curves are adjusted (or readjusted).
• This adjustment is implemented based on the actual operating conditions of the processing unit, in particular the adsorbent media.
• Actual operating conditions of the processing unit may include:
• the state or quality at time t of the adsorbent media (during the implementation of the method for determining the remaining capacity of the adsorbent media), including in particular the actual reduction rate of the adsorbent media at instant t (for example, the result of a short bed adsorber test called the SBA test (for “Short Bed Adsorber”), - the quality of the fluid at the outlet of the adsorbent medium, it being understood that it can be monitored continuously, the data being able to be collected in a database of the processing unit,
• This adjustment can be implemented for example by a technique chosen from: an empirical technique, or a short bed adsorber test called SBA test (for “Short Bed Adsorber”).
• the empirical technique is based on the history of the treatment unit and all the analytical data recorded during the operation of the treatment unit and in particular of the adsorbent media.
• This analytical data is typically stored in a database.
• the analytical data are the evolution of the content of micropollutants and pollutants at the inlet and at the outlet of the adsorbent media, taking into account the renewal and regeneration cycles of the adsorbent media.
• this empirical method is particularly well suited when breakthrough curves have already been prepared for several pollutants and several COD contents and several EBCT contact times or when the treatment unit has already been running for a certain time, for example for at least 6 months or even at least 12 months.
• the SBA test is then implemented at the chosen time t, from a sample of fluid and adsorbent media on the processing unit whose remaining capacity is to be determined.
• the sampled fluid is spiked with reference pollutants from the breakthrough curves and the target micropollutant(s) on the site studied if they are not present in the breakthrough curves.
• the extraction of a sample from the adsorbent media for the implementation of the SBA test is typically implemented during a shutdown phase of the fluid treatment process.
• the pollutant reduction rate can be determined by the SBA test.
• the abatement rate by the SBA test is determined for as many pollutants as there are reference pollutants in the breakthrough curves determined in step c).
• the breakthrough curves can be adjusted.
• FIG. 6 illustrates an SBA test machine 60 with 8 filtration cartridges 62 filled with adsorbent of the extracted sample. It should be noted that the determination method of the invention can be implemented several times, at regular intervals on the same adsorbent medium taken from the processing unit, and that it will be possible to use for a first implementation the SBA test and for another implementation, another adjustment technique, such as an empirical technique.
• the SBA test technique will be the preferred technique. Indeed, it has the advantage of taking into account the adsorbent medium and the fluid to be treated in the treatment unit, unlike empirical techniques.
• step c) The breakthrough curves determined in step c) are adjusted (or readjusted) to coincide with the pollutant reduction rates determined by the SBA test.
• FIG. 3 shows the reduction rates for pollutants P1, P2, and P3 obtained by the SBA test at time t (corresponding to a volume of fluid past 40,000 BV) with the vertical dashed line.
• P4 C/C0 is 0%.
• This adjustment step can be implemented using a control unit of the processing unit.
• the determination method according to the invention comprises a step in which the remaining capacity of the adsorbent medium (also called VV limit) is determined from the breakthrough curves adjusted at the end of step d).
• the limit VV will be determined from the breakthrough curve of the micropollutant present in the sampled fluid having the fastest breakthrough. This could be the target pollutant from step d).
• the VV limit will generally be determined based on the desired limit for the C/C0 ratio. Depending on the processing unit and the sector concerned, the operator can choose a VV limit such that C/C0 is less than or equal to 70%, even less than or equal to 60% or even less than or equal to 50% .
• the [Fig. 5] shows a comparison between the current situation (past bed volume) and the breakthrough curve of the target pollutant (PC). The target pollutant was determined (in accordance with step b) of the method of the invention).
• the determination method of the invention can be repeated, for example, when the measurement of the COD content of the fluid to be treated calls into question the determination of the breakthrough curves during step c).
• the determination method can be implemented again by again determining the breakthrough curves with the new DOC content, by determining at least one target pollutant (this may be the same target pollutant or a different target pollutant than that during the previous implementation of the determination method), by adjusting the breakthrough curves preferably on the basis of an empirical method based on, for example, a previous adjustment, and then determining the remaining capacity of the adsorbent media from the new adjusted breakthrough curves.
• the [Fig. 7] illustrates an embodiment of the determination method of the invention.
• the first step of the method comprises a step for measuring the COD content 11 and a step 11' for determining at least one target pollutant.
• Step 12 consists in determining the breakthrough curves for the given COD content (also considering the contact time EBCT).
• step Q1 consists in asking whether the target pollutant is present on the breakthrough curves of step 12. According to the embodiment illustrated in this [FIG.
• step 12 in which the target pollutant is placed on the breakthrough curves of step 12.
• This step 12' can for example be a chromatographic analysis making it possible to compare the elution times of the pollutants already present on the breakthrough curves and the target pollutant. The inventors have discovered that elution times are linked to the treatability of pollutants, in particular micropollutants.
• the method comprises a step 13 for adjusting these curves taking into account the actual operation of the processing unit, in particular taking into account the behavior of the adsorbent medium on the processing unit and processing unit history.
• the remaining capacity of the adsorbent media is determined in step 15. Knowing the remaining capacity of the adsorbent media thus makes it possible to determine the duration before the next renewal or the next regeneration of the adsorbent media and/ or to determine the quantity of adsorbent media to be renewed or regenerated in step 16.
• the determination method according to the invention makes it possible to anticipate the schedule for renewal and/or regeneration of the adsorbent filters, without waiting for a breakthrough, which would affect the quality of the treated fluid.
