Adsorbent with high volumetric iodine value and high volumetric molasses value for removal of PFAS from fluids and methods of making and using same

Abstract

The present disclosure provides adsorbents and adsorbents that improve adsorption of perfluoroand polyfluoroalkyl species (PFAS). The adsorbents and adsorbents have a microstructure effective to adsorb PFAS, as shown in a combination of high volume iodine number and high volume molasses number. Methods of manufacture and methods of use are further provided.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 2021800492095, application date July 14, 2021, priority date July 14, 2020, and invention name “Adsorbent with high volumetric iodine value and high volumetric molasses value for removing PFAS from fluids and preparation and use methods thereof”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS 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] This 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 that includes perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and compounds produced through the gENX process, such as 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propionate and heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether. These highly fluorinated compounds have enjoyed widespread industrial use for many years due to their chemical durability, excellent surfactant properties, and their key role as precursors to fluoropolymers including polytetrafluoroethylene.

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

[0006] To date, various technologies have been employed to remove PFASs from the environment and drinking water, but none have been entirely satisfactory. For example, some prior art has attempted to remove PFASs by contacting PFAS-containing fluids with various adsorbents. However, prior art fails to explain which chemical and microstructural properties of the adsorbents will or will not result in effective uptake of PFASs. Therefore, there is a need not only for more effective adsorbents that can better remove PFASs from the environment and drinking water, but also for those materials that can be designed to possess the desired chemical and microstructural properties. Summary of the Invention

[0007] The present disclosure provides an adsorbent for removing one or more per- and polyfluoroalkyl substances from a fluid. In one aspect, the present disclosure provides an adsorbent for removing one or more per- and polyfluoroalkyl substances from a fluid, the adsorbent exhibiting a volumetric iodine number of about 450 mg / cm 3 to about 550 mg / cm 3 , and exhibits a volume molasses number of approximately 100 cm -3 to about 400 cm -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 comprises one or both of activated carbon and reactivated carbon, and in any embodiment, the activated carbon or the reactivated carbon can be 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 pitch, bagasse, rice hulls, corn husks, wheat husks and chaff, 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 600 mg / cm 3, and the volume molasses number is about 100 cm -3 to about 400 cm -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, wherein the concentration of PFOA detected in the filtered water stream is about 15 ng / L.

[0014] In another aspect, the present disclosure provides a method for removing one or more perfluoroalkyl and polyfluoroalkyl substances from a fluid, the method comprising: providing an adsorbent having a volume iodine number of at least about 450 mg / cm 3 and a volume molasses number 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 comprises 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 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 pitch, bagasse, rice hulls, 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 600 mg / cm 3 , and the volume molasses number is about 100 cm -3 to about 400 cm -3 .

[0021] In another embodiment, the adsorbent has a volume iodine number of about 500 mg / cm 3to about 550 mg / cm 3 , and the volume molasses number is about 110 cm -3 to about 350 cm -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, wherein the concentration of PFOA detected in the filtered water stream is 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 molasses number 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 600 mg / cm 3 , and the volume molasses number is about 100 cm -3 to about 400 cm -3 .

[0026] In another embodiment, the adsorbent has a volume iodine number of about 500 mg / cm 3 to about 550 mg / cm 3 , and the volume molasses number is about 110 cm -3 to about 350 cm -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: Figure 1An example of a decolorization curve for a sample of an adsorbent as disclosed herein is provided.

[0029] Figure 2 Depicted are UV-Vis transmittance spectra collected from a sample of the filtrate of a molasses solution after treatment with activated carbon.

[0030] 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 passed through the bed is provided.

[0031] Figure 4A Scatter 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 the water reaching 25% of the PFOA concentration in the untreated water at the outlet port of the bed are provided.

[0032] 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

[0033] The present disclosure is not limited to the specific systems, devices, and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope.

[0034] 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."

[0035] 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" refers to the specified temperature ± 5 degrees.

[0036] 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.

[0037] 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.

