Functionalized alumina sorbent materials for removing contaminants from water

Abstract

A composition for removing target substances from a fluid stream is provided. The composition can be used to remove polyfluorinated alkyl substances (PFAS) from water. The composition includes a support material including alumina and a sorbent molecule including a core polymer, the core polymer being covalently bonded to the support material, and the sorbent molecule further including one or more covalently bonded sorbent groups. A process for removing target substances such as PFAS is also provided.

Description

[Technical field]

[0001] The present invention relates to the removal of target substances from liquids such as water using alumina-based substrate materials chemically modified with polyamines and methods of producing such materials. The present invention further relates to materials for water treatment, sorbent media, amine surface functionalization, hydrophobic interactions, per- and polyfluoroalkyl substances (PFAS), water contaminants and filtration devices. [Background technology]

[0002] There is a continuing need to remediate and recycle contaminated supplies of important fluid solvents such as water. Existing resources need to be reused and replenished rather than simply disposed of. Global environmental protection regulations are also requiring water supplies threatened with contamination from industrial activities to meet ever more stringent purity standards. One such standard is NSF-53, established by the National Sanitary Foundation International, which sets criteria for adsorption / filtration that occurs when liquids, gases or dissolved / suspended substances are deposited on the surface or within the pores of the adsorbent media. Carbon filters containing powdered carbon or activated carbon are examples of media types used in NSF-53 compliant water filtration products.

[0003] There are many different sources of pollutants that harm the environment, including improperly disposed wastewater from industrial plants and chemical processing facilities, surface runoff containing fertilizers and pesticides used in agricultural areas, and flame retardants used in cleaning detergents and fire-fighting foams. Many industrial chemical pollutants can persist in nature for decades before breaking down, and even very low concentrations can cause significant harm to plants, animals, and humans. The impacts on ecosystems are also serious, and persistent pollutants often concentrate in organisms as they move up the food chain.

[0004] One particular class of persistent environmental pollutants includes halogenated organic compounds, such as poly- and perfluorinated alkyl substances (PFAS). PFAS are organofluorine compounds that are considered chemically inert. They persist in the environment and their use is regulated in many countries by the United Nations Framework Convention on Climate Change, the Kyoto Protocol, and REACH. Perfluorooctane sulfonate (PFOS) and its derivatives are subject to the Stockholm Convention and restricted in the EU under the Persistent Organic Pollutants (POPs) Regulation. PFOS and perfluorooctanoic acid (PFOA) are toxic PFAS compounds that are used extensively as surfactants and as flame retardants in firefighting foams and in metal plating processes. Both PFOS and PFOA persist in the environment for very long periods of time and are recognized contaminants in most of the world's freshwater supplies.

[0005] Adsorption of PFAS compounds, such as PFOS and PFOA, onto granular or powdered activated carbon has become the current recommended solution for their removal from contaminated water. However, the process is slow and inefficient. In particular, shorter chain PFAS contaminants "break through" the activated carbon bed quickly, so large amounts of activated carbon are required and must be replaced frequently once saturated with PFAS. Currently, adsorbed PFAS cannot be efficiently washed off the activated carbon for "in situ" regeneration. In addition, a significant percentage of activated carbon produced worldwide is derived from fossil fuels, such as bituminous coal, which is activated through a physical process and releases significant amounts of carbon dioxide. As such, activated carbon has become an expensive, unsustainable, single-use solution to the problem of removing PFAS from contaminated water. Ion exchange methods are also commonly used, but such methods also have a large carbon footprint and reliability is again an issue due to breakthrough. Useful life and cost-effectiveness are also issues with ion exchange-based resins.

[0006] Previous efforts to remove PFAS contaminants from water include, for example, the use of cellulosic support materials functionalized with high molecular weight polyamines, such as polyethyleneimine (PEI, typically 25 kDa), in combination with hydrophobic groups (see WO 2017 / 203281). Such approaches rely primarily on the adsorbent activity of the functional groups, rather than any specific contribution from the supporting substrate material.

[0007] Alumina-based filtration membranes for the removal of perfluoroalkyl species from water have also been proposed using alumina functionalized with linear fluorinated silanes containing 13-17 fluorine atoms (Johnson et al. ACS Omega, 2019, 4, 8001). Such membranes have shown high levels of specificity for removing PFAS from contaminated water, but the amphiphilic silane molecules used as sorbent molecules need to be synthesized. This creates problems in itself, since the perfluorinated waste generated during the synthesis of such sorbent filtration membranes is greater than the actual amount of PFAS removed by the membranes during use. Thus, the improvement in performance is offset by the environmental costs and resulting commercial inviability of this approach. Summary of the Invention [Problem to be solved by the invention]

[0008] There is a need to provide economical and reusable compositions and processes that allow for the removal of low concentrations (<1 ppm) of target materials, particularly contaminants such as PFAS from fluid streams, such as wastewater, or within the broader environment. The present invention seeks to meet these objectives and overcome current challenges, including reducing the impact of industrial activities on the aquatic environment. [Means for solving the problem]

[0009] The present invention provides a further surprising development of current technology, particularly with regard to its novel functionalization for optimizing and fine-tuning alumina for improved adsorption of a wide range of poly- and perfluorinated alkyl substances (PFAS), and shows that the surface functionalization demonstrated here may be broadly applicable for the remediation of PFAS contamination in water supplies.

[0010] A first aspect of the present invention provides a composition for removing a target substance from a fluid stream, comprising: a support material comprising alumina; A sorbent molecule comprising a core polymer; Including, The core polymer is covalently attached to a support material; A composition is provided in which the sorbent molecule further comprises one or more covalently attached sorbent groups.

[0011] Suitably, the core polymer is a linear or branched polymer.

[0012] A second aspect of the present invention is a composition for removing poly- and perfluorinated alkyl substances (PFAS) from an aqueous liquid, comprising: A particulate support material comprising bimodal alumina having mesoporous and macroporous inclusions, the bimodal alumina having a particle size of approximately 0.20 cm 3 / g or more; and a particulate support material having a BET pore volume in the mesoporous range. a sorbent molecule comprising a linear or branched core polymer selected from one or more of poly(allylamine), poly(methyl methacrylate), poly(vinyl alcohol), poly(vinylamine), poly(vinyl chloride), poly(ethyleneimine), poly(2-vinylpyridine), poly(3-vinylpyridine), and poly(4-vinylpyridine); Including, The core polymer is covalently attached to a support material; A composition is provided in which the sorbent molecule further comprises one or more covalently attached sorbent groups.

[0013] A third aspect provides a process for removing target substances from a fluid stream, preferably an aqueous feed stream, comprising contacting the feed stream with a composition as described herein.Target substances may include one or more PFAS.Typically, the aqueous feed stream is selected from polluted water, wastewater, groundwater, drinking water, seawater, and industrial and agricultural runoff.

