Adsorbents with high volumetric iodine values ​​and high volumetric molasses values ​​for removing PFAS from fluids and methods of making and using the same

Abstract

The present disclosure provides adsorbents and adsorbents that improve the adsorption of per- and polyfluoroalkyl substances (PFAS). The adsorbents and adsorbents have a microstructure that effectively adsorbs PFAS, as shown by a combination of a high volumetric iodine number and a high volumetric molasses number. Further provided are methods of manufacture and methods of use.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 051,637, filed on July 14, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure describes adsorbents with improved performance in removing per- and polyfluoroalkyl substances, including but not limited to PFOA, PFOS, and similar compounds, from liquids and gases. Background Art

[0004] Per- and polyfluoroalkyl substances (PFAS) are a group of compounds including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and compounds produced by the gENX process, such as 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propionate and heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether. Such highly fluorinated compounds have enjoyed widespread industrial use for many years due to their chemical durability, excellent surfactant properties, and key role as precursors to fluoropolymers including polytetrafluoroethylene.

[0005] Unfortunately, these same properties make PFAS resistant to degradation in the environment, leading to bioaccumulation over time when ingested. Several recent studies have linked PFAS to a variety of adverse health effects, most notably increased cholesterol levels, but also kidney cancer, testicular cancer, thyroid disease, and pregnancy-induced hypertension.

[0006] To date, various techniques have been employed to remove PFAS from the environment and drinking water, but none are completely satisfactory. For example, some prior art has attempted to remove PFAS by contacting fluids containing PFAS with various adsorbents. However, the prior art fails to explain which chemical and microstructural properties of the adsorbent will or will not cause effective uptake of PFAS. Therefore, there is a need not only for more effective adsorbents themselves to better remove PFAS from the environment and drinking water, but also for those materials that are designed to have the desired chemical and microstructural properties. Summary of the invention

[0007] The present disclosure provides an adsorbent for removing one or more perfluoroalkyl and polyfluoroalkyl substances from a fluid. In one aspect, the present disclosure provides an adsorbent for removing one or more perfluoroalkyl and polyfluoroalkyl substances from a fluid, the adsorbent exhibiting a volumetric iodine number of about 450 mg / cm 3 To about 550mg / cm 3 , and the volume of molasses shown is about 100 cm -3 To about 400cm -3 .

[0008] In one embodiment, the adsorbent includes one or more of: carbonaceous carbon, activated carbon, reactivated carbon, and carbon black.

[0009] In another embodiment, the adsorbent includes one or both of activated carbon and reactivated carbon. In any embodiment, the activated carbon or the reactivated carbon can be formed from a precursor carbonaceous material, and the precursor carbonaceous material is selected from one or more of the following: bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, fruit pits, coconut shells, babassu nuts, macadamia nuts, dende nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum asphalt, bagasse, rice husks, corn husks, wheat husks and husks, graphene, carbon nanotubes and polymer fibers.

[0010] In another embodiment, the activated carbon or the reactivated carbon is formed from one or both of bituminous coal and sub-bituminous coal.

[0011] In another embodiment, the activated carbon or the reactivated carbon is reagglomerated.

[0012] In another embodiment, the adsorbent has a volume iodine number of about 450 mg / cm 3 To about 600mg / cm 3 , and the volume of molasses is about 100cm -3 To about 400cm -3 .

[0013] In another embodiment, a bed containing the adsorbent can remove PFOA from at least about 20,000 bed volumes of water containing PFOA at a concentration of about 61 ng / L or less, thereby producing a filtered water stream, and the concentration of PFOA detected in the filtered water stream is then about 15 ng / L.

[0014] In another aspect, the present disclosure provides a method for removing one or more perfluoroalkyl substances from a fluid, the method comprising: providing an adsorbent having a volume iodine number of at least about 450 mg / cm3 and a volume of molasses of at least about 100 cm -3 ; and contacting the fluid with the adsorbent.

[0015] In one embodiment, the adsorbent includes one or more of: carbonaceous carbon, activated carbon, reactivated carbon, and carbon black.

[0016] In another embodiment, the adsorbent includes one or both of activated carbon or reactivated carbon.

[0017] In another embodiment, the activated carbon or the reactivated carbon is formed from a precursor carbonaceous material, and the precursor carbonaceous material is selected from one or more of the following: bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, fruit pits, coconut shells, babassu nuts, macadamia nuts, palm nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum asphalt, bagasse, rice husks, corn husks, wheat husks and chaff, graphene, carbon nanotubes and polymer fibers.

[0018] In another embodiment, the activated carbon or the reactivated carbon is formed from one or more of bituminous coal and sub-bituminous coal.

[0019] In another embodiment, the activated carbon or the reactivated carbon is reagglomerated.

[0020] In another embodiment, the adsorbent has a volume iodine number of about 450 mg / cm 3 To about 600mg / cm 3 , and the volume of molasses is about 100cm -3 To about 400cm -3 .

[0021] In another embodiment, the adsorbent has a volume iodine number of about 500 mg / cm 3 To about 550mg / cm 3 , and the volume of molasses is about 110cm -3 About 350cm -3 .

[0022] In another embodiment, a bed containing the adsorbent can remove PFOA from at least about 20,000 bed volumes of water containing PFOA at a concentration of about 61 ng / L or less, thereby producing a filtered water stream, and the concentration of PFOA detected in the filtered water stream is then about 15 ng / L.

[0023] In another aspect, the present disclosure provides an adsorbent composition comprising one or more adsorbents and optionally a second adsorbent, wherein the one or more adsorbents have a volume iodine number of at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3 .

[0024] In one embodiment, the sorbent composition includes one or more inert materials, fillers, binders, or other compositions that do not have any appreciable sorbent capacity.

[0025] In another embodiment, the adsorbent has a volume iodine number of about 450 mg / cm 3 To about 600mg / cm 3 , and the volume of molasses is about 100cm -3 To about 400cm -3 .

[0026] In another embodiment, the adsorbent has a volume iodine number of about 500 mg / cm 3 To about 550mg / cm 3 , and the volume of molasses is about 110cm -3 About 350cm -3 .

[0027] In another example, a bed containing the adsorbent composition can remove PFOA from at least about 20,000 bed volumes of water containing PFOA at a concentration of about 61 ng / L or less, thereby producing a filtered water stream, and the concentration of PFOA detected in the filtered water stream is then about 15 ng / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The aspects, features, benefits and advantages of the embodiments described herein will be apparent with respect to the following description, appended claims and accompanying drawings, in which:

[0029] Figure 1 An example of a decolorization curve for a sample of an adsorbent as disclosed herein is provided.

[0030] Figure 2 Depicted are UV-Vis transmittance spectra collected from a sample of the filtrate of a molasses solution after treatment with activated carbon.

[0031] Figure 3 A plot of perfluorooctanoic acid (PFOA) concentration normalized to untreated water measured in water at the outlet port of an adsorbent bed comprising adsorbent of varying molasses numbers versus the number of bed volumes of water passing through the bed is provided.

[0032] Figure 4AScatter plots of Volume Molasses Number and Volume Iodine Number for various adsorbents as described herein versus bed volume corresponding to the concentration of PFOA in water reaching 25% of the PFOA concentration in untreated water at the outlet port of the bed are provided.