• the determination method according to the invention also makes it possible to have an operating strategy for the processing unit, for example on the number of filters in operation and/or on the quantity of adsorbent media to be renewed or regenerated.
• the invention also relates to a method for treating a fluid comprising: i. passing the fluid through at least one adsorbent medium, ii. the implementation of the method for determining the remaining capacity of said adsorbent medium according to the invention making it possible to determine the remaining capacity of the adsorbent medium, iii. the determination of the duration before the next renewal or regeneration of at least a part of the adsorbent media and/or the determination of the quantity of adsorbent media to be renewed or regenerated according to the remaining capacity of the media determined in step N , iv. renewing or regenerating at least part of the adsorbent media according to the duration and/or the quantity of adsorbent media determined in step iii.
• the renewal of an adsorbent media filter can be total or partial. Indeed, in a used adsorbent media filter, it is possible to incorporate new or regenerated media and remove only part of the used media.
• a new adsorbent media will be a media that has not yet undergone an adsorption step.
• Used adsorbent media will be media that has undergone at least one adsorption step.
• a regenerated media or adsorbent corresponds to an adsorbent which, after cycles of use as an adsorbent, has been treated, for example thermally or chemically, to regain adsorption capacities close to that of the new adsorbent.
• the regenerated adsorbent can however present more limited adsorption capacities than the same adsorbent when new.
• These more limited adsorption capacities after regeneration can for example be characterized by the iodine adsorbance index index, or iodine index.
• 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 measurement of the iodine index can in particular be carried out according to the protocol standardized by the ASTM D4607 - 14 standard.
• the iodine index can be greater than 950 or 1000 mg/g (such as than for the preferred activated carbon).
• the iodine number can be less than 400 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 regeneration can be carried out off-site, in particular by the supplier of the adsorbent, in particular, using reactivation such as a heat treatment above 800°C, in the case of an adsorbent in the form of charcoal.
• the iodine number obtained for such regeneration can then be greater than 800 mg/g or even greater than 850 mg/g.
• the regeneration can also be carried out on the site of the treatment installation by chemical treatment or heat treatment, in particular at temperatures below the reactivation at 800° C. This on-site regeneration advantageously makes it possible to recover part of the adsorption capacities (iodine index between 600 and 800 mg/g) without necessarily requesting a more restrictive off-site reactivation.
• the treatment process can be implemented in such a way as to have a constant age of the adsorbent media to ensure permanent efficiency in the elimination of pollutants. This can be made possible by partial renewal of the adsorbent, according to a schedule determined using the determination method of the invention.
• the calendar can be updated each time the invention determination method is implemented.
• the adsorbent medium is chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the medium adsorbent is granular activated carbon.
• the fluid to be treated is chosen from water, an urban effluent, an industrial effluent, preferably the fluid to be treated is water.
• the invention also relates to a fluid treatment unit for implementing the fluid 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 comprising within it an adsorbent medium, - a unit of measurement to determine the dissolved organic carbon content of the fluid to be treated (upstream of the adsorbent media),
• control unit making it possible to determine the duration before the next renewal or regeneration of at least part of the adsorbent medium and/or to determine the quantity of adsorbent medium to be renewed or regenerated
• control means making it possible to actuate the renewal and/or the regeneration of at least part of the adsorbent medium.
• the processing unit according to the invention further comprises a database making it possible to store data such as the breakthrough curves, the dissolved organic carbon contents, and/or the contact time on an empty bed of said at least least one adsorption reactor.
• the processing unit further comprises a unit for measuring the actual abatement of pollutants from the adsorbent medium, preferably a short bed measurement unit (short bed adsorber) preferably comprising beds of volume less than or equal to 100mL, more preferably less than or equal to 50ml_, even more preferably less than or equal to 20ml_.
• a short bed measurement unit short bed adsorber
• the adsorption reactor comprises within it an adsorbent medium chosen from granular activated carbon, anion exchange resin, biomaterials, molecularly imprinted polymers and mineral materials, preferably the medium adsorbent is granular activated carbon.
• the unit of measurement making it possible to determine the content of dissolved organic carbon is chosen from among a UV spectrometer, a chromatography unit, a mass spectrometry and a fluorescence spectroscopy device.
• the processing unit according to the invention further comprises an analysis unit making it possible to compare pollutants.
• the analysis unit comprises at least one chromatography unit, preferably column chromatography.
• a concentration unit for example a solid phase extraction (SPE) unit, allowing the pollutants to be concentrated may be present in the treatment unit, generally upstream of the analysis unit.
• SPE solid phase extraction
• the unit(s) of measurement and, if applicable, the analysis unit is (are) configured to send data (for example, results of COD measurements and, if applicable, chromatographic analysis) to the control and/or to the database of the processing unit.
• data for example, results of COD measurements and, if applicable, chromatographic analysis
• control unit also makes it possible to plot breakthrough curves for the pollutants, called “reference pollutants”, implemented during step c) of the determination method of the invention.
• the control unit can implement an isothermal and kinetic model of adsorption, then modeling in a fixed bed.
• processing unit may comprise a pilot breakthrough test device called the RSSCT test (for “Rapid Small Scale Column Test”) allowing the preparation of reference pollutant breakthrough curves.

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• 2021
  • 2021-04-22 FR FR2104220A patent/FR3122104B1/fr active Active
• 2022
  • 2022-04-21 WO PCT/EP2022/060533 patent/WO2022223682A1/fr not_active Ceased
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