[0014] In a fourth aspect, there is provided a process for removing a target substance from a fluid stream comprising contacting the fluid stream with a composition, a support material comprised of particulate alumina, and a sorbent molecule comprising a core polymer, the core polymer being covalently bonded to the support material, and the sorbent molecule further comprising one or more covalently bonded sorbent groups selected from one or more groups selected from substituted or unsubstituted C1-C12 alkyl groups, substituted or unsubstituted C2-C12 alkenyl groups, substituted or unsubstituted C2-C12 alkynyl groups, substituted or unsubstituted C1-C12 alkoxy groups, substituted or unsubstituted C1-C12 acyl groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic groups, heterocyclic groups, and hydrogen atoms.

[0015] In a fifth aspect, the compositions described herein are disposed in a filter, which may also be comprised of a bed or a packed column, and the fluid flow passes through or across the filter, bed or packed column. Preferably, the filter is for adsorbing one or more PFAS from a contaminated water source. The filter may be used in a point-of-use (POU) or point-of-entry (POE) water filtration system.

[0016] It is expressly intended that within the scope of the present disclosure, the various aspects, embodiments, examples and alternatives set out in the above paragraphs, claims and / or the following description and drawings, and in particular their individual features, may be obtained independently or in any combination, i.e. all embodiments and / or features of any embodiment may be combined in any way and / or combination, unless such features are incompatible. [Brief description of the drawings]

[0017] [Figure 1] A graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples is shown, where granular activated carbon (GAC), Resinex, and Purolite are comparisons of existing known sorbent materials. Alumina raw material is also tested as a comparison of an unfunctionalized support material (Alumina 1). Two alumina samples are functionalized with a core polymer, 25 KDa PEI, at two levels of surface activation (10-08 and 10-10), and both are tested after further modification to incorporate C8 acyl sorbent groups, respectively (10-12 and 10-13). [Diagram 2] 1 shows a graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples treated with octanoyl (C8 acyl) PEI substitution on a series of different alumina substrates. [Diagram 3] Figure 1 shows a graph of batch testing of the removal (% adsorption) of five different PFAS contaminants from water samples treated with granular activated carbon (GAC), Resinex and Amberlite ion exchange resins as comparators of existing known sorbent materials. Two different alumina substrate materials (Alumina 1 and Alumina 4) functionalized with different molecular weight core polymer PEI are also tested. [Figure 4] Figure 1 shows a graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples treated with alumina 1 functionalized with a 25 kDa PEI core polymer and then further modified by the addition of sorbent alkyl groups and quaternization of tertiary amines. [Diagram 5] Figure 3 shows a graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples treated with granular activated carbon (GAC), Resinex, and Purolite as comparators of existing known sorbent materials. An alumina substrate material (Alumina 1 in Figure 3) is functionalized with a core polymer, PEI 25 kDa (Al-PEI) as a comparator, and then further modified by the addition of sorbent alkyl groups of different lengths: C8 (acyl PEI substituted Al), C4 (butyl), C6 (hexyl), and C10 (decyl). [Figure 6] Figure 1 shows a graph of batch testing of the removal (% adsorption) of five different PFAS contaminants from water samples treated with granular activated carbon (GAC), Resinex, and Purolite, a comparison of existing known sorbent materials. Two different alumina substrate materials (Alumina 1 and Alumina 4) are functionalized with a core polymer, PEI 25 kDa, and then further modified by the addition of sorbent alkyl groups of different lengths. [Figure 7] 1 shows a graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples treated with existing known sorbent material comparisons: granular activated carbon (GAC), Resinex, and Amberlite. A Family 1 material, octanoyl PEI substituted alumina 2 (10-73b), according to one embodiment of the invention, is compared to a Family 3 material, octyl PEI substituted alumina 2 (24-07b), according to another embodiment of the invention. [Figure 8] 1 shows a graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples treated with granular activated carbon (GAC), Resinex, and Amberlite, which are comparisons of existing known sorbent materials. Four test compositions of embodiments of the present invention are also tested using a range of alumina substrates. [Figure 9-1] Figure 8 shows isotherm plots of the three best performing embodiments (28-4a-4c) of the small alumina sorbent media evaluated against PAC (powdered activated carbon) for six PFAS contaminants. [Figure 9-2] Figure 8 shows isotherm plots of the three best performing embodiments (28-4a-4c) of the small alumina sorbent media evaluated against PAC (powdered activated carbon) for six PFAS contaminants. [Figure 10] 1 shows a graph of pressure drop versus flow rate for 7 mm and 13 mm functionalized alumina depth membrane encapsulated adsorbent structure (MEAS) setups according to an embodiment of the present invention. [Figure 11] 1 shows a graph of the PFOA breakthrough curve in water for a 7 mm MEAS device. [Figure 12]Figure 1 shows the underwater PFAS GenX breakthrough curve for the 7mm MEAS device. [Figure 13] Breakthrough curves for (a) PFOA and (b) GenX are shown on a 13 mm MEAS device. [Figure 14] FIG. 1 shows a graph of batch testing of the removal (% adsorption) of seven different water PFAS contaminants using alumina functionalized with hexyl-PEI using either bromohexane or iodohexane as the alkylating agent. [Figure 15] (a) shows a graph of Hg porosimetry data for three different granular alumina materials before functionalization with sorbent molecules, and (b) shows a graph of batch testing of the removal (% adsorption) of five different aqueous PFAS contaminants using the same three granular aluminas that have been functionalized with hexyl-PEI. [Figure 16] 1 shows a graph of Hg porosimetry data for four different powdered alumina materials, Alumina 8 and Alumina AC. [Figure 17] FIG. 16 shows a graph of batch testing of removal (% adsorption) of four different PFAS contaminants in water using the same four powdered aluminas as in FIG. 16, but functionalized with hexyl-PEI, but showing the effect of pore size. [Figure 18] Figure 1 shows a graph of batch testing of removal (% adsorption) of seven different PFAS contaminants in water using four hexyl-PEI functionalized spherical aluminas (S-1 to S-4). [Figure 19] 1 shows a graph of batch testing of removal (% adsorption) of seven different water PFAS contaminants using alumina functionalized with hexyl-PEI with two different molecular weights of PEI. [Figure 20] 1 shows a graph of batch testing of removal (% adsorption) of five different PFAS contaminants from water samples treated with comparisons of existing known sorbent materials: granular activated carbon (GAC), Resinex, and Amberlite. Four test compositions of embodiments of the invention using alkyl-functionalized linear PEI were also tested versus alkyl-functionalized branched PEI using an Alumina 8 substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Unless otherwise indicated, the practice of the present invention will employ conventional techniques of chemistry, materials science, and process engineering, which are within the capabilities of a person skilled in the art.

[0019] Before describing the present invention, some definitions are provided to aid in the understanding of the present invention. All references cited herein are incorporated by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0020] As used herein, the term "comprising" means that any recited elements are necessarily included, and may optionally include other elements as well. "Consisting essentially of" means that any recited elements are necessarily included, excluding elements that would materially affect the basic and novel characteristics of the recited elements, and may optionally include other elements. "Consisting of" means that all elements other than those recited are excluded. Embodiments defined by each of these terms are within the scope of the present invention.

[0021] The term "target" or "target material" as used herein refers to a substance or compound that is desired to be removed or isolated from a fluid. Target materials may be dissolved (i.e., solute), suspended, emulsified, dispersed or otherwise carried in a fluid, and thus may be soluble, partially soluble or insoluble in the fluid. As discussed below, target materials may include contaminants and / or valuable materials that are desired to be removed and possibly recovered from the target fluid.