[0033] Figure 4B A plot of the bed volume corresponding to the concentration of PFOA in the water reaching 25% of the PFOA concentration in the untreated water at the outlet port of the bed as a function of the volume molasses number of adsorbent in the bed is provided. DETAILED DESCRIPTION

[0034] The present disclosure is not limited to the specific systems, devices and methods described, as the specific systems, devices and methods may vary. The terminology used in the specification is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope.

[0035] As used in this document, the singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nothing in this disclosure should be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term "comprising" means "including, but not limited to".

[0036] As used herein, the term "about" means ±10% of the numerical value of the value it modifies. Thus, about 50% means within the range of 45%-55%. When describing temperature, the term "about" means ±5 degrees of the specified temperature.

[0037] As used herein, the term "sorbent composition" means a material or mixture of materials that includes an sorbent. The sorbent composition may be formed entirely of the sorbent medium, or the sorbent may alternatively include one or more inert materials, fillers, binders, or other compositions that do not have any appreciable sorbent capacity.

[0038] As used herein, the term "adsorbent material" means all known materials from any source that are capable of adsorbing or absorbing liquids and / or gases. For example, the adsorbent medium may comprise, as non-limiting examples, one or more of carbonaceous char, activated carbon, reactivated carbon, carbon nanotubes, graphene, natural and synthetic zeolites, silica, silica gel, alumina, polystyrene sulfonate, aluminum oxide, zirconium oxide, and diatomaceous earth.

[0039] As used herein, the term "per- and polyfluoroalkyl substances (PFAS)" means any per- or polyfluoroalkyl substance, a mixture of such substances, or a derivative of one or more such substances. Examples of per- and polyfluoroalkyl substances include perfluoroalkyl sulfonates, perfluoroalkane sulfonic acid (PFSA), N-butyl perfluoroalkane sulfonamide (BuFASA), N-butyl perfluoroalkane sulfonamidoethanol (BuFASE), N-butyl perfluoroalkane sulfonamidoacetic acid (BuFASAA), N-ethyl perfluoroalkane sulfonamide (EtFASA), N-ethyl perfluoroalkane sulfonamidoethanol (EtFASE), N-ethyl perfluoroalkane sulfonamidoacetic acid (EtFASAA), perfluoroalkane sulfonamide (FASA), perfluoroalkane sulfonamidoethanol (FASE). , perfluoroalkanesulfonamidoacetic acid (FASAA), N-methyl perfluoroalkanesulfonamide (MeFASA), N-ethyl perfluoroalkanesulfonamidoacetic acid (MeFASAA), N-methyl perfluoroalkanesulfonamidoethanol (MeFASE), perfluoroalkanesulfonyl fluoride (PASF), fluoroprotein (FP), fluorotelomer carboxylic acid (FTCA), fluorotelomer alcohol (FTOH), fluorotelomer sulfonate (FTS), fluorotelomer sulfonic acid (FTSA), perfluoroalkyl acid (PFAA), perfluoroalkylsulfonamidoethanol (PFOSE), and any derivatives thereof.These include, for example and without limitation, ammonium perfluorooctanoate (APFO), 4,8-dioxa-3H-perfluorononanoate, N-methyl perfluorooctane sulfonamide (MeFOSA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate, perfluorooctane sulfonic acid (PFOS), 2,3,3,3,-tetrafluoro-2-(heptafluoropropoxy)propionate, ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propionate, 1,2,2,2-tetrafluoroethyl ether, 4:2-fluorotelomer sulfonic acid (4:2FtS), 6:2-fluorotelomer sulfonic acid (6:2FtS), 8: 2-Fluorotelomer sulfonic acid (8:2FtS), perfluorobutyric acid (PFBA), perfluorobutane sulfonate, perfluorobutane sulfonic acid (PFBS), perfluorohexane sulfonate, perfluorohexane sulfonic acid (PFHxS), perfluorohexanoate, perfluorohexanoic acid (PFHxA), 4,8-dioxa-3H-perfluorononanoate, ammonium perfluorooctanoate (APFO), N-ethyl perfluorooctane sulfonamide (EtFOSA), N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE), perfluorooctane sulfonamide (PFOSA), perfluorooctane sulfonamidoacetic acid (FOSAA), perfluorooctane sulfonamide (PFOSA), Fluorooctanesulfonamidoethanol (FOSE), perfluorobutyrate, perfluorobutyric acid, perfluorobutyrate, perfluorobutyric acid, perfluoroalkyl carboxylates, perfluoroalkyl carboxylic acids (PFCA), perfluorodecanoate, perfluorodecanoic acid (PFDA), perfluorododecanoate, perfluorododecanoic acid (PFDoA), perfluorododecane sulfonate (PFDoS), perfluorododecane sulfonic acid (PFDoSA), perfluorodecane sulfonate, perfluorodecane sulfonic acid (PFDS), perfluoroheptanoate, perfluoroheptanoic acid (PFHpA), perfluoroheptane sulfonate, perfluoroheptane sulfonic acid (PFHpS), perfluorononanoate , perfluorononanoic acid (PFNA), perfluorononane sulfonate, perfluorononane sulfonic acid (PFNS), perfluorooctanoate, perfluorophosphonic acid (PFPA), perfluorovalerate, perfluoropentanoic acid (PFPeA), perfluoropentane sulfonate, perfluoropentane sulfonic acid (PFPeS), perfluorophosphinic acid (PFPiA), perfluorotetradecanoic acid (PFTeDA), perfluorotridecanoic acid (PFTrDA), perfluoroundecanoate, perfluoroundecanoic acid (PFUnA), perfluoro-n-decane sulfonate (PFUnS), perfluoro-n-decane sulfonic acid (PFUnSA) and polytetrafluoroethylene (PTFE).

[0040] As used herein, "iodine number" or "IV" refers to either the weight iodine number or the volume iodine number. The iodine number is a measure of the equilibrium mass of iodine adsorbed on the surface of a normalized amount of an adsorbent. The iodine number is a measure of the surface area and porosity of an adsorbent.

[0041] As used herein, "weight iodine number" or "IV g "Iodine Number by Weight" refers to the property of an adsorbent formed from a carbonaceous material as determined by industry standard test ASTM D4607-14. Weight Iodine Number is reported in units of mass of iodine adsorbed per mass of adsorbent.

[0042] As used herein, the "volume iodine number" or "IV v ” means the product of the weight iodine number and the apparent density of the adsorbent. The apparent density of the adsorbent is obtained by the industry standard test ASTM D2854-09(2019). Weight iodine number has the meaning stated in the preceding paragraph. Volumetric iodine number is reported in units of mass of iodine adsorbed per volume of adsorbent.

[0043] As used herein, "molasses number" or "MN" refers to the weight molasses number or volume molasses number. The molasses number is a measure of the decolorization capacity of an adsorbent and is an indicator of the macroporous and transport pore structure of the adsorbent.

[0044] As used herein, "molasses number" or "MN g "" means the determination of the decolorization capacity of the adsorbent according to the Calcareous Carbon Method No. TM-3 entitled "Determination of the Molasses Number of Activated Carbon". The complete test procedure is fully described herein. The weight molasses number is reported as a unitless amount measured per mass of adsorbent.