[0038] As used herein, the term "per- and polyfluoroalkyl substances (PFAS)" means any per- or polyfluoroalkyl substance, mixture of such substances, or derivative of one or more such substances. Examples of per- and polyfluoroalkyl substances include perfluoroalkyl sulfonates, perfluoroalkanesulfonic acid (PFSA), N-butylperfluoroalkanesulfonamide (BuFASA), N-butylperfluoroalkanesulfonamidoethanol (BuFASE), N-butylperfluoroalkanesulfonamidoacetic acid (BuFASAA), N-ethylperfluoroalkanesulfonamide (EtFASA), N-ethylperfluoroalkanesulfonamidoethanol (EtFASE), N-ethylperfluoroalkanesulfonamidoacetic acid (EtFASAA), perfluoroalkanesulfonamide (FASA), perfluoroalkanesulfonamidoethanol (FASE). , perfluoroalkanesulfonamidoacetic acid (FASAA), N-methylperfluoroalkanesulfonamide (MeFASA), N-ethylperfluoroalkanesulfonamidoacetic acid (MeFASAA), N-methylperfluoroalkanesulfonamidoethanol (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 perfluorooctanesulfonamide (MeFOSA), perfluorooctanoic acid (PFOA), perfluorooctanesulfonate, perfluorooctanesulfonic acid (PFOS), 2,3,3,3,-tetrafluoro-2-(heptafluoropropoxy)propionate, 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propionate, ammonium 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 (8:2 Perfluorobutyric acid (PFBA), perfluorobutanesulfonate, perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonate, perfluorohexanesulfonic acid (PFHxS), perfluorohexanoate, perfluorohexanoic acid (PFHxA), 4,8-dioxa-3H-perfluorononanoate, ammonium perfluorooctanoate (APFO), N-ethylperfluorooctanesulfonamide (EtFOSA), N-ethylperfluorooctanesulfonamidoethanol (EtFOSE), perfluorooctanesulfonamide (PFOSA), perfluorooctanesulfonamidoacetic acid (FOSAA), perfluorooctanesulfonamidoethanol (FOSE), perfluorobutyrate, perfluorobutyric acid, perfluorobutyrate, perfluorobutyric acid, perfluoroalkyl carboxylates, perfluoroalkyl carboxylic acids (PFCA), perfluorodecanoate, perfluorodecanoic acid (PFDA), perfluorododecanoate, perfluorododecanoic acid (PFDoA), perfluorododecanesulfonic acid perfluorooctanoate, perfluorophosphonic acid (PFPA), perfluoropentanoate, perfluoropentanoic acid (PFPeA), perfluoropentanesulfonate, perfluoropentanesulfonic acid (PFPeS), perfluorophosphinic acid (PFPiA), perfluorotetradecanoic acid (PFTeDA), perfluorotridecanoic acid (PFTrDA), perfluoroundecanoate, perfluoroundecanoic acid (PFUnA), perfluoro-n-decanesulfonate (PFUnS), perfluoro-n-decanesulfonic acid (PFUnSA), and polytetrafluoroethylene (PTFE).

[0039] As used herein, "iodine number" or "IV" refers to either the weight or volumetric 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.

[0040] As used herein, "weight iodine number" or "IV g "Iodine Number by Weight" refers to a characteristic of an adsorbent formed from a carbonaceous material as determined by the industry standard test ASTM D4607-14. Weight Iodine Number is reported in units of mass of iodine adsorbed per mass of adsorbent.

[0041] 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 previous paragraph. Volume iodine number is reported as mass of iodine adsorbed per volume of adsorbent.

[0042] 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.

[0043] As used herein, "weight molasses number" or "MN g "" means the decolorization capacity of an adsorbent as determined 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. Weight Molasses Number is reported as a unitless amount per mass of adsorbent.

[0044] As used herein, "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 per volume of adsorbent.

[0045] Adsorbents and adsorbent compositions 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 ( For example About 450 mg / cm 3 to about 600 mg / cm 3 ), and exhibiting a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm -3 ).

[0046] Advantageously, the volume iodine number is at least about 450 mg / cm 3 and a volume molasses number of at least about 100 cm -3The adsorbent can exhibit good adsorption of 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 500 mg / cm 3 , about 470 mg / cm 3 to about 550 mg / cm 3 , about 500 mg / cm 3 to about 550 mg / cm 3 , about 520 mg / cm 3 to about 550 mg / cm 3 or about 490 mg / cm 3 to about 520 mg / cm 3 The aforementioned values ​​and ranges may be used individually or in combination, and any range may be formed by selecting two or more of the aforementioned end values.

[0047] 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 , about 110 cm -3 , about 120 cm -3 , about 130 cm -3 , about 140 cm -3 , about 150 cm -3 , about 160 cm -3 , about 170 cm -3 , about 180 cm -3 , about 190 cm -3 , about 200 cm -3 , about 210 cm -3 , about 220 cm-3 , about 230 cm -3 , approximately 240 cm -3 , about 250 cm -3 , about 260 cm -3 , approximately 270 cm -3 , about 280 cm -3 , about 290cm -3 , about 300 cm -3 , about 310 cm -3 , about 320 cm -3 , about 330 cm -3 , approximately 340 cm -3 , about 350 cm -3 , about 360 cm -3 , about 370 cm -3 , about 380 cm -3 , approximately 390 cm -3 , about 400 cm -3 Or any range by selecting two or more of the above values ​​as end values.