[0022] Target materials contemplated herein may include "contaminants" or "pollutants." In the context of the present invention, "contaminants" are intended to encompass materials that may be harmful to human or animal health or the environment. As such, derived terms are defined accordingly, for example, a contaminated fluid is a fluid that contains contaminants. Typically, the contaminant comprises one or more per- and polyfluoroalkyl substances (PFAS), typically one or more perfluorocarbons, optionally selected from perfluorinated anionic surfactant compounds, such as one or more selected from the group consisting of perfluoropentanoic acid (PFPeA), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHS), perfluorohexanoic acid (PFHA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), 6:2 fluorotelomer sulfonic acid (6:2FTSA), and hexafluoropropylene oxide dimer acid (HFPO-DA, also known as GenX chemicals and having the chemical name 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid). In some embodiments, the contaminant comprises an organic compound, optionally a pharmaceutical or pesticide molecule, including one or more selected from the group consisting of diclofenac, erythromycin, estrogen, oxadiazon, and thiamethoxam. The contaminant, in some embodiments, may be a metal or metalloid ion, optionally selected from copper, iron, lead, mercury, chromate, or arsenate.

[0023] The term "fluid stream" or "feed stream" refers to a flowable material, preferably a liquid, such as an aqueous liquid in which a target material is dissolved, suspended, emulsified, dispersed or otherwise carried. Typically, the liquid contains water or is primarily water-based and may be in the form of polluted water, wastewater, drinking water, seawater and / or industrial or agricultural runoff.

[0024] The terms "sorption", "sorb", "sorbent" and derivatives as used herein refer to the removal of a target substance, such as a contaminant, from a fluid stream by association of said target substance with the modified support material as described. Sorption by a material can occur by any means, such as adsorption to the surface of the material, which can be by the formation of a chemical interaction between the target substance and the support material, such as electrostatic attraction, hydrophobic interactions, covalent bond formation, ligation, chelation, van der Waals forces, hydrogen bonds, etc. "Sorption" can also refer to the absorption of a target substance into a material. The target substance can become physically trapped in intermolecular spaces, pores or other voids within the material. In particular, sorption can be adsorption resulting from the formation of a chemical interaction between the target substance molecules and the sorbent molecules, as defined herein, used to modify the sorbent material. Such chemical interaction results in the sequestration of the target substance from the fluid stream into the sorbent material. The use of the term "adsorption" or its derivatives herein is not intended to be bound by any theoretical limitations, but rather is intended to include sorption by other means as defined above, unless specifically indicated otherwise.

[0025] The term "sorbent material" as defined herein means a support or substrate material that further comprises sorbent molecules attached or bound thereto. The sorbent material is suitable for contacting a fluid stream containing a target substance, such as a contaminant that may be a PFAS, thereby adsorbing or otherwise capturing and isolating the target substance from the fluid stream onto the sorbent material. Suitably, the sorbent material is disposed in a filter / clarifier and / or bed or packed column (e.g., including multiple stacked filters) and the fluid stream passes through or across the filter, bed or packed column. The sorbent material may be disposed in a mixed bed in combination with another sorbent material, such as granular activated carbon or ion exchange resin. In one embodiment, the sorbent material is included in a prepared component, such as a filter cartridge, such that the sorbent material used can be conveniently contained and also replaced or replenished with new or regenerated sorbent material as needed. Alternatively, the sorbent material may be added to the fluid as a dispersion. The sorbent material may be particulate, i.e. in the form of granules, flakes, beads, pellets or tablets. The sorbent material may be a powder, which may advantageously provide a larger contact surface area. The sorbent material may be incorporated into a membrane or membrane filter. Membranes made of alumina substrate materials may also be directly functionalized as described herein. In particular, the membrane or membrane product may be used to make a filter. The advantage of such a filter is that it may be made with a specific thickness and large surface area, while also ensuring the passage of the fluid when properly installed in the fluid flow path with minimal flow rate reduction. Furthermore, the filter may combine the functionality of the present invention and particle (size exclusion) removal capabilities. The filter bed or column may be backwashed from time to time to remove the buildup of blockages such as organic matter or limescale that reduce flow rate.

[0026] In one embodiment, the sorbent material is in particulate, preferably granular, form, with the particles or granules having an average diameter size (as measured by the maximum diameter of the particle) greater than about 0.01 mm, preferably greater than about 0.1 mm, typically less than about 5 mm, less than approximately 3 mm, optionally less than about 1 mm, or even less than approximately 700 μm. In one embodiment of the invention, the granules have a d50 average particle size of approximately 600 μm diameter.

[0027] In a further embodiment, the sorbent material is in particulate, preferably powder form, with the particles having an average diameter size (as measured by the maximum diameter of the particle) greater than about 0.1 μm, preferably greater than about 1 μm, optionally greater than 50 μm, typically less than about 300 μm. Typically, powdered alumina suitable for use in embodiments of the invention has a d50 average particle size of approximately 100 μm, optionally with the majority of the particles within the powder being greater than approximately 70 μm and less than approximately 300 μm in diameter. Powdered alumina may include powders having spherical particles.

[0028] In a further embodiment, the sorbent material is a particulate composition, preferably in the form of a spheroid or sphere, with the average diameter size of the spheroids (as measured by the maximum diameter of the particle) being greater than about 0.5 mm, preferably greater than about 1 mm and up to approximately 5 mm in size.

[0029] In one embodiment of the present invention, a composition for removing target substances and / or contaminants from a fluid stream is provided. The composition includes a sorbent material that includes a support material covalently bonded to target substance sorbent molecules. The support material has a high surface area to volume ratio, providing an efficient support for molecules that can act as sorbents for the target substances. The granular sorbent particles are designed to be arranged in a standard packed bed as a sorbent medium for wastewater treatment. The granules have some porosity, but are hard, durable and resistant to degradation. Larger granular sorbent media are also suitable for large-scale engineering applications (e.g., water purification in industrial or municipal facilities). Meanwhile, smaller particle sizes provide faster capture rates that allow for the creation of broad-spectrum target substance removal products for point-of-use (POU) and / or point-of-entry (POE) markets.

[0030] According to embodiments of the invention, the sorbent material may be directly integrated into a POU device, such as a cartridge-style filter, or may be adapted by third-party technology to be encapsulated in a sandwich membrane (e.g., a functionalized alumina bed between porous metal foil membranes) and subsequently configured as a POU device. A typical POU device design should be suitable for connection to a typical domestic faucet / tap or water supply line under a sink. The POU device and its components must withstand inlet pressures of up to 6 bar (87 psi) without leakage or structural damage. This pressure is the upper limit of pressures found in most domestic environments. Faucets / tap have a variety of supply pressures, so the POU device must function at inlet pressures as low as 1.4 bar (20 psi). Typical devices specify an inlet pressure range of 1.4 bar to 5.5 bar (80 psi), with some specified up to 6.8 bar (99 psi). The minimum acceptable flow rate for most consumers is approximately 2 L / min, although some devices can handle up to 3-4 L / min. Currently available products almost all operate with a 6 month life span (i.e., replacement twice a year). Given the unexpectedly high PFAS capacity of the compositions of the present invention, it is expected that a product life span of 6 to 12 months is easily achievable. To last 12 months, nearly 4400 L of water (approximately 1200 US gallons) must be treated, so a device is needed that demonstrates adequate treatment of 5280 L of water (20% more than capacity) before PFAS breakthrough according to NSF-53 certification testing. In a specific embodiment of the present invention, the POU device can be connected between an existing conventional water purification cartridge (not intended to remove PFAS) and a water faucet / tap. In this configuration, the POU device can provide an indication of when replacement is required, for example, based on the time or volume of flow through the device or both. At this point, the user can replace the cartridge containing the compositions of the present invention without requiring removal of any plumbing connections. The used cartridge can be regenerated according to the methods described herein.