[0045] As used herein, the "volume molasses number" or "MN v ” means the product of the weight molasses number and the apparent density of the adsorbent. The weight molasses number has the meaning set forth in the preceding paragraph. The apparent density of the adsorbent is obtained by the industry standard test ASTM D2854-09(2019). The volume molasses number is reported as a unitless amount measured per volume of adsorbent.

[0046] Adsorbents and adsorbent compositions

[0047] The present disclosure provides an adsorbent composition comprising at least one adsorbent effective in removing one or more perfluoroalkyl substances as described above from a fluid. The at least one adsorbent exhibits a volumetric iodine number of at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ), and exhibiting a volume molasses number of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3 ).

[0048] Advantageously, the volume iodine number is at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3The adsorbent may exhibit good ability to adsorb one or more perfluoroalkyl substances. In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 460 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 470 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 480 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 490 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 500 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 510 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 520 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 530 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 540 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 550 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 560 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 570 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In one embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 580 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In any embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 590 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In any embodiment, the one or more adsorbents exhibit a volume iodine number of at least about 600 mg / cm 3 , and exhibits a volume molasses number of at least about 100 cm -3 In any embodiment, the one or more adsorbents exhibit a volume iodine number of about 450 mg / cm 3 To about 500mg / cm 3 , about 470mg / cm 3 To about 550mg / cm 3 , about 500mg / cm 3 To about 550mg / cm 3 , about 520mg / cm 3 To about 550mg / cm 3 or about 490mg / cm 3 To about 520mg / cm 3 The aforementioned values ​​and ranges may be used alone or in combination, and any range may be formed by selecting two or more of the aforementioned end values.

[0049] In any embodiment, including those overlapping with the embodiment in the preceding paragraph, the one or more adsorbents exhibit a volume molasses number of about 100 cm -3 、Approx. 110cm -3 、Approx. 120cm -3 、Approx. 130cm -3 、Approx. 140cm -3 、Approx. 150cm -3 、Approx. 160cm -3 、Approx. 170cm -3 、Approx. 180cm -3 、Approx. 190cm -3 , about 200cm -3 、About 210cm -3 、About 220cm -3 、About 230cm -3、Approx. 240cm -3 、About 250cm -3 、About 260cm -3 、About 270cm -3 、About 280cm -3 、About 290cm -3 、About 300cm -3 、About 310cm -3 、About 320cm -3 、About 330cm -3 、About 340cm -3 、About 350cm -3 、About 360cm -3 、About 370cm -3 、About 380cm -3 、About 390cm -3 、Approx. 400cm -3 Or any range by selecting two or more of the above values ​​as end values.

[0050] The apparent density of the adsorbents as disclosed herein is not limited and in any embodiment may be less than about 1.00 g / cm 3 , less than about 0.95g / cm 3 , less than about 0.90g / cm 3 , less than about 0.85g / cm 3 , less than about 0.80g / cm 3 , less than about 0.75g / cm 3 , less than about 0.70g / cm 3 , less than about 0.65g / cm 3 , less than about 0.60g / cm 3 , less than about 0.55g / cm 3 , less than about 0.50g / cm 3 , less than about 0.45g / cm 3 , less than about 0.40g / cm 3 or less than about 0.35 g / cm 3 In any embodiment, the apparent density of the adsorbent may be about 1.00 g / cm 3 , about 0.95g / cm 3 , about 0.90g / cm 3 , about 0.85g / cm 3 , about 0.80g / cm 3 , about 0.75g / cm 3 , about 0.70g / cm 3 , about 0.65g / cm 3 , about 0.60g / cm 3, about 0.55g / cm 3 , about 0.50g / cm 3 , about 0.45g / cm 3 , about 0.40g / cm 3 , about 0.35g / cm 3 , about 0.30g / cm 3 Or any range by selecting two or more of the above values ​​as end values. In any embodiment, the apparent density of the adsorbent can be about 0.30 g / cm 3 To about 1.00g / cm 3 , about 0.30g / cm 3 To about 0.95g / cm 3 , about 0.30g / cm 3 To about 0.90g / cm 3 , about 0.30g / cm 3 To about 0.85g / cm 3 , about 0.30g / cm 3 To about 0.80g / cm 3 , about 0.30g / cm 3 To about 0.75g / cm 3 , about 0.30g / cm 3 To about 0.70g / cm 3 , about 0.30g / cm 3 To about 0.65g / cm 3 , about 0.30g / cm 3 To about 0.60g / cm 3 , about 0.30g / cm 3 To about 0.55g / cm 3 , about 0.30g / cm 3 To about 0.50g / cm 3 , about 0.30g / cm 3 To about 0.45g / cm 3 , about 0.30g / cm 3 To about 0.40g / cm 3 or about 0.30g / cm 3 To about 0.35g / cm 3 .

[0051] The adsorbent composition may include one or more adsorbents, each adsorbent including or derived from an adsorbent medium selected from, but not limited to, one or more of the following: carbonaceous carbon, activated carbon, carbon nanotubes, graphene, reactivated carbon, carbon black, natural and synthetic zeolites, silica, silica gel, alumina, alumina clay, zirconia, diatomaceous earth, and metal oxides. In any embodiment, the adsorbent composition including one or more adsorbents may include or be derived from a single type of adsorbent medium, or may be combined with adsorbents including or derived from one or more additional types of adsorbent media or non-adsorbent media. In embodiments where the adsorbent composition includes two or more types of adsorbents, the two or more adsorbents may be mixed together and may include or be derived from the same or different precursor materials selected from the above materials.

[0052] In any embodiment, the one or more adsorbents may include one or both of activated carbon and reactivated carbon. In such embodiments, the activated carbon and / or reactivated carbon may be prepared from any precursor carbonaceous material known in the art, including but not limited to: bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, coconut including coconut shells, sawdust, peat, nut shells, fruit pits, babassu nuts, macadamia nuts, palm nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum asphalt, bagasse, rice husks, corn husks, wheat husks and husks, graphene, carbon nanotubes, polymer fibers, any other carbonaceous material, or any combination thereof. In any embodiment, the reactivated carbon may be derived from any source of activated carbon that has been depleted or substantially depleted due to use.

[0053] Activated carbon and reactivated carbon suitable for use with the adsorbents and adsorbent compositions disclosed herein can be of any grade or type, selected based on performance requirements, cost, and / or other considerations. The activated carbon or reactivated carbon can be used in one or more of a powder form, a granular form, or a pellet form, the powder form being referred to as "powdered activated carbon" or "PAC", the granular form being referred to as "granular activated carbon" or "GAC", and the pellet form being referred to as pelletized activated carbon. In any embodiment, the adsorbent may include activated carbon or reactivated carbon in one of the forms of PAC, GAC, or pelletized, or may include a mixture of two or more forms. As used herein, powdered activated carbon (PAC) is defined as particles that pass through an 80 mesh sieve (pores of about 0.180 mm). As used herein, granular activated carbon (GAC) is defined as activated carbon particles sized to be retained on a 50 mesh sieve (pores of about 0.300 mm). While these particle size ranges are mentioned for activated carbon adsorbents, it is also contemplated that any of the disclosed adsorbents can pass through the above 50 mesh and 80 mesh sieve size measurements.