[0048] 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 0.95 g / cm 3 , less than about 0.90 g / cm 3 , less than about 0.85 g / cm 3 , less than about 0.80 g / cm 3 , less than about 0.75 g / cm 3 , less than about 0.70 g / cm 3 , less than about 0.65 g / cm 3 , less than about 0.60 g / cm 3 , less than about 0.55 g / cm 3 , less than about 0.50 g / cm 3 , less than about 0.45 g / cm 3 , less than about 0.40 g / cm 3 or less than about 0.35 g / cm 3 In any embodiment, the adsorbent may have an apparent density of about 1.00 g / cm 3 , about 0.95 g / cm 3 , about 0.90 g / cm 3 , about 0.85g / cm 3 , about 0.80 g / cm 3 , about 0.75 g / cm 3, about 0.70 g / cm 3 , about 0.65 g / cm 3 , about 0.60 g / cm 3 , about 0.55g / cm 3 , about 0.50 g / cm 3 , about 0.45 g / cm 3 , about 0.40 g / cm 3 , about 0.35 g / cm 3 , about 0.30 g / cm 3 or any range by selecting two or more of the above values ​​as endpoints. In any embodiment, the apparent density of the adsorbent can be about 0.30 g / cm 3 to about 1.00 g / cm 3 , about 0.30 g / cm 3 to about 0.95 g / cm 3 , about 0.30 g / cm 3 to about 0.90 g / cm 3 , about 0.30 g / cm 3 to about 0.85 g / cm 3 , about 0.30 g / cm 3 to about 0.80 g / cm 3 , about 0.30 g / cm 3 to about 0.75 g / cm 3 , about 0.30 g / cm 3 to about 0.70 g / cm 3 , about 0.30 g / cm 3 to about 0.65 g / cm 3 , about 0.30 g / cm 3 to about 0.60 g / cm 3 , about 0.30 g / cm 3 to about 0.55 g / cm 3 , about 0.30 g / cm 3 to about 0.50 g / cm 3 , about 0.30 g / cm 3 to about 0.45 g / cm 3 , about 0.30 g / cm 3 to about 0.40 g / cm 3 or about 0.30 g / cm 3 to about 0.35 g / cm 3 .

[0049] The adsorbent composition may include one or more adsorbents, each adsorbent comprising 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 comprising one or more adsorbents may comprise or be derived from a single type of adsorbent medium, or may be combined with adsorbents comprising or derived from one or more additional types of adsorbent media or non-adsorbent media. In embodiments where the adsorbent composition comprises two or more types of adsorbents, the two or more adsorbents may be mixed together and may comprise or be derived from the same or different precursor materials selected from the aforementioned materials.

[0050] 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 pitch, bagasse, rice hulls, corn husks, wheat hulls and chaff, 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.

[0051] 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, referred to as "powdered activated carbon" or "PAC," a granular form, referred to as "granular activated carbon" or "GAC," or a pelletized form, 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 (having openings of approximately 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 (having openings of approximately 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.

[0052] In any embodiment, the adsorbent composition may include a bulk iodine number of at least about 450 mg / cm 3 and a volume molasses number of at least about 100 cm -3 The adsorbent composition may further comprise at least one compound that is not an adsorbent and that does not substantially absorb or adsorb per- and polyfluoroalkyl substances or any other compound.

[0053] 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 molasses number 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, metal, ceramic, clay, glass or a combination of one or more of the above is commonly used. Taking organic binders as an example, petroleum resin and / or asphalt, natural resin and / or asphalt, polymer or a combination of one or more of the above is commonly used.

[0054] In any embodiment, the invention comprises a volume iodine number of at least about 450 mg / cm 3 and a volume molasses number of at least about 100 cm -3 The adsorbent composition of one or more adsorbents can be provided in a container. The container can hold a volumetric iodine number of at least about 450 mg / cm 3 and a volume molasses number of at least about 100 cm -3 an adsorbent composition of one or more adsorbents configured and sized to receive a fluid ( Right now, liquid or gas) and conveying the fluid through or through the 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 within the device 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 with 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 the 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.

[0055] In another example, and in any embodiment, the container itself can be designed to be quickly replaced with minimal changes to external components, such as pumps and conduits that deliver liquids or gases to the container. In such embodiments, the container can be referred to as a "cartridge," and it can be connected and disconnected from surrounding components. In any embodiment, the cartridge can be disposable, as in consumer drinking water applications. Alternatively, in another example, and in any embodiment, the cartridge can be intended to be refurbished, wherein the cartridge containing the spent sorbent is returned for cleaning or reactivation of the sorbent, refilled with fresh original or reactivated sorbent, and returned to use after the refurbishment operation is complete.