[0031] In POE applications where water enters a building and the system continuously treats the water throughout the building's water supply, the sorbent material may be contained within a fiberglass reinforced plastic (FRP) cylindrical tank or cylinder. The amount of sorbent material may be designed for use within a prefabricated FRP cylinder configuration, which typically allows for a volume of approximately 10-20 liters of material to be held, allowing for a useful life of more than one year of normal domestic use before the sorbent material requires replacement or regeneration. A typical POE system may include multiple water treatment cylinders, with the sorbent material being included as a subcomponent within all of the cylinders or as a dedicated component within one of the multiple cylinders.

[0032] As used herein, the term "alumina" refers to aluminum oxide / hydroxide in various mineral forms. The term alumina includes, for example, corundum (Al2O3), boehmite (γ-AlO(OH)), diaspore (α-AlO(OH)), and gibbsite (Al(OH)3) (e.g., bayerite, doylite, and nordstrandite), and combinations thereof. The term alumina also includes aluminum oxide / hydroxide in various phases and polymorphic forms, such as gamma (γ) alumina, alpha (α) alumina, theta (θ) alumina, etc.

[0033] The sorbent composition of the present invention comprises a solid alumina support having a plurality of pores, i.e. cavities, channels or interstices whose depth is greater than their width. The pores are typically defined by a pore width / size / diameter, which is taken to represent the distance between two opposing walls of the pore (e.g., the diameter of a cylindrical pore or the width of a slit-like pore). Alumina, like most porous materials, can be classified as having micro-, meso- or macropores. Mesoporous materials are characterized by IUPAC as having a predominance of pores with widths in the range of 2-50 nm (Roquerol et al. (1994) Pure&Appl.Chem.66(8):1739-1758).

[0034] In an embodiment of the invention, the alumina support material is composed of mesoporous alumina with a majority of the pores having a diameter greater than 2 nm, preferably greater than 3 nm, typically greater than 4 nm, and optionally greater than 10 nm. By "majority" it is meant that more than 50%, typically more than 60%, 70%, 80%, and optionally more than 90% of the porous volume falls within the defined mesoporosity range.

[0035] In a specific embodiment of the invention, the alumina support material is composed of alumina with a bimodal porosity structure, with some of the porosity falling within the mesoporosity range and some falling within the macroporosity range. Pores with a diameter of more than about 50 nm are typically referred to as macropores. In an embodiment of the invention, alumina with mesoporosity as defined above and also with a higher proportion of macropores in the range of about 100 nm to about 20 μm, preferably about 0.5 μm to about 15 μm, and optionally about 1 μm to about 10 μm, is considered to exhibit advantageous sorption properties. Thus, in a specific embodiment of the invention, a bimodal alumina support material is provided, with the majority of the porosity falling within a first distribution of pores with diameters in the mesoporosity range of about 2 nm to about 50 nm and a second distribution of pores with diameters in the microporosity range of about 1 μm to about 10 μm. Surprisingly, it has been found that such bimodal aluminas provide an advantageous balance between sorption properties when functionalized, structural resilience, and optimal flow rates of liquids through beds composed of alumina particles. It will be appreciated that the present invention is not limited to bimodal aluminas, but may also include multimodal aluminas having a porosity range that falls within a combination of the mesoporous and macroporous ranges.

[0036] In a specific embodiment of the invention, the alumina has a granular particle size range of approximately 300-3000 μm for the larger so-called particles, and a particle size range of approximately 0.1-300 μm for the smaller so-called particles, e.g., powder. As previously described, the smaller particles show utility as components in the design and manufacture of POU filtration devices, while the larger particles may be utilized in packed beds for POE, industrial or city-scale purification plants. In a specific embodiment of the invention, the filtration device may include any one combination of sorbent materials. Surface area and porosity may be determined by a combination of gas adsorption-desorption techniques, such as the Brunauer-Emmett-Teller (BET) technique and mercury intrusion porosimetry, or typically porosimetry. BET is a theory of gas adsorption on solid surfaces, essentially a further development of the Langmuir theory to include multi-layer formation. Mercury (Hg) intrusion is a physical technique that evaluates pore size / volume via interpenetration of materials by liquid Hg.

[0037] The sorbent material is bound to a sorbent molecule comprised of a polymer core, preferably a linear or branched polymer. The core polymer may be selected from one or more of the group consisting of poly(allylamine), poly(methyl methacrylate), poly(vinyl alcohol), poly(vinylamine), poly(vinyl chloride), poly(ethyleneimine), poly(2-vinylpyridine), poly(3-vinylpyridine), and poly(4-vinylpyridine).

[0038] In a specific embodiment of the invention, the core polymer comprises a linear or branched polyamine that serves as the structural core of the sorbent molecule. A polyamine is a compound that contains three or more amino groups. In an embodiment of the invention, the sorbent molecule comprises a polyamine core having a molecular weight of more than 500 Daltons (Da). In a specific embodiment of the invention, the polyamine core is composed of a polymer having a weight average molecular weight of 1 kDa, 2 kDa, 3 kDa, 5 kDa, 8 kDa, 10 kDa, 12 kDa, 15 kDa, 20 kDa, 25 kDa, 30 kDa, 40 kDa, 50 kDa, 75 kDa, 100 kDa, 250 kDa, 500 kDa, 750 kDa, 1000 kDa or more. In a specific embodiment, the polyamine core has a weight average molecular weight of approximately 25 kDa or more. Highly branched polyamine polymers, sometimes referred to as "dendrimers," contain multiple primary amino groups on each polymer molecule and may be utilized in specific embodiments. The polyamines utilized in the sorbent molecules of the present invention contain at least one terminal amine.

[0039] In one embodiment of the invention, the polyamine core comprises polyethylenimine (PEI), also known as polyazalidinium or poly(iminoethylene). Suitably, the PEI is linear or branched PEI. Optionally, the core polymer comprises poly(ethylenimine) having a weight average molecular weight of approximately 25 kDa.