[0054] In any embodiment, the adsorbent composition may include a bulk iodine number of at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3 The adsorbent composition may include an adsorbent such as an additional adsorbent for removing one or more per- and polyfluoroalkyl substances, an adsorbent for removing non-PFAS compounds, or one or more additional components other than an adsorbent. For example, in any embodiment, the adsorbent composition may include at least two different adsorbent types, each adsorbent type being effective to absorb or adsorb one or more per- and polyfluoroalkyl substances. In any embodiment, the adsorbent composition described herein may further include at least one compound that is not an adsorbent and may not substantially absorb or adsorb per- and polyfluoroalkyl substances or any other compound.

[0055] For example, in any embodiment, a sorbent composition can be formed that includes a volume iodine number of at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3 The composition can be molded, extruded or otherwise formed into one or more shapes, such as pellets. The type of binder is not particularly limited and can include any organic or inorganic binder known in the art. Taking inorganic binders as an example, metals, ceramics, clays, glasses or a combination of one or more of the above are commonly used. Taking organic binders as an example, petroleum resins and / or asphalts, natural resins and / or asphalts, polymers or a combination of one or more of the above are commonly used.

[0056] In any embodiment, the iodine number is at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3 The adsorbent composition of one or more adsorbents may be provided in a container. The container may hold a volume of iodine number of at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3An adsorbent composition comprising one or more adsorbents is configured and sized to receive a fluid (i.e., a liquid or gas) and convey the fluid through or through a container, thereby contacting the fluid with the adsorbent composition and one or more adsorbents thereof. The type of container is not particularly limited. For example, in any embodiment, the container can be a permanent container that is installed in an apparatus or processing facility and is connected by a pipe or other fluid conduit so that the liquid or gas flows through the container. The used adsorbent can be emptied from the container from time to time and replaced by one or both of the original adsorbent or the reactivated adsorbent to ensure that the adsorbent remains effective in removing perfluoroalkyl substances or chemically similar or chemically related compounds from the liquid or gas flowing through the container. The physical form of the adsorbent composition including one or more adsorbents provided in the container is not limited and can be provided loose (alone) or formed into a cartridge together with other structural materials to hold it in place.

[0057] In another example, and in any embodiment, the container itself can be designed to be quickly replaced and with minimal changes to external components, such as pumps and conduits that deliver liquids or gases to the container. In such embodiments, the container may be referred to as a "cartridge", and it may be connected and or disconnected from surrounding components. In any embodiment, the cartridge may be disposable, such as in consumer drinking water applications. Alternatively, in another example and in any embodiment, the cartridge may be intended to be refurbished, wherein the cartridge containing the spent adsorbent is returned for cleaning or reactivation of the adsorbent, refilled with fresh original or reactivated adsorbent, and returned to use after the refurbishment operation is completed.

[0058] Preparation method

[0059] The adsorbent composition comprises an aqueous solution effective in removing per- and polyfluoroalkyl substances and exhibiting a volumetric iodine number of at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ), and exhibiting a volume molasses number of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3 ) of one or more adsorbents.

[0060] The volume iodine number is at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3The one or more adsorbents may be formed from one or more precursor materials selected from, but not limited to, carbonaceous carbon, activated carbon, carbon nanotubes, graphene, reactivated carbon, carbon black, natural and synthetic zeolites, silica, silica gel, alumina, alumina clay, zirconia, diatomaceous earth, and metal oxides. When the adsorbent comprises activated carbon or reactivated carbon, the activated carbon and reactivated carbon may be of any grade or type, such as PAC, GAC, pelletized activated carbon, any reactivated form thereof, or any combination thereof.

[0061] Granular activated carbon or reactivated carbon can be formed by crushing the precursor carbonaceous material into a powder of a desired size. The powder may optionally be mixed with a binder. The crushed material may then be formed into a mass, optionally together with a binder, which may then be subsequently ground into particles of a desired size. The resulting granular material may then be carbonized to change its properties, such as, but not limited to, removing volatile compounds and activating the precursor carbonaceous material.

[0062] Agglomerated activated carbon can be formed by pulverizing a precursor carbonaceous material, combining the pulverized material with a binder, and extruding the mixture into pellets. The pellets can then be carbonized to change their properties, such as, but not limited to, removing volatile compounds and activating the precursor carbonaceous material.

[0063] Adsorbents made from activated carbon and / or reactivated carbon may be formed by any process known in the art, provided that the final adsorbent product exhibits a volumetric iodine number of at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ), and a volume of molasses of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3 ).

[0064] For example, activated carbon can be formed by oxidizing and devolatilizing raw carbonaceous materials with steam and / or carbon dioxide, and the activated carbon can be gasified to form a desired pore structure in the activated carbon, thereby providing desired material properties (e.g., weight iodine number, weight molasses number). In any embodiment, the initial oxidation and devolatilization process can include chemical treatment with dehydration chemicals such as phosphoric acid, sulfuric acid, sodium hydroxide, potassium hydroxide, and combinations of these.

[0065] In another example, suitable activated carbon can be formed by a direct activation process. Such activated carbon adsorbents are sometimes referred to as direct activated carbon. In a direct activation process, a precursor carbonaceous material, typically coal, is crushed and sized. The crushed and sized precursor carbonaceous material is then carbonized and thermally activated.

[0066] In any embodiment, suitable adsorbents may include reactivated adsorbents that have previously had their adsorbent capacity depleted or substantially depleted and have been reactivated to restore at least some of the original adsorbent capacity. Any of the adsorbents listed above may be reactivated after depletion, and the reactivation may be performed by heat, pressure, chemical exposure, or any combination thereof. In any embodiment, the reactivated adsorbent may include reactivated carbon. Reactivated carbon may be manufactured by heating used depleted activated carbon using steam as a selective oxidant in a low oxygen atmosphere. During reactivation, absorbed and adsorbed organic compounds may volatilize or pyrolyze from the activated carbon to form carbonaceous char. Heating may occur at a temperature above about 500°C (e.g., about 500°C to about 1100°C), more specifically above about 700°C (e.g., about 700°C to about 1100°C), and the resulting reactivated carbon may be reused for various purposes thereafter, including water treatment.

[0067] Although any process may be used to produce a volumetric iodine number of at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ) and a volume of molasses of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3 ) adsorbent, but the following observations may provide useful guidance to those skilled in the art because the volume iodine number and volume molasses number of a particular adsorbent are affected by many factors, including the selection of one or more of the precursor carbonaceous materials and the processing steps performed on the precursor carbonaceous materials. For example, in general, continued steam activation of the precursor carbonaceous material typically increases the weight iodine number and the weight molasses number, but simultaneously reduces the apparent density of the carbonaceous material. For many precursor carbonaceous materials, there is a maximum weight molasses number that can be achieved before further activation causes the weight molasses number to decrease. Therefore, simply increasing the weight iodine number and the weight molasses number may not increase the volume iodine number and the volume molasses number beyond a certain value. Taking all of the above into consideration, the present disclosure describes adsorbents that maximize both the volume iodine number and the volume molasses number to achieve excellent performance.