[0056] Preparation method The adsorbent composition comprises an adsorbent effective in removing per- and polyfluoroalkyl substances and exhibiting a volumetric iodine number of at least about 450 mg / cm 3 ( For example About 450 mg / cm 3 to about 600 mg / cm 3 ), and exhibiting a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm -3 ) of one or more adsorbents.

[0057] A volume iodine number of at least about 450 mg / cm 3 and a volume molasses number 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.

[0058] Granular activated carbon or reactivated carbon can be formed by crushing a precursor carbonaceous material into a powder of a desired size. The powder may optionally be mixed with a binder. The crushed material, optionally together with a binder, may then be formed into agglomerates, which may then be ground into particles of a desired size. The resulting granular material may then be carbonized to modify its properties, such as, but not limited to, removing volatile compounds and activating the precursor carbonaceous material.

[0059] 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.

[0060] Adsorbents made from activated 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 ( For example About 450mg / cm 3 to about 600 mg / cm 3 ), and a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm -3 ).

[0061] For example, activated carbon can be formed by oxidizing and devolatilizing a raw carbonaceous material 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 ( example like , weight iodine number, weight molasses number). In any embodiment, the initial oxidation and devolatilization process can include chemical treatment with dehydrating chemicals such as phosphoric acid, sulfuric acid, sodium hydroxide, potassium hydroxide, and combinations of these.

[0062] In another example, suitable activated carbon can be formed by a direct activation process. Such activated carbon adsorbents are sometimes referred to as directly activated carbon. In the 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.

[0063] 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 recover at least some of the original adsorbent capacity. Any of the adsorbents listed above may be reactivated after depletion, and 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 made 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 be volatilized or pyrolyzed from the activated carbon to form a carbonaceous char. The heating may occur at temperatures above about 500°C ( For example , about 500°C to about 1100°C), more specifically above about 700°C ( For example , about 700°C to about 1100°C), and the resulting reactivated carbon can then be reused for various purposes, including water treatment.

[0064] While any process may be used to produce a volumetric iodine number of at least about 450 mg / cm 3 ( For example About 450 mg / cm 3 to about 600 mg / cm 3 ) and a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm -3 ) adsorbents, but the following observations may provide useful guidance to those skilled in the art because the volumetric iodine number and volumetric 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 weight molasses number, but at the same time 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 weight molasses number may not increase the volumetric iodine number and volumetric molasses number beyond a certain value. Taking all of the above into consideration, the present disclosure describes adsorbents that maximize both the volumetric iodine number and the volumetric molasses number to achieve excellent performance.

[0065] Although the adsorbents of the present disclosure are primarily disclosed for the removal of per- and polyfluoroalkyl substances or chemically similar or chemically related compounds, the use of the adsorbents is not limited thereto. In still further 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 throughout this application as "taste and odor compounds." 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).

[0066] 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 type of molecules the adsorbent is effective at adsorbing. After intensive experimentation, applicants determined that a volume iodine number of at least about 450 mg / cm 3 ( For example About 450 mg / cm 3 to about 600 mg / cm 3 ) and a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm -3 ) do not meet the requirements for good adsorbents / adsorbent capacity for a wide range of PFAS. Along the same lines, a material with a very high measurement of either the Gravimetric Iodine Number or the Gravimetric Molasses Number cannot compensate for a lower measurement of the other. Applicants have also determined that volumetric rather than gravimetric measurements 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.

[0067] How to use Advantageously, the volume iodine number formed by the process described herein is at least about 450 mg / cm 3 ( For example About 450mg / cm 3 to about 600 mg / cm 3 ) and a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm-3 ) of the adsorbent so that it can be absorbed by water ( For example It has excellent performance in removing one or more perfluorinated and fluoroalkyl species from fluids such as drinking water.

[0068] Thus, provided herein is a method for removing one or more perfluoroalkyl substances from a fluid, the method comprising contacting a fluid containing one or more perfluoroalkyl substances compounds with an adsorbent composition comprising one or more adsorbents disclosed herein. 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 ( For example About 450 mg / cm 3 to about 600 mg / cm 3 ), and exhibiting a volume molasses number of at least about 100 cm -3 ( For example , about 100 cm -3 to about 400 cm -3 ).

[0069] The contact method is not particularly limited. For example, in any embodiment, the stream comprising the fluid can pass through or pass through a bed comprising an adsorbent composition comprising 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 the desired amount of one or more perfluoro and polyfluoroalkyl substances 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.

[0070] Examples Before describing the examples, a complete description of the test methods must be given.

[0071] Determination of iodine number (IV) The gravimetric iodine number of the activated carbon sample was measured according to ASTM D4607- 14. The gravimetric iodine number was reported in milligrams of iodine adsorbed per gram of activated carbon sample.

[0072] To calculate the volume 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.