[0040] Scheme 1 below shows the initial synthesis procedure utilized to surface functionalize the alumina substrate to allow for the attachment of the core polymer according to an embodiment of the present invention. The first step is the functionalization of the alumina surface. The initial functionalization of the alumina surface is not limited to the use of organosilanes. Those skilled in the art will recognize that oxide surfaces react readily with carbonyl-containing compounds (aldehydes, carboxylic acids) and phosphorus-containing compounds (e.g., phosphonic acids, esters, etc.). Those skilled in the art will also recognize that the density of hydroxyl groups on the surface of the substrate can be increased by treating the surface with compounds such as bases, acids, and oxidizing agent mixtures (e.g., H2O2 and HCl or HNO3). [ka]

[0041] R1, R2, and R3 can be the same or different, and preferably R1, R2, and R3 can be one or more groups selected from substituted or unsubstituted C1-C12 alkyl groups, substituted or unsubstituted C2-C12 alkenyl groups, substituted or unsubstituted C2-C12 alkynyl groups, substituted or unsubstituted C1-C12 alkoxy groups, substituted or unsubstituted C1-C12 acyl groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic groups, heterocyclic groups, and hydrogen atoms. In a specific embodiment, R1 is a C1-C12 acyl group, R2 is an alkyl group or a hydrogen atom, and R3 is absent. Since the polymers are of various sizes, the above scheme is shown as defined within the square brackets as an approximation. It will be appreciated that although the above scheme depicts a branched polymer, it is also applicable for use with linear polymers, such as linear PEI.

[0042] Step 1: Organosilanes are suitable reagents for functionalizing alumina surfaces because they are structurally diverse, readily available on a large scale, and known to react with a wide range of oxide-containing surfaces. Functionalized organosilanes are typically selected such that, once attached to the inorganic oxide surface, the appended functional group serves as a point for further synthetic modification (described in step 2 below). Reactive functional groups may be selected from, but are not limited to, chlorides, bromides, iodides, protected alcohol groups, esters, epoxides, acrylamides, alkenes, and alkynes. It will be appreciated that alternative chemistries for functionalizing alumina surfaces may also be employed and are known to those skilled in the art.

[0043] The reactive functional group, in this example the chloride, can subsequently be displaced by a wide range of nucleophiles. Nucleophiles such as amines or alcohols react readily with alkyl chlorides via SN2 type nucleophilic displacement to form carbon-nitrogen or carbon-oxygen bonds. It will be appreciated that it is possible to select organosilanes with other reactive functional groups (see list above). In one embodiment, 2-propanol is the solvent of choice for the reaction, although the reaction can be carried out in other alcohol-containing solvents or in hexane, toluene or even water.

[0044] Step 2: The silane-functionalized alumina substrate is suitably reacted with a core polymer (e.g., as defined within the brackets in the scheme shown above) containing one or more functional groups that can be further derivatized by the addition of at least one sorbent group. Such core polymers can be selected from the group of poly(allylamine), poly(methyl methacrylate), poly(vinyl alcohol), poly(vinyl amine), poly(vinyl chloride), poly(ethyleneimine), poly(2-vinylpyridine), poly(3-vinylpyridine) and poly(4-vinylpyridine). Core polymers containing nitrogen atoms are particularly suitable because they can be further derivatized after being bonded to the silane-functionalized alumina material. Suitable weight average molecular weight ranges for the polymers are PEI (0.8-1000 kDa), PVP (approximately 60-160 kDa) and PVC (approximately 48 kDa).

[0045] Step 3: The alumina intermediate containing the attached core polymer may be further derivatized to introduce sorbent groups to improve binding specificity to certain target substances present in the fluid feed stream. If the core polymer selected in step 2 is a polyamine, the polyamine-alumina intermediate may be reacted with compounds such as acid chlorides (including but not limited to alkanoyl chlorides) to provide amide functional groups, or with organic halides to introduce hydrocarbon groups of various lengths or sizes (e.g., alkyl, alkenyl, alkynyl, cycloalkyl or aryl groups). The amine nitrogen atom is versatile in the sense that it may be derivatized with a wide range of reagents. Thus, it is possible to derivatize the amine nitrogen center via reaction with other reagents, for example, reductive amination with aldehydes to provide alkyl chains, condensation with carboxylic acids to give amides, Michael addition with double bond-containing compounds, addition of alkynes or alkenes, amidation reactions with esters (or other carbonyl-containing compounds), reaction with strained ring systems such as epoxides, aziridines, or reaction with organic halides such as alkyl, benzyl, aryl, etc. Thus, the addition of various sorbent groups can be tailored to the particular target material being removed from the fluid stream.

[0046] It is a significant advantage that the sorbent compositions of the present invention have unique sorption properties that can be tailored to the specific requirements of the sorbent material. It is therefore an advantage of the present invention that the sorbent material can be easily optimized to target specific substances and / or contaminants in a fluid stream by chemical modification of the sorbent molecule. For example, sorption properties can be optimized for specific target substances through the combinatorial selection of alumina properties (e.g., pore size), core polymer and / or sorbent groups. In this way, the physical properties of the support material show synergy with the chemistry of the sorbent molecule to provide unexpected properties in terms of target-specific sorption. This is most evident in the embodiments of the present invention described in detail below, where certain compositions show improved performance in removing a range of PFAS from water compared to industry standard activated carbon compositions. According to specific embodiments of the present invention, the primary treatment targets in water feeds are poly- or perfluorinated surfactants such as PFOA, PFOS, PFPeA, PFHA, PFHS, PFBA, PFBS, 6:2FTSA, HFPO-DA, etc.

[0047] It is also envisioned that treatment of effluents, wastewater or other water feeds to remove other target substances, contaminants or valuable materials (including precious or rare earth metals, such as those present in wastewater from mining, refining or manufacturing processes), or treatment of other fluids such as biological media, organic solvents, oils, or removal of impurities from liquid product streams is possible. In addition, the sorbent material according to the present invention may be used as a sorbent for removing target substances from gaseous feed streams such as carbon dioxide in direct air capture (DAC) units.

[0048] Unlike other sorbents thus arranged for organic pollutants, the sorbent material can be effectively regenerated in situ by a solvent wash step. The solvent wash may include an aqueous salt wash, an acid wash, a base wash or a combination, for example a salt and an acid wash. The regeneration solution may additionally or alternatively include a non-aqueous polar solvent such as acetone, or an alcohol such as ethanol, methanol, isopropanol may be used. Suitably, if an aqueous wash is used, the wash may include a liquid having a pH greater than 9 or alternatively less than 5. Optionally, the wash solution includes an aqueous ammonium hydroxide, ammonium chloride, ammonium sulfate, potassium hydroxide, sodium bicarbonate or sodium hydroxide solution. In some embodiments, the wash liquid has a pH greater than 8, preferably greater than 9 or greater than 10. If an acid wash is used, it is preferably selected from inorganic acids including hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or alternatively an organic acid preferably selected from acetic acid, hexanoic acid, ethanedioic acid or citric acid. The salt is preferably selected from sodium, potassium or magnesium salts with chloride, sulfate or phosphate counterions. The possibility of regeneration is particularly advantageous in the sense that it allows the removal of the target substances for recycling, recovery or safe disposal and allows the reuse of the sorbent material, thus further reducing the costs and the generation of waste in the form of used sorbent material.

[0049] The regeneration process preferably involves removing the sorbent material from the fluid stream and contacting it with a wash solvent as described. In an alternative embodiment, the regeneration process involves exchanging the fluid stream with a solvent wash for a period of time to effect regeneration.