[0068] Although the adsorbents of the present disclosure are primarily disclosed as removing perfluoro and polyfluoroalkyl substances or chemically similar or chemically related compounds, the use of the adsorbents is not limited thereto. In still other embodiments, the adsorbents are suitable for removing any compounds and / or byproducts that cause taste and odor problems in water. Such compounds are referred to as "taste and odor compounds" throughout the application. Examples of such taste and odor compounds include one or more of the following: trans-1,10-dimethyl-trans-9-decanol ("Geosmin"), 2-methylisoborneol (MIB), isopropylmethoxypyrazine (IPMP), isobutylmethoxypyrazine (IBMP), methyl tert-butyl ether (MTBE), 2,4-heptane, decane, octanal, chlorine, chloramines, chlorophenol, iodoform, hydrocarbons, and volatile organic oxides (VOCs).

[0069] As described herein, the surface and pore morphology of the adsorbent is described by a combination of a volume iodine number and a volume molasses number. While not wishing to be bound by theory, the combination of the volume iodine number and the volume molasses number together describes both the overall adsorption capacity of the adsorbent and the types of molecules that the adsorbent is effective at adsorbing. After intensive experimentation, Applicants determined that only a volume iodine number of at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ) and a volume of molasses of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3 ) cannot meet the requirements of good adsorbents / adsorbent capacity for a wide range of PFAS. Along the same lines, a material with a very high measurement of one of the gravimetric iodine number and gravimetric molasses number cannot compensate for a lower measurement of the other. Applicants have also determined that it is volumetric measurements rather than gravimetric measurements that best describe the performance of an adsorbent with respect to PFAS, and therefore, apparent density is equally important in providing effective adsorbent compositions and adsorbents for removing PFAS from fluids.

[0070] How to use

[0071] Advantageously, the volume iodine number formed by the process described herein is at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ) and a volume of molasses of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3) have excellent performance in removing one or more perfluorinated and fluoroalkyl species from fluids such as water (e.g., drinking water).

[0072] Thus, provided herein is a method for removing one or more perfluoroalkyl substances from a fluid, the method comprising contacting an adsorbent composition comprising one or more adsorbents disclosed herein with a fluid containing one or more perfluoroalkyl substances compounds. As described above, at least one of the one or more adsorbents exhibits a volumetric iodine number of at least about 450 mg / cm 3 (e.g. about 450 mg / cm 3 To about 600mg / cm 3 ), and exhibiting a volume molasses number of at least about 100 cm -3 (For example, about 100cm -3 To about 400cm -3 ).

[0073] The contact method is not particularly limited. For example, in any embodiment, the stream comprising a fluid can pass through or pass through a bed comprising an adsorbent composition, and the adsorbent composition comprises one or more adsorbents. In another example, the adsorbent composition comprising one or more adsorbents can be injected into the fluid or otherwise combined with the fluid. Optionally, after absorbing one or more perfluoro and polyfluoroalkyl substances of a desired amount from the fluid, the adsorbent composition comprising one or more adsorbents can be collected from the fluid, for example, by filtering the fluid to separate the adsorbent composition. The composition of the fluid is not limited, and in any embodiment, one or more of liquid water, water vapor, air and soil can be included.

[0074] Examples

[0075] Before describing the examples, a complete description of the test methods must be given.

[0076] Determination of iodine number (IV)

[0077] The gravimetric iodine number of the activated carbon sample is measured according to ASTM D4607- 14. The gravimetric iodine number is reported in milligrams of iodine adsorbed per gram of activated carbon sample.

[0078] To calculate the volumetric iodine number, the apparent density (ρ) of the activated carbon sample was measured according to the industry standard test ASTM D2854-09 (2019) b ). After obtaining the weight iodine number and the apparent density, the volume iodine number is determined by multiplying the weight iodine number by the apparent density. Therefore, the volume iodine number is reported in mg / cm3.

[0079] Determination of weight molasses number (MN g )

[0080] To determine the gravimetric molasses number, Calgon Carbon Corporation Test Method Number TM-3 (“TM-3”) was utilized. TM-3 is intended to determine the decolorization capacity of activated carbon. The decolorization capacity of activated carbon describes the pore structure and material transport of the activated carbon. The gravimetric molasses number is determined according to TM-3. The volumetric molasses number (MN) is calculated by multiplying the TM-3 molasses number by the apparent density obtained by ASTM D2854-09(2019). v ). The weight molasses number was determined by TM-3 as follows:

[0081] Limitations: The concentration of the molasses solution used for the test depends on the standard carbon. As used herein, "standard carbon" is an activated carbon adsorbent that is a reference material for the characteristics of the weight molasses number. As understood by a skilled practitioner in the art, "200 standard carbon" can be expected to produce a weight molasses number of 200, "250 standard carbon" can be expected to have a weight molasses number of 250, and so on. 200 standard carbon must be used for activated carbon products predicted to have a weight molasses number of less than 230. 250 standard carbon must be used for activated carbon products predicted to have a weight molasses number of less than 350. 400 standard carbon must be used for activated carbon products predicted to have a weight molasses number of 350 or greater. Whenever the molasses specification range of the product includes the molasses standard carbon range, the higher molasses standard carbon should be used. In these cases, it is appropriate to include the molasses standard carbon to be utilized on the product specification as an instruction for manufacturing. The molasses solution may not be diluted. A fixed optical path length of 2.5 mm must be used.

[0082] As will be appreciated by those skilled in the art, standard carbon is not limited, provided that the standard carbon is a reference material suitable for molasses number. An example of 400 standard carbon is "RB", which is available from Calgon Carbon Company of Moon Township, PA. RB is a powdered steam activated carbon made from bituminous coal with a minimum weight iodine number of 1070 mg / g, a weight molasses number of 400, a maximum ash content of 23 wt.%, a maximum moisture content of 2 wt.%, and 60-75 wt.% of particles screened at 325 mesh or less than 44 μm in size. A second example of 320 standard carbon is "RC", which is available from Calgon Carbon Company of Moon Township, PA. RC is a powdered steam activated carbon made from bituminous coal with a minimum weight iodine number of 1020 mg / g, a weight molasses number of 320, a maximum ash content of 23 wt.%, a maximum moisture content of 2 wt.%, and 60-75 wt.% of particles screened at 325 mesh or less than 44 μm in size. A third example of 230 standard carbon is "BL", available from Calgon Carbon Company, Moon Township, Pa. BL is a powdered steam activated carbon made from bituminous coal having a minimum weight iodine number of 1000 mg / g, a weight molasses number of 230, a maximum ash content of 10 wt.%, a maximum moisture content of 2 wt.%, and having 60-75 wt.% of the particles screened at 325 mesh or less than 44 μm in size.