[0073] Determination of weight molasses number (MN g ) To determine the gravimetric molasses number, Calgon Carbon Corporation Test Method Number TM-3 (“TM-3”) was utilized. TM-3 is designed to measure 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 using ASTM D2854-09 (2019). v The weight molasses number was determined by TM-3 as follows: Limitations: The concentration of the molasses solution used for testing depends on the standard carbon. As used herein, "standard carbon" is an activated carbon adsorbent that is a reference material characterized by its weight molasses number. As understood by practitioners skilled in the art, "200 standard carbon" is expected to produce a weight molasses number of 200, "250 standard carbon" is 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 for a product encompasses 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 a manufacturing instruction. The molasses solution must not be diluted. A fixed optical path length of 2.5 mm must be used.

[0074] As will be understood by those skilled in the art, standard carbon is not limited, provided that the standard carbon is a reference material suitable for the molasses number. An example of 400 standard carbon is "RB," which is available from Calgon Carbon Corporation of Moon Township, PA. RB is a powdered, steam-activated carbon made from bituminous coal having 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 having 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 Corporation 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 the particles are sieved through 325 mesh or less than 44 μm in size. A third example of 230 standard carbon is "BL," available from Calgon Carbon Company of Moon Township, Pennsylvania. BL is a powdered steam-activated carbon made from bituminous coal with 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 60-75 wt.% of the particles are sieved through 325 mesh or less than 44 μm in size.

[0075] Principle: A blackstrap molasses solution is treated with a standard carbon with a known molasses number ("molasses standard carbon"), filtered, and the filtrate analyzed by UV-vis spectrophotometry to generate a relationship between molasses number and absorbance. The blackstrap molasses solution is then treated with a carbon sample of unknown decolorization capacity / unknown molasses number ( For example , adsorbents provided herein) were treated, filtered, and the filtrate analyzed in the same manner. Right now , decolorization), the brighter the filtrate will be, and conversely, the lower the absorbance. Therefore, a higher molasses number corresponds to a higher decolorization capacity, 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 spectrum of a representative filtrate is depicted). The molasses number for each sample was calculated from the ratio of the absorbance values ​​of the sample and the carbon standard: Molasses number = (A × B) / C Where A is the molasses number of a standard carbon with a known molasses number; B is the average absorbance of three measurements of a standard carbon with a known molasses number; and C is the absorbance of the sample analyzed ( Right now , the absorbance of the filtrate of the adsorbent with unknown molasses number).

[0076] 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.

[0077] The instruments used in TM-3 are described in Table 1 below: Table 1

[0078] The reagents used in TM-3 are described in Table 2 below: Table 2

[0079] Prepare a blackstrap molasses solution ("standardized molasses solution") for determining the molasses number according to the following procedure: 1. Weigh about 50g of blackstrap molasses into a clean, dry beaker and set aside until the water is heated to 95°C.

[0080] 2. Using a graduated cylinder, add 1000 mL of ASTM Type 2 water to a stainless steel beaker.

[0081] 3. Cover the beaker with aluminum foil or a large glass lid, place it on a hot plate, and heat to 95°C.

[0082] 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.

[0083] 5. Cool the solution to room temperature (approximately 25°C).

[0084] 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 initiate the siphon. Siphon the solution into a separate container (e.g., a large glass bottle).

[0085] 7. Discard the remaining contents of the beaker. Store the molasses solution in the refrigerator for up to 24 hours. Keep the molasses solution on ice while running the test method.

[0086] 8. Weigh 0.46 ± 0.0002 g of 250 molasses carbon standard into a clean, dry 400 mL beaker.

[0087] 9. Pipette 50 mL of molasses solution into the beaker. Vortex the beaker while adding the molasses solution until the 250% molasses carbon standard is completely wetted.

[0088] 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.

[0089] 11. Filter the sample through a Buchner funnel using the previously prepared WHATMAN® No. 3 filter paper under vacuum. Cover the filtrate with approximately 20 mL of the solution and discard this filtrate. Filter the remainder.

[0090] 12. Measure and record the absorbance of the filtrate at 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").

[0091] 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, measure the volume of the remaining molasses solution, multiply by 0.640, and further multiply by the absorbance recorded from step 12. Subtract this value from the total volume of the molasses solution, resulting in the required volume of water added to the molasses solution. Add water and mix the solution thoroughly. Repeat steps 8-13 until the absorbance values ​​(at 472 nm) of three consecutive analyzed samples are between 0.630 and 0.650.

[0092] 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 add, measure the volume of the molasses solution, multiply by 0.640, and further multiply by the absorbance recorded from step 12. Subtract this value from the total volume of the molasses solution and divide by 10. The result represents the amount (by weight) of molasses that should be added to the molasses solution. Add the required amount of molasses to a small glass beaker. Add approximately 25 mL of molasses solution to the beaker to dissolve the molasses. Heat the beaker to 90°C on a hot plate and then cool slightly. 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.