[0050] Without wishing to be bound by theory, it is believed that the adsorption of target substances to the compositions described herein is primarily the result of non-covalent interactions, such as electrostatic interactions with the polyamine core, combined with hydrophobic-hydrophobic interactions with covalently attached hydrophobic groups. In the regenerating solvent wash step, interactions with polar groups, such as anions, during washing replace electrostatic interactions with the anionic target substances, releasing the target substances during washing. The electrostatic interactions with the adsorbed target compounds can be further reduced by increasing or decreasing the pH to change the protonation state of the polyamine core. The presence of other ions, such as ammonium, can improve the solubility of the adsorbed target compounds, further increasing their removal during the regenerating solvent wash step.

[0051] Another notable advantage of the present system is its low cost and ease of production. The production of granules or other forms of sorbent material using a relatively low-cost core polymer and very low-cost support material (e.g., alumina) allows for cost-effective production of the material on a large scale (~1000 kg / batch) and enables implementation in high-volume wastewater applications (multiple megaliters / day flow rates). In addition, the reactions involved in binding the sorbent substrate with the target substance sorbent molecules can be carried out economically on a large scale, often at relatively low temperatures (e.g., less than 100°C) and atmospheric pressure.

[0052] The present invention is further illustrated by the following non-limiting examples. EXAMPLES

[0053] Physical properties of alumina support materials The physical properties of the alumina feedstock substrates procured and selected for functionalization are shown in Table 1 below.

[0054] [Table 1] TIFF2025507589000004.tif176169

[0055] The BET method is applicable to Type II (disperse, non-porous or macroporous solids) and Type IV (mesoporous solids, pore diameter 2 nm to 50 nm) adsorption isotherms. BET and complete adsorption isotherms are commonly used to measure surface area, total pore volume, mesopore volume, area and distribution, and micropore distribution. Pores with a width greater than about 50 nm (0.05 pm) are called macropores, pores with a width between 2 nm and 50 nm are called mesopores, and pores with a width of about 2 nm or less are called micropores.

[0056] For materials with larger pore sizes, mercury intrusion porosimetry is recommended, covering an approximate range of 3 nm to 600 μm (mesoporous to macroporous materials), but larger sizes depend on the nature of the sample. The results provide the porosity, pore size, pore area and pore volume. An alternative method for the determination of the total pore volume of a sample is by a combination of mercury pycnometry (bulk density measurement) and helium pycnometry (absolute density measurement).

[0057] Materials with a high proportion of mesopores (2-50 nm) are desired: the pores should be large enough to accommodate the sorbent molecules used in the functionalization derivatization step, and remain large enough to capture the target pollutant molecules (e.g., PFAS molecules) with high capacity after functionalization.

[0058] The large alumina particle class is broadly defined as 155-330m 2 / g and has a surface area of ​​0.22 to 0.41 cm 3 / g and an average pore size of 3-5 nm. The smaller class of alumina particles can be classified as having a pore volume of 136-280 m 2 Surface area / g, 0.47-0.76 cm 3 / g and a larger average pore size of 7-20 nm.

[0059] Example 1 - Functionalization and derivatization of large granular alumina particles Using steps 1-3 (see Scheme 1 above), alumina raw material: (1) Acyl-derivatized PEI-substituted alumina (2) Quaternary acyl PEI-substituted alumina (3) Alkyl-substituted PEI-substituted alumina Three families were illustrated. [ka]

[0060] Family 1 Test (Large Granular Alumina): Batch test data for the material family is shown in Figure 1. Alumina substrate characterization data is presented in Table 1 (above) and functionalized material characterization data is presented in Table 2 (below). As shown in Figure 1, the alumina feedstock has moderate PFAS removal for PFOS, which can be related to the mesoporous structure of the alumina feedstock. The batch test data in Figure 1 below demonstrates that functionalization of the alumina substrate results in improved PFAS removal compared to raw unfunctionalized alumina substrate and intermediate material (PEI-alumina). The material in Figure 1 was prepared using 3-chloropropyltrimethoxysilane activation of alumina (Step 1, Scheme 1), 25 kDa PEI (Step 2, Scheme 1) and functionalization with octanoyl chloride (Step 3, Scheme 1).

[0061] Within Material Family 1, different alumina substrates were tested (Alumina 1, Alumina 4, and Alumina 6) to demonstrate the applicability of the chemistry to several different alumina substrates. Batch test data is shown in Figure 2. Characterization of the unfunctionalized alumina substrate is given in Table 1 (above) and product characterization is shown in Table 2 (below).

[0062] PFAS removal performance was observed to follow the following trend for alumina cores: 10-61b (alumina 1)>10-63b (alumina 4)>>10-62b (alumina 6). The poor PFAS removal performance of 10-62b (alumina 6 core) compared to 10-61b (alumina 1 core) and 10-63b (alumina 4 core) (Figure 2) is likely related to the lower functionalization level as determined by C and N elemental analysis (the moiety capable of trapping PFAS) in alumina 6-based materials (see Table 2).

[0063] The three large granular alumina raw materials have similar surface areas (316–331 m 2 / g, but the pore volume and average BJH pore size tend to be: Alumina 1 (0.40 cm 3 / g, 5 nm)>Alumina 4 (0.38 cm 3 / g, 5 nm)>>Alumina 6 (0.22 cm 3 / g, 3 nm). The optimized performance comes from the complementary matching of the polymer and functionalization with the pore size and pore volume of the alumina substrate.

[0064] The effect of the molecular weight of the PEI core polymer (Step 2, Scheme 1) was investigated with two major alumina feedstocks within Family 1 (Alumina 1 and Alumina 4). Batch test data are shown in Figure 3. The data show that the PFAS removal performance with each alumina substrate tested improved gradually with increasing molecular weight of PEI (up to a weight average MW of 25 kDa), with the effect becoming more pronounced against short-chain PFAS targets. Furthermore, the performance of Alumina 1 was better than that of Alumina 4.

[0065] Family 2 and 3 Testing (Large Granular Alumina): The second and third material families created took the Family 1 material and introduced additional levels of functionalization via alkylation and quaternization reactions of the sorbent molecule. The motivation for implementing this chemistry was two-fold: (1) to introduce more alkyl chains, and (2) to introduce quaternary nitrogen centers within the core polymer. Both of these additional steps result in significant and unexpected improvements in PFAS removal compared to a control material functionalized with only octanoyl side chains. Batch testing data is presented in Figure 4. Material characterization data is presented in Table 2 below.

[0066] Results show that further improvements in short-chain PFAS removal are seen by reacting 10-61b (octanoyl-substituted PEI-alumina 1) with either iodomethane or iodobutane to give 10-64b and 10-65b, respectively. To demonstrate the scalability of these results, 21-04b (same chemistry as 10-61b) was prepared at a 1.2 kg scale and further reacted with iodomethane (21-05b) or iodobutane (21-06b). Thus, alkylation of the octanoyl-substituted PEI-alumina material (10-61b) results in increased removal of short-chain PFAS. Reaction of the octanoyl-substituted PEI-alumina material (10-61b) with iodobutane (10-65b) also results in improved short-chain PFAS removal compared to reaction of the acyl-substituted PEI-alumina material with iodomethane (10-64b).