[0083] Method principle: A blackstrap molasses solution is treated with a standard carbon with a known molasses number ("molasses standard carbon"), filtered, and the filtrate is analyzed by UV-vis spectrophotometry to generate a relationship between the molasses number and the absorbance. Then, the blackstrap molasses solution is treated with a carbon sample of unknown decolorization ability / unknown molasses number (e.g., an adsorbent provided herein), filtered, and the filtrate is analyzed in the same manner. The higher the ability of the adsorbent to decolorize the molasses composition (i.e., decolorize), the brighter the filtrate will be, and conversely, the lower the absorbance. Therefore, a higher molasses number corresponds to a higher decolorization ability, such as Figure 1 The absorbance of each filtrate was measured on a standard spectrophotometer with a wavelength of 472 nm and an optical path length of 2.5 mm ( Figure 2 The transmittance spectra of representative filtrates are depicted). The molasses number for each sample was calculated from the ratio of the absorbance values ​​of the sample and the carbon standard:

[0084] Molasses number = (A × B) / C

[0085] wherein A is the molasses number of a standard carbon with known molasses number; B is the average absorbance of three measurements of a standard carbon with known molasses number; and C is the absorbance of the filtrate of the adsorbent being analyzed (ie, with unknown molasses number).

[0086] SAFETY PRECAUTIONS: Careful handling and good laboratory technique should always be used when working with laboratory equipment. Personnel performing this testing should be aware of the potential safety hazards associated with the equipment used in this procedure.

[0087] The instruments used in TM-3 are described in Table 1 below:

[0088] Table 1

[0089]

[0090] The reagents used in TM-3 are described in Table 2 below:

[0091] Table 2

[0092]

[0093] A blackstrap molasses solution ("standardized molasses solution") for determining the molasses number was prepared according to the following procedure:

[0094] 1. Weigh about 50 grams of blackstrap molasses into a clean, dry beaker and set aside until the water is heated to 95°C.

[0095] 2. Using a graduated cylinder, add 1000 mL of ASTM Type 2 water to a stainless steel beaker.

[0096] 3. Cover the beaker with aluminum foil or a large glass lid, place on a hot plate, and heat to 95°C.

[0097] 4. When the water reaches 95°C, transfer the weighed molasses to the stainless steel beaker and stir to mix thoroughly. Remove the stainless steel beaker from the hot plate.

[0098] 5. Cool the solution to room temperature (about 25°C).

[0099] 6. Siphon the molasses solution from the stainless steel beaker into a suitable container. Place a piece of TYGON tubing in the beaker so the end of the tubing is one inch from the bottom of the beaker. Use a pipette bulb to start the siphon. Siphon the solution into a separate container (e.g., a large glass bottle).

[0100] 7. Discard the remaining beaker contents. Store the molasses solution in the refrigerator for up to 24 hours. Keep the molasses solution on ice while running the detection method.

[0101] 8. Weigh 0.46 ± 0.0002 g of 250 molasses standard carbon into a clean, dry 400 mL beaker.

[0102] 9. Pipette 50 mL of molasses solution into the beaker. Vortex the beaker while adding the molasses solution until the 250 molasses standard carbon is completely wetted.

[0103] 10. Place the beaker on a hot plate and place the thermocouple / thermometer in the beaker so that the tip rests on the bottom of the beaker. Heat the solution until the thermocouple / thermometer reaches 98°C and start a stopwatch. Remove the thermocouple or thermometer and boil the solution for 30 seconds.

[0104] 11. Use the previously prepared The sample was filtered through a Buchner funnel by vacuum using No. 3 filter paper. The filtrate was covered with about 20 mL of the solution and the filtrate was discarded. The remainder was filtered.

[0105] 12. Measure and record the absorbance of the filtrate at a wavelength of 472 nm using the instrument parameters specified above. The filtrate is considered standardized when the absorbance is between 0.630 and 0.650 ("Standardized 250 Filtrate").

[0106] 13. When the measured absorbance is greater than 0.650, the filtrate is considered too dark. In such cases, water can be added to the molasses solution. To determine the amount of water required, the volume of the remaining molasses solution is measured, multiplied by 0.640, and further multiplied by the absorbance recorded from step 12. This value is subtracted from the total volume of the molasses solution, where the result is the required volume of water added to the molasses solution. Water is added, and the solution is mixed thoroughly. Repeat steps 8-13 until the absorbance values ​​(at 472 nm) of three consecutive analyzed samples are between 0.630 and 0.650.

[0107] 14. When the measured absorbance is less than 0.630, the filtrate is considered too bright. In such cases, more molasses can be added to the molasses solution. To determine the amount of molasses to be added, the volume of the molasses solution is measured, multiplied by 0.640, and further multiplied by the absorbance recorded from step 12. This value is subtracted from the total volume of the molasses solution, divided by 10, and the result represents the amount (weight) of molasses that should be added to the molasses solution. Add the required amount of molasses to a small glass beaker. Add about 25 mL of molasses solution to the beaker to dissolve the molasses. Heat the beaker to 90°C on a hot plate and cool slightly thereafter. Add the contents to the molasses solution and mix thoroughly. Repeat steps 8-14 until three consecutive samples with absorbance values ​​(at 472 nm) between 0.630 and 0.650 are obtained.

[0108] 400 standard carbon standardization

[0109] 15. Weigh 0.46 ± 0.0002 g of 400 molasses standard carbon into a clean, dry 400 ml beaker.

[0110] 16. Pipette 50 mL of molasses solution into the beaker. Vortex the beaker while adding the molasses solution until the carbon is completely wetted.

[0111] 17. Place the beaker on a hot plate and place the thermocouple / thermometer in the beaker so that the tip rests on the bottom of the beaker. Heat the solution until the thermocouple / thermometer reaches 98°C and the stopwatch starts. Remove the thermocouple or thermometer and boil the solution for 30 seconds.

[0112] 18. Use the previously prepared The sample was filtered through a Buchner funnel by vacuum using No. 3 filter paper. The filtrate was covered with about 20 mL of solution and the filtrate was discarded. The remaining 30 mL portion was filtered and the filtrate was used for subsequent measurements.

[0113] 19. Measure and record the absorbance of the filtrate at a wavelength of 472 nm using a 2.5 mm fixed pathlength cell. The filtrate is considered standardized when the measured absorbance is between 0.390 and 0.410.

[0114] 20. When the measured absorbance is greater than 0.410, the filtrate is considered too dark. In such cases, water can be added to the molasses solution. To determine the amount of water required, the volume of the remaining molasses solution is measured, multiplied by 0.400, and further multiplied by the absorbance recorded from step 19. This value is subtracted from the total volume of the molasses solution, where the result is the required volume of water added to the molasses solution. Water is added, and the solution is mixed thoroughly. Steps 8-13 are repeated until the absorbance values ​​(at 472 nm) of three consecutive analyzed samples are measured to be between 0.390 and 0.410.

[0115] 21. When the absorbance is less than 0.390, the solution is considered too bright. In such cases, more molasses can be added to the molasses solution. To determine the amount of molasses to be added, the volume of the molasses solution is measured, multiplied by 0.640, and further multiplied by the absorbance recorded from step 19. This value is subtracted from the total volume of the molasses solution, divided by 10, and the result represents the amount (weight) of molasses that should be added to the molasses solution. Add the required amount of molasses to a small glass beaker. Add about 25 mL of molasses solution to the beaker to dissolve the molasses. Heat the beaker to 90°C on a hot plate and cool slightly thereafter. Add the contents to the molasses solution and mix thoroughly. Repeat steps 15-21 until three consecutive samples with absorbance values ​​(at 472 nm) between are obtained, thereby producing a standardized molasses solution for subsequent use.