[0093] 400 standard carbon standardization 15. Weigh 0.46 ± 0.0002 g of 400 molasses carbon standard into a clean, dry 400 ml beaker.

[0094] 16. Pipette 50 mL of molasses solution into the beaker. Vortex the beaker while adding the molasses solution until the carbon is completely wetted.

[0095] 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 start a stopwatch. Remove the thermocouple or thermometer and boil the solution for 30 seconds.

[0096] 18. Filter the sample using a Buchner funnel under vacuum using the previously prepared WHATMAN® No. 3 filter paper. Cover the filtrate with approximately 20 mL of the solution and discard this filtrate. Filter the remaining 30 mL portion and use the filtrate for subsequent measurements.

[0097] 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.

[0098] 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, measure the volume of the remaining molasses solution, multiply by 0.400, and further multiply by the absorbance recorded from step 19. Subtract this value from the total volume of the molasses solution, resulting in the required volume of water added to the molasses solution. Add water and mix the solution thoroughly. Repeat steps 8-13 until the absorbance values ​​(at 472 nm) of three consecutive samples are measured between 0.390 and 0.410.

[0099] 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 add, measure the volume of the molasses solution, multiply by 0.640, and further multiply by the absorbance recorded from step 19. Subtract this value from the total volume of the molasses solution and divide by 10. The result represents the amount (by weight) of molasses that should be added to the molasses solution. Add the required amount of molasses to a small glass beaker. Add approximately 25 mL of molasses solution to the beaker to dissolve the molasses. Heat the beaker to 90°C on a hot plate and then cool slightly. 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 0.640 and 0.640 are obtained, thereby creating a standardized molasses solution for subsequent use.

[0100] Sample analysis The samples were analyzed according to the following procedure: 1. Prepare a carbon sample of unknown molasses content and grind it until 95% or more of the molasses passes through a 325-mesh sieve. If the sample is not from a recent production, dry it at 150°C to a constant weight before use. Prepare an internal carbon standard in the same manner. Grind equal amounts to ensure that the materials are of comparable fineness.

[0101] 2. Weigh a 0.46 ± 0.0002 gram portion of the dried pulverized carbon sample into a separate clean and dry 400 mL beaker.

[0102] 3. Prepare the filtration setup for sample filtration. Place a WHATMAN® No. 3 filter ring in a Büchner funnel. Connect the funnel to a 250 mL filter flask and initiate vacuum filtration. Add 50 mL of the filter paper suspension, ensuring that the entire surface of the filter paper ring is coated. Once all liquid has drained, discard the filtrate collected in the filter flask.

[0103] 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.

[0104] 5. Place the beaker on a hot plate and place a thermocouple or thermometer in the beaker so that the tip is resting on the bottom of the beaker. Heat the solution until the thermocouple reads 98°C and start a stopwatch. Remove the thermocouple or thermometer and boil the solution for 30 seconds.

[0105] 6. Filter the sample by vacuum through a Buchner funnel using the WHATMAN® No. 3 filter paper prepared previously in step 3. Cover the filter with approximately 20 mL of sample and discard this filtrate. Filter the remainder.

[0106] 7. Measure and record the absorbance of the filtrate at 472 nm using a 2.5 mm fixed pathlength KLETT™ Summerson cell. Use deionized or distilled water as a reference.

[0107] 8. The molasses number is calculated as follows: Molasses number = (A × B) / C Wherein 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.

[0108] 9. Report the molasses number to the nearest increment of ten using conventional rounding techniques. ( For example 226 = 230) Example 1 For Example 1, a 12 x 40 sample of granular activated carbon was prepared for use in a fixed or moving bed for the purification and decolorization of aqueous and organic liquids. The sample was reagglomerated activated carbon formed from bituminous coal. The bituminous coal was first crushed into a powder, and a binder was subsequently added to the powder. The powder and binder were then reagglomerated into agglomerates. After agglomeration, the agglomerates were crushed and sized. The sizing process retained only particle sizes between 12 mesh (1.70 mm pore size) and 40 mesh (0.425 mm pore size). Note that as described herein, mesh sizes are based on US mesh sizes. The average particle size of the sample batch was between 0.9 mm and 1.1 mm, and the amount of granular activated carbon with a particle size greater than 12 mesh (1.70 mm) did not exceed 5.0 wt.%. The amount of granular activated carbon with a particle size less than 40 mesh (0.425 mm) did not exceed 4 wt.%. The crushed and sized particles were carbonized and then thermally activated. After thermal activation, the granular activated carbon of Example 1 had a moisture content of less than 2 wt.% as measured by ASTM D2867, an abrasion value of 75 as measured by AWWA B604, and an apparent density of 0.49 g / cm3 as measured by ASTM D2854-09. 3 .