[0067] Given the results from Family 2 materials, a key hypothesis was whether acylation (via reaction of PEI-alumina with octanoyl chloride) would provide effective PFAS removal. It has already been shown that simple alkylation with an excess of alkyl halide compounds produces materials with excellent overall PFAS removal properties. The effect of alkylating reagent chain length was first examined with C4-C10 within the butyl, hexyl, and decyl families examined with Alumina 1. Batch test data is shown in Figure 5 and characterization data is presented in Table 2 (below). The effect of alkylating reagent chain length was also examined with Alumina 4. Batch test data is shown in Figure 6 and compared to data from Alumina 1 (where applicable). Characterization data is given in Table 2 below.

[0068] The results of these experiments show that the best performing materials from the two families (Alumina 1 and Alumina 4) based on PEI cores show that the hexyl chain length is optimal for the removal of the specific PFASs tested. The results also show that the impact of both the achievable chain length and the degree of functionalization on the porous substrate and their impact on PFAS removal performance is highly dependent on the porosity (pore volume and pore size) of the starting substrate. It will be recognized that for other PFASs or target substances tested, the selection of the optimal sorbent group may be different. Nevertheless, the results demonstrate the principles underlying the synergy between substrate material selection and sorbent molecule functionalization in improving the removal of the target substance.

[0069] Figure 7 compares the PFAS removal performance of octanoyl PEI substituted alumina 4 (10-73b) with octyl PEI substituted alumina 4 (24-07b). Both chemistries provide C8 side chains on the PEI core polymer backbone. Characterization data is provided in Table 2 below. The batch test data in Figure 7 shows that the 24-07b material has superior broad-spectrum short- and long-chain PFAS removal compared to 10-73b.

[0070] [Table 2]

[0071] Example 2 - Functionalization and derivatization of small granular alumina particles Three commercially available alumina sources (d50<100 microns) were selected for functionalization (see Table 1 above and Table 3 below). A comparative example of large granular alumina particles (Alumina 4) is given.

[0072] [Table 3]

[0073] Alumina raw feedstocks were surface functionalized using a three-step process developed for the large aluminas (Scheme 1) Family 3 (see above) and summarized below as Scheme 2. For the materials exemplified in this work (28-4a, 28-4b, 28-4c), iodohexane was utilized in the final functionalization step (Scheme 2, Step 3). However, it should be recognized that the scope of functionalization is not limited to iodohexane and other haloalkanes (C4-C12) may also be utilized, as exemplified for Alumina 1 and Alumina 4 (above). [ka]

[0074] Analytical data for the three fully functionalized alumina materials (28-4a, 28-4b, 28-4c) are shown below in Table 4. For reference, the best performing (by PFAS removal) larger particle size alumina 24-06b - with the same hexyl surface functionalization chemistry - is included.

[0075] [Table 4]

[0076] Please note the following: The smaller alumina feedstock compared to the larger alumina 4 substrate (Table 3) had significantly larger average pore size (7-20 nm vs. 5 nm) and pore volume (0.47-0.76 cm 3 / g vs 0.38cm 3 / g). There is substantially more functionalization on the surface of the smaller functionalized alumina adsorbent media compared to the larger ones, as judged by carbon and nitrogen content (see Table 4) and confirmed by FTIR analysis (not shown). The carbon to nitrogen ratio is greater in the smaller alumina adsorbent media compared to the larger ones (approximately 4-4.5:1 vs. 3:1), suggesting that the polyethyleneimine (PEI) backbone nitrogen atoms in the smaller adsorbent media may have a higher degree of alkylation. · When the alumina substrate is functionalized (Table 4), the percentage of pore volume reduction is greater in the smaller alumina adsorbent media than in the larger granular media (31-41% vs. 26%).

[0077] Elemental and porosity analysis confirm that the smaller alumina sorbent media have a higher degree of surface functionalization than the larger 24-06b material. There is a positive correlation between the functionalization level and pore diameter, which is in fact inversely related to the surface area as determined by BET. This was unexpected, since typically one would assume that surface area is the major contributing factor, but the data now show that the pore size of the substrate material is an important feature that contributes to the properties of the sorbent compositions of the present invention. Predominantly mesoporous substrate materials, especially those with average pore sizes greater than approximately 4 nm, are particularly suitable for PFAS removal from water.

[0078] The initial PFAS removal performance of the new smaller sorbent materials was characterized in 24-hour batch tests, as previously performed. Figure 8 shows the batch test data for the new compositions (28-4a, 28-4b, 28-4c) compared to 24-06b and the reference compositions GAC and conventional ion exchange resins (Amberlite and Resinex).

[0079] Isotherm Data Isotherm batch studies were performed to understand the removal capacity of the new sorbent media (28-4a, 28-4b, 28-4c). Representative plots are shown in Figure 9 for six different PFAS substances evaluated against powdered activated carbon (PAC).

[0080] Table 5 shows the comparative performance of the new materials compared to small particle activated carbon materials in terms of PFAS removal capacity.

[0081] [Table 5]

[0082] The best performing small alumina material in these tests was 28-4b, which can be related to the high functionalization level of the particle's surface.

[0083] Materials and Methods Silanization reaction (Step 1, Schemes 1 and 2). 50 g alumina was added to 2-propanol (150 mL) and 3-chloropropyltrimethoxysilane (1.4 mL). The suspension was stirred at 65° C. for 24 h using an overhead stirrer at ∼150 rpm. The material was then washed with 2-propanol (3×150 mL) and then dried under vacuum at 80° C. for 3 h. The material was then further dried under vacuum at 40° C.

[0084] The PEI reaction (Step 2, Schemes 1 and 2) was carried out on a 30 g scale. 30 g of the dried silanized product was added to a solution consisting of PEI (e.g., MW=25 kDa, 9 g) and DI water (150 mL). This was heated to 70° C. with stirring at ∼150 rpm for 24 h. 10 M NaOH (5×90 μL portions in total) was added at 30 min, 1.5 h, 2.5 h, 3.5 h, and 4.5 h. The material was then washed with water adjusted to pH 4 with HCl (2×150 mL), DI water (150 mL), 0.1 M aqueous potassium carbonate (2×150 mL), and DI water (2×150 mL), and then dried under vacuum at 40° C.

[0085] The acylation reaction (Step 3, Scheme 1) was carried out on a 40-80 g scale. The aminated product (40 g) was carefully added to octanoyl chloride (20.4 mL = 3 mmol / g PEI-substituted alumina) in anhydrous acetonitrile (120 mL). The suspension was stirred at 25 °C for 5 h. The material was carefully washed with 2-propanol (4 x 50 mL), then with DI water (4 x 50 mL) at 50 °C and finally with 0.1 M aqueous potassium carbonate (250 mL) at 50 °C for 1 h. The final product was filtered, washed with water (100 mL) and dried under vacuum at 40 °C overnight.

[0086] The alkylation reaction (Step 3, Schemes 1 and 2) was carried out on a 15 g scale. 15 g of the aminated product was added to a suspension consisting of potassium carbonate (14.9 g) and 2-propanol (45 mL). 1-Iodohexane (13.28 mL) was added and the suspension was stirred at 80° C. overnight. The material was then washed at 50° C. with 2-propanol (4×50 mL), 0.1 M aqueous potassium carbonate (2×50 mL) and DI water (2×50 mL). The final product was dried under vacuum at 40° C. overnight.