[0116] Sample analysis

[0117] The samples were analyzed according to the following procedure:

[0118] 1. Provide a carbon sample of unknown molasses number and grind it until 95% or more of the molasses passes through a 325 mesh screen. If the sample is not from recent production, dry it at 150°C to constant weight before use. Prepare a standard carbon internal carbon standard in the same manner. Grind equal amounts to ensure that the fineness of the materials is comparable.

[0119] 2. Weigh a 0.46 ± 0.0002 gram portion of the dried pulverized carbon sample into a separate clean and dry 400 mL beaker.

[0120] 3. Prepare the filter setup for sample filtration. Place the No. 3 filter ring in the Buchner funnel. Connect the funnel to a 250 mL filter flask and start vacuum filtration. Add 50 mL of filter paper suspension, making sure to coat the entire surface of the filter paper ring. After all liquid has drained off, discard the filtrate collected in the filter flask.

[0121] 4. Pipette 50 mL of the standardized molasses solution into the beaker containing the carbon to be analyzed. Vortex the beaker while adding the standardized molasses solution until the carbon is completely wetted.

[0122] 5. Place the beaker on a hot plate and place the thermocouple or thermometer in the beaker so that the tip rests on the bottom of the beaker. Heat the solution until the thermocouple reads 98°C and the stopwatch starts. Remove the thermocouple or thermometer and allow the solution to boil for 30 seconds.

[0123] 6. Use the previously prepared The sample was filtered through a Buchner funnel by vacuum through No. 3 filter paper. The filter was covered with approximately 20 mL of sample and the filtrate was discarded. The remainder was filtered.

[0124] 7. Use 2.5mm fixed optical path KLETT TM The Summerson cell measures and records the absorbance of the filtrate at a wavelength of 472 nm. Deionized or distilled water is used as a reference.

[0125] 8. The molasses number is calculated as follows:

[0126] Molasses number = (A × B) / C

[0127] Where A is the molasses number of the standard carbon (250 or other); B is the average absorbance of three measurements for the 250 standard carbon or other standard carbon; and C is the absorbance of the filtrate of the activated carbon analyzed.

[0128] 9. Report the molasses number to the nearest increment of ten using conventional rounding techniques. (e.g. 226 = 230)

[0129] Example 1

[0130] For Example 1, a sample of 12 x 40 granular activated carbon is prepared for use in a fixed bed or a moving bed to purify and decolorize aqueous liquids and organic liquids. The sample is a reagglomerated activated carbon formed by bituminous coal. First, the bituminous coal is crushed into powder, and then a binder is added to the powder. Then the powder and the binder are reagglomerated into agglomerates. After agglomeration, the agglomerates are crushed and sized. The size setting only retains the particle size between 12 meshes (1.70 mm hole size) and 40 meshes (0.425 mm hole size). Note that, as described herein, the mesh size is by US mesh size. The average particle size of the sample batch is between 0.9 mm and 1.1 mm, and the amount of the granular activated carbon with a particle size greater than 12 meshes (1.70 mm) does not exceed 5.0 wt.%. The amount of the granular activated carbon with a particle size less than 40 meshes (0.425 mm) does not exceed 4 wt.%. The crushed and sized particles are carbonized, then thermally activated. After thermal activation, the moisture content of the granular activated carbon of Example 1 was less than 2 wt.% when measured by ASTM D2867, and the abrasion value was 75 when measured by AWWA B604, and the apparent density was 0.49 g / cm as measured by ASTM D2854-09. 3 .

[0131] Example 2

[0132] A sample of reagglomerated particulate activated carbon was prepared in the same manner as described in Example 1, except that the activation was performed so that the apparent density of the resulting product was 0.42 g / cm 3 .

[0133] Example 3

[0134] A sample of reagglomerated particulate activated carbon was prepared in the same manner as described in Example 1, except that the activation was performed so that the apparent density of the resulting product was 0.38 g / cm 3 .

[0135] Comparative Example 1 (C1)

[0136] Prepare a sample of granular activated carbon for Comparative Example 1. In Comparative Example 1, the sample is an activated carbon formed from coconut shells. First, coconut shells are treated by slow pyrolysis to form charcoal. Size setting is performed according to ASTM D2862-16 to retain only the particle size between 12 mesh (1.70mm pore size) and 40 mesh (0.425mm pore size). The amount of granular activated carbon with a particle size greater than 12 mesh (1.70mm) is not more than 5wt.%. The amount of granular activated carbon with a particle size less than 40 mesh (0.425mm) does not exceed 4wt.%. Next, the granules of size setting are activated. As measured by ASTM D3802, the hardness value of the granular activated carbon produced is at least 95. As measured by ASTM D2854, the apparent density of the granular activated carbon produced is 0.48g / cm 3 .

[0137] Comparative Example 2 (C2)

[0138] Prepare a sample of granular activated carbon for comparative example 2. In comparative example 2, the sample is a reagglomerated activated carbon formed by bituminous coal. First, the bituminous coal is crushed into powder, and then a binder is added to the powder. Then the powder and the binder are reagglomerated into agglomerates. After agglomeration, the agglomerates are crushed and sized. Size setting is performed according to ASTM D2862-16 to retain only the particle size between 12 meshes (1.70mm hole size) and 40 meshes (0.425mm hole size). The amount of particles larger than 12 meshes (1.70mm) does not exceed 5wt.%. The amount of particles smaller than 40 meshes (0.425mm) does not exceed 4wt.%. Next, the crushed and sized agglomerates are carbonized and then thermally activated. The hardness value measured by ASTM D3802 is at least 75. The apparent density measured by ASTM D2854 is 0.54g / cm 3 .

[0139] Comparative Example 3 (C3)

[0140] Samples prepared from granular activated carbon based on commercial sources of lignite were also tested. HYDRODARCO 4000 is a granular activated carbon based on lignite that is sized to retain only particle sizes between 12 mesh (1.70 mm pore size) and 40 mesh (0.425 mm pore size) according to ASTM D2862-16. The amount of granular activated carbon with a particle size greater than 12 mesh (1.70 mm) is no more than 5 wt.%. The amount of granular activated carbon with a particle size less than 40 mesh (0.425 mm) is no more than 4 wt.%.

[0141] Comparative Example 4 (C4)

[0142] Samples prepared from commercially sourced activated carbons were tested. The activated carbon of Comparative Example 4 was a granular activated carbon formed by direct activation of bituminous coal.

[0143] result

[0144] The effectiveness of Examples 1-3 and Comparative Examples 1-4 in removing specified perfluoroalkyl substances was tested. Six beds were prepared according to ASTM D6586, each consisting only of the activated carbon of each of Examples 1-3 and Comparative Examples 1-3. Tests were performed according to EPA Method 537 Version 1.1, which measures the adsorption of pollutants by granular activated carbon in aqueous systems by the Rapid Small Scale Column Test (RSSCT) prepared as above. The water supply was passed through the bed, and the concentration of perfluoroalkyl substances at the outlet was measured at specified intervals. In order to normalize the size of the bed, the results are reported in units of "bed volume", which is the volume of water passing through the activated carbon bed divided by the volume of the bed itself. During the test, it was noted that 25% of the concentration of perfluoroalkyl substances "penetrated" the activated carbon bed. For a specified adsorbent, a higher bed volume at 25% penetration means that the same amount of adsorbent adsorbs a larger amount of perfluoroalkyl substances and is therefore more effective.