[0109] Example 2 A sample of reagglomerated granular activated carbon was prepared in the same manner as described in Example 1, except that activation was performed so that the resulting product had an apparent density of 0.42 g / cm 3 .

[0110] Example 3 A sample of reagglomerated granular activated carbon was prepared in the same manner as described in Example 1, except that activation was performed so that the resulting product had an apparent density of 0.38 g / cm 3 .

[0111] Comparative Example 1 (C1) A sample of granular activated carbon was prepared for Comparative Example 1. In Comparative Example 1, the sample was an activated carbon formed from coconut shells. The coconut shells were first processed by slow pyrolysis to form the charcoal. Sizing was performed according to ASTM D2862-16 to retain only particle sizes between 12 mesh (1.70 mm pore size) and 40 mesh (0.425 mm pore size). The amount of granular activated carbon having a particle size greater than 12 mesh (1.70 mm) was no more than 5 wt.%. The amount of granular activated carbon having a particle size less than 40 mesh (0.425 mm) was no more than 4 wt.%. The sized particles were then activated. The resulting granular activated carbon had a hardness value of at least 95 as measured by ASTM D3802. The resulting granular activated carbon had an apparent density of 0.48 g / cm as measured by ASTM D2854. 3 .

[0112] Comparative Example 2 (C2) A sample of granular activated carbon was prepared for Comparative Example 2. In Comparative Example 2, the sample was a reagglomerated activated carbon formed from bituminous coal. The bituminous coal was first crushed into a powder, and a binder was subsequently added to the powder. The powder and binder were then reagglomerated into agglomerates. After agglomeration, the agglomerates were crushed and sized. Sizing was performed according to ASTM D2862-16 to retain only particle sizes between 12 mesh (1.70 mm pore size) and 40 mesh (0.425 mm pore size). The amount of particles larger than 12 mesh (1.70 mm) did not exceed 5 wt.%. The amount of particles smaller than 40 mesh (0.425 mm) did not exceed 4 wt.%. The crushed and sized agglomerates were then carbonized and then thermally activated. The hardness value measured by ASTM D3802 was at least 75. The apparent density measured by ASTM D2854 was 0.54 g / cm 3 .

[0113] Comparative Example 3 (C3) Samples prepared from a commercially sourced lignite-based granular activated carbon were also tested. HYDRODARCO 4000 is a lignite-based granular activated carbon that was sized according to ASTM D2862-16 to retain only particle sizes between 12 mesh (1.70 mm pore size) and 40 mesh (0.425 mm pore size). The amount of granular activated carbon with a particle size larger than 12 mesh (1.70 mm) did not exceed 5 wt.%. The amount of granular activated carbon with a particle size smaller than 40 mesh (0.425 mm) did not exceed 4 wt.%.

[0114] Comparative Example 4 (C4) Samples prepared from commercially available activated carbons were tested. The activated carbon of Comparative Example 4 was a granular activated carbon formed by direct activation of bituminous coal.

[0115] result Examples 1-3 and Comparative Examples 1-4 were tested for their effectiveness in removing specified PFASs. Six beds were prepared according to ASTM D6586, each consisting solely of activated carbon from each of Examples 1-3 and Comparative Examples 1-3. Testing was performed according to EPA Method 537, Version 1.1, which measures the adsorption of contaminants by granular activated carbon in aqueous systems using the Rapid Small Scale Column Test (RSSCT), prepared as described above. A water supply was passed through the beds, and the PFAS concentration at the outlet was measured at specified intervals. To normalize for bed size, results are reported in units of "bed volume," which is the volume of water passed through the activated carbon bed divided by the volume of the bed itself. During testing, the point at which 25% of the PFAS concentration "breaks through" the activated carbon bed was noted. For a given adsorbent, a higher bed volume at 25% breakthrough means that the same amount of adsorbent adsorbs a greater amount of PFAS and is therefore more effective.

[0116] In the results, PFOA is perfluorooctanoic acid (also known as pentafluorooctanoic acid or simply C8 by the IUPAC nomenclature). 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 contaminant PFOA at a concentration of at least 25% "penetrated" the activated carbon bed, i.e., 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 contaminant 4:2 FtS at a concentration of at least 25% "penetrated" the activated carbon bed. 4:2 FtS is a 4:2 fluorotelomer sulfonic acid and is a per- 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: Table 3

[0117] The results are still Figure 3 、 4A and shown in 4B. Figure 3 The normalized concentration of PFOA measured in the column effluent is plotted against the number of bed volumes of water 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.