[0087] To purify the functionalized material, the final product was split into two 50 mL Falcon tubes. 45 mL DI water was added to each and shaken for 30 minutes, then centrifuged. The water was then removed and analyzed for TOC, TN and aluminum content. An additional 45 mL of DI water was then added to each Falcon and the process was repeated until a total of eight washes had been performed.

[0088] Example 3 – Membrane-encapsulated filtration devices for point-of-use (POU) applications Following successful testing of Examples 1 and 2 treating PFAS-contaminated water, the membrane encapsulated sorbent structure (MEAS) filled with functionalized alumina described in the present embodiments was tested with additional PFAS species specified in the interim version of the updated NSF-53 industry standard protocol further covering GenX. The MEAS included a functionalized alumina composition positioned between porous metal foil support membranes.

[0089] Desired parameters for a typical POU device are shown in Table 6. These parameters are indicative of the requirements for a typical under-sink cartridge, such as for home use.

[0090] [Table 6]

[0091] method Operation parameters Two MEAS test cells with alumina powder bed depths of 7 mm and 13 mm were tested simultaneously. The alumina powders filled in these cells followed the same functionalization procedure but were from different production batches. The 7 mm cell contained 20.1 g of powder and the 13 mm cell contained 35.4 g of powder.

[0092] Water was supplied at a flow rate of 150 mL / min using a peristaltic pump. The flow rate was monitored periodically throughout the experiment and maintained at 140-160 mL / min. The system was operated for approximately 8 hours per day and was turned off overnight.

[0093] [Table 7]

[0094] This flux (2440L / h m 2 A POU device capable of handling 2 L / min at 500 cm 2 of membrane surface area. Keeping constant the operating parameters tested in the test device, the required scale factor is 13.3. Using this scale factor, the volume of water treated by test cells 1 and 2 can be converted to an equivalent volume of water treated by the full-scale device. Thus, the treatment of 200 L of water through the test device is equivalent to 2670 L in the full-scale device.

[0095] Water matrix and sampling The PFAS species used and their concentrations are presented in Table 8 below.

[0096] [Table 8]

[0097] Current NSF-53 protocols specify that the water for testing should come from a public water supply and that the specific characteristics shown in Table 9 should be maintained throughout.

[0098] [Table 9]

[0099] For purposes of initial testing, deionized water was used instead of London tap water. The concentrations of the ions added to the water are presented below in Table 10. This water meets NSF standards for pH and TOC. TOC was added as chlorinated tannic acid as specified by NSF protocols. Other ions were selected to represent the median concentrations of many common water matrix constituents. Note that the current NSF-53 does not specify an upper limit for GenX, but for purposes of this testing a recommended limit of 135 ppt is assumed.

[0100] [Table 10]

[0101] Sampling Method Samples were taken from the effluent line port at 2-hour intervals throughout the duration of the 70-hour experiment, with more frequent sampling during the first 2 hours of the experiment.

[0102] Samples were sent weekly for PFAS quantification by LC-MS. The detection limits for this technique range from 0.5 ppt to 2 ppt, depending on the PFAS species. The quantification limits range from 2 ppt to 7 ppt.

[0103] result Flow Control and Pressure Drop Prior to the start of the PFAS flow test, a graph of pressure drop versus flow rate was generated by varying the pump speed. The data is presented in Figure 10. The results are clearly linear, with the pressure drop being very similar despite the alumina powder depth being almost twice as deep in one test cell.

[0104] The PFAS test began with an inlet pressure of 0.2 bar and 0.325 bar for the 7 mm and 13 mm test cells, respectively. This pressure steadily increased over the test period. After 150 L of water had passed through the system, the pressure in both systems had risen to approximately 0.5 bar. After 300 L, the inlet pressure for both systems was 0.9 bar. At the end of the experiment, both systems had an inlet pressure of over 1.2 bar.

[0105] The increase in inlet pressure throughout the experiment was significant and approximately equal in both test cells. There was a visible brown deposit on the feed side of the membrane.

[0106] Although the increase in inlet pressure cannot be entirely attributed to the presence of tannic acid from this experiment alone, the coloration of the sediments suggests that tannic acid may be the cause.

[0107] PFAS removal performance of 7mm test cell After treating 396 L of water over 44 hours, the PFOA concentration in the effluent of the 7 mm cell only started to rise sharply from 5 ppt to 15 ppt (see Figure 11). When extrapolated to a full-scale POU device, this is equivalent to 5284 L of water. It is estimated that an average European uses almost 20 L per day in their kitchen (Richter, CP and Stamminger, R. (2012). Water consumption in the kitchen - A case study in four European countries. Water Resource Management). Therefore, it would be expected that a scaled-up version of the 7 mm cell could function reliably as a POU device for six months. This is fully compliant with current industry standards.

[0108] The concentration of GenX in the effluent of the 7mm cell was first detected at a concentration of 6.6 ppt after treating 306 L of water (34 hours, 4080 L in the POU device) (see FIG. 12). After this point, the concentration of GenX in the effluent of the 7mm cell gradually increased, reaching a peak of 62 ppt after treating 464 L (51.5 hours, 6184 L in the POU device). The final GenX concentration recorded was 50 ppt. The concentration of GenX never even exceeded half of the assumed limit of 135 ppt.

[0109] The concentration of PFOS in the effluent of the 7 mm cell increased sharply to 14 ppt after treating 414 L of water (46 h in the POU device). The concentration was then maintained between 12 ppt and 17 ppt for the remainder of the experiment, but never exceeded the 20 ppt limit.

[0110] PFHxS was first measured above the limit of quantification after treating 396 L of water (44 hours, 5284 L for the POU device). After that point, the concentration of PFHS increased from 4 ppt to 11 ppt, which is below the 30 ppt limit for PFHS.

[0111] PFHpA and PFNA were first detected after treating 396 L of water (44 hours in the POU device). PFHpA was maintained below its limit of quantification of 5 ppt, which is safe below its regulatory limit of 20 ppt. PFNA was maintained below its limit of quantification of 6 ppt, which is also its regulatory limit. For PFNA, the exact concentration cannot be calculated throughout the study, but the maximum peak area observed for PFNA throughout the experiment was approximately half of the peak area at 6 ppt on the standard line.

[0112] PFAS removal performance of 13mm test cell The PFOA concentration in the effluent of the 13 mm test cell remained well below the regulatory limit of 20 ppt throughout the duration of the experiment. The amount of PFOA in the effluent never exceeded the limit of quantification (LOQ) of 4 ppt during the experiment. GenX was first detected in the effluent of the 13 mm cell above the limit of detection (LOD) after treating 396 L of water (44 hours, 5284 L for the POU device), but below the LOQ. The concentration of GenX increased from 8 ppt to 27 ppt by the end of the experiment (69 hours) after treating 464 L of water (51.5 hours).

[0113] PFHpA and PFNA remained below detection limits throughout the entire experiment, except for a few single points early on. PFHxS was detected near detection limits