[0145] In the results, PFOA is perfluorooctanoic acid (also known as IUPAC nomenclature pentafluorooctanoic acid or simply C8). Examples 1-3 and Comparative Examples 1-4 were tested for the amount of water that could pass through the bed of activated carbon before the pollutant PFOA at a concentration of at least 25% "penetrated" the activated carbon bed, that is, the amount detected in the filtered water. The results are shown in Table 3 below. Examples 1-3 and Comparative Examples 1-3 were also tested for the amount of water that could pass through the bed of activated carbon before the pollutant 4:2FtS at a concentration of at least 25% "penetrated" the activated carbon bed. 4:2FtS is a 4:2 fluorotelomer sulfonic acid and is a perfluoro and polyfluoroalkyl substance with a low molecular weight that makes it difficult to adsorb. Based on the testing of Examples 1-3 and Comparative Examples C1-C4, the following results were obtained:

[0146] Table 3

[0147]

[0148] *Extrapolated value

[0149] The results are still Figure 3 , 4A and 4B. Figure 3The normalized concentration of PFOA measured in the column effluent is plotted against the number of bed volumes of water that passed through the activated carbon adsorbent bed. In these experiments, a certain concentration of PFOA was present in the incoming water. The horizontal line corresponds to 25% of the initial concentration of PFOA measured at the outlet port of the activated carbon adsorbent bed. Therefore, Figure 3 The larger the portion of the plotted curve that exists below the horizontal line, the better the performance.

[0150] Figure 4A The bed volume number until 25% of PFOA penetrates the activated carbon adsorbent bed is depicted on the horizontal axis. As described above, a certain concentration of PFOA is present in the incoming water. Each vertical pair of data points represents a single experimental test. For example, the dashed vertical line represents a single material tested and exhibited 25% PFOA breakthrough at approximately 10,000 bed volumes. The volume molasses number of the material is approximately 160 cm -3 (represented by squares connected by vertical lines), and the volume iodine number is about 250 mg / cm 3 (Represented by diamonds connected by vertical lines.) Best fit lines for both volume iodine number and volume molasses number corresponding to each sample are provided.

[0151] Figure 4B The bed volume equivalent of 25% PFOA measured at the outlet port of the bed is plotted as a function of the volume molasses number of the sample. Each sample in the sample is Figure 4A The samples are the same as those shown in Figure 2. Two correlations were also found. First, an overall correlation was performed on all data points in the data set, which gave R 2 The value is 0.8968. This indicates a poor fit. However, the inventors have also found that if the volume iodine number is less than about 450 mg / cm 3 And the volume of molasses is less than about 100cm -3 The second correlation is performed on all data points of those data points, then R 2 The value improves to 0.9928, which indicates the best fit.

Claims

1. An adsorbent for removing one or more perfluoroalkyl and polyfluoroalkyl substances (PFAS) from a fluid, comprising: activated carbon, reactivated carbon, or a combination thereof, wherein the activated carbon, reactivated carbon, or a combination thereof is reagglomerated, The volume iodine number of the adsorbent is 450 mg / cm 3 Up to 600 mg / cm 3 , volume molasses number is 150 cm -3 Up to 400 cm -3 , and the apparent density is less than 0.45 cm -3 .

2. The adsorbent according to claim 1, wherein the volume iodine number is 500 mg / cm 3 Up to 550 mg / cm 3 , and the volume molasses number is 150 cm -3 Up to 350 cm -3 .

3. The adsorbent according to claim 1 or 2, wherein the activated carbon or the reactivated carbon is formed from a precursor carbonaceous material selected from one or more of the following: bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, fruit pits, coconut shells, babassu nuts, macadamia nuts, dende nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum asphalt, bagasse, rice husks, corn husks, wheat husks and chaffs, graphene, carbon nanotubes and polymer fibers.

4. The adsorbent according to claim 1 or 2, wherein the activated carbon or the reactivated carbon is formed from one or both of bituminous coal and sub-bituminous coal.

5. The adsorbent of claim 1 or 2, wherein a bed containing the adsorbent is capable of removing PFOA from at least 20,000 bed volumes of water containing PFOA at a concentration of 61 ng / L or less, thereby producing a filtered water stream, wherein the concentration of PFOA detected in the filtered water stream is then 15 ng / L.

6. A method for removing one or more perfluorinated and polyfluoroalkyl substances from a fluid, the method comprising: include: An adsorbent is provided, the adsorbent comprising activated carbon, reactivated carbon or a combination thereof, wherein the activated carbon, reactivated carbon or a combination thereof is reagglomerated, and the adsorbent has a volume iodine number of 450 mg / cm 3 Up to 600 mg / cm 3 , volume molasses number is 150 cm -3 Up to 400 cm -3 , and the apparent density is less than 0.45 cm -3 ;as well as The fluid is contacted with the adsorbent.

7. The method of claim 6, wherein the activated carbon or the reactivated carbon is formed from a precursor carbonaceous material selected from one or more of: bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, fruit pits, coconut shells, babassu nuts, macadamia nuts, palm nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum asphalt, bagasse, rice husks, corn husks, wheat husks and chaff, graphene, carbon nanotubes and polymer fibers.

8. The method of claim 6 or 7, wherein the activated carbon or the reactivated carbon is formed from one or more of bituminous coal and sub-bituminous coal.

9. The method according to claim 6 or 7, wherein the adsorbent has a volume iodine number of 500 mg / cm 3 Up to 550mg / cm 3 , and the volume molasses number is 150 cm -3 Up to 350 cm -3 .

10. The method of claim 6 or 7, wherein the bed containing the adsorbent is capable of removing PFOA from at least 20,000 bed volumes of water containing PFOA at a concentration of 61 ng / L or less, thereby producing a filtered water stream, and the concentration of PFOA detected in the filtered water stream is then 15 ng / L.

11. An adsorbent composition comprising one or more adsorbents and optionally a second adsorbent, the one or more adsorbents comprising activated carbon, reactivated carbon, or a combination thereof, wherein the activated carbon, reactivated carbon, or a combination thereof is reagglomerated, the one or more adsorbents having a volume iodine number of 450 mg / cm 3 and up to 600 mg / cm 3 , volume molasses number is 150cm -3 Up to 400 cm -3 , and the apparent density is less than 0.45 cm -3 .

12. The adsorbent composition of claim 11, further comprising one or more inert materials, fillers, binders, or other compositions not having any appreciable adsorbent capacity.

13. The adsorbent composition according to claim 11 or 12, wherein the volume iodine number is 500 mg / cm 3 Up to 550mg / cm 3 , and the volume molasses number is 150 cm -3 Up to 350 cm -3 .

14. The adsorbent composition of claim 11 or 12, wherein a bed containing the adsorbent composition is capable of removing PFOA from water containing PFOA at a concentration of 61 ng / L or less over at least 20,000 bed volumes, thereby producing a filtered water stream, wherein the concentration of PFOA detected in the filtered water stream is then 15 ng / L.

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