[0118] Figure 4A The horizontal axis plots the bed volume number until 25% PFOA penetrates the activated carbon adsorbent bed. 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 exhibits 25% PFOA penetration at approximately 10,000 bed volumes. The volumetric molasses number for this 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 volumetric iodine number and volumetric molasses number corresponding to each sample are provided.

[0119] 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. 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 100 cm -3 The second correlation is performed on all data points of those data points, then R 2 The value increases 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, the adsorbent having a volume iodine number of at least about 450 mg / cm 3 and a volume molasses number of at least about 100 cm -3 .

2. The adsorbent according to claim 1, wherein the volume iodine number is about 500 mg / cm 3 to about 550 mg / cm 3 , and the volume molasses number is about 110 cm -3 to about 350 cm -3 .

3. The adsorbent according to claim 1 or claim 2, wherein the adsorbent comprises one or more of the following: carbonaceous carbon, activated carbon, reactivated carbon and carbon black.

4. The adsorbent according to claim 3, wherein the adsorbent comprises one or both of activated carbon and reactivated carbon.

5. The adsorbent of claim 4, 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, dende nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitch, bagasse, rice hulls, corn husks, wheat hulls and chaff, graphene, carbon nanotubes, and polymer fibers.

6. The adsorbent according to any one of claims 3 to 5, wherein the activated carbon or the reactivated carbon is formed from one or both of bituminous coal and sub-bituminous coal.

7. The adsorbent according to any one of claims 3 to 6, wherein the activated carbon or the reactivated carbon is reagglomerated.

8. The adsorbent according to any one of claims 1 to 7, wherein the volume iodine number is about 450 mg / cm 3 to about 600 mg / cm 3 , and the volume molasses number is about 100 cm -3 to about 400 cm -3 .

9. The adsorbent of any one of claims 1 to 8, wherein a bed containing the adsorbent is capable of removing PFOA from water containing PFOA at a concentration of about 61 ng / L or less over at least about 20,000 bed volumes, thereby producing a filtered water stream, wherein the concentration of PFOA detected in the filtered water stream is then about 15 ng / L.

10. A method of removing one or more per- and polyfluoroalkyl substances from a fluid, the method comprising: Providing an adsorbent having a volume iodine number of at least about 450 mg / cm 3 and a volume of molasses of at least about 100 cm -3 ;as well as The fluid is contacted with the adsorbent.

11. The method of claim 10, wherein the adsorbent comprises one or more of: carbonaceous carbon, activated carbon, reactivated carbon, and carbon black.

12. The method of claim 10 or 11, wherein the adsorbent comprises one or both of activated carbon or reactivated carbon.

13. The method of claim 12, 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 pitch, bagasse, rice hulls, corn husks, wheat husks and chaff, graphene, carbon nanotubes, and polymer fibers.

14. The method of claim 12 or claim 13, wherein the activated carbon or the reactivated carbon is formed from one or more of bituminous coal and sub-bituminous coal.

15. The method according to any one of claims 12 to 14, wherein the activated carbon or the reactivated carbon is reagglomerated.

16. The method of any one of claims 10 to 15, wherein the volume iodine number is about 450 mg / cm 3 to about 600 mg / cm 3 , and the volume molasses number is about 100 cm -3 to about 400 cm -3 .

17. The method of any one of claims 10 to 16, wherein the adsorbent has a volume iodine number of about 500 mg / cm 3 to about 550 mg / cm 3 , and the volume molasses number is about 110 cm -3 to about 350 cm -3 .

18. The method of any one of claims 10 to 17, wherein the bed containing the adsorbent is capable of removing PFOA from water containing a PFOA concentration of about 61 ng / L or less over at least about 20,000 bed volumes, thereby producing a filtered water stream, wherein the concentration of PFOA detected in the filtered water stream is about 15 ng / L.

19. 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 molasses number of at least about 100 cm -3 .

20. The adsorbent composition of claim 19, further comprising one or more inert materials, fillers, binders, or other compositions without any appreciable adsorbent capacity.

21. The adsorbent composition according to any one of claims 19 or 20, wherein the volume iodine number is about 450 mg / cm 3 to about 600 mg / cm 3 , and the volume molasses number is about 100 cm- 3 to about 400 cm -3 .

22. The adsorbent composition according to any one of claims 19 to 21, wherein the volume iodine number is about 500 mg / cm 3 to about 550 mg / cm 3 , and the volume molasses number is about 110 cm -3 to about 350 cm -3 .

23. The adsorbent composition of any one of claims 19 to 22, wherein a bed containing the adsorbent composition is capable of removing PFOA from water containing a PFOA concentration of about 61 ng / L or less over at least about 20,000 bed volumes, thereby producing a filtered water stream, wherein the concentration of PFOA detected in the filtered water stream is about 15 ng / L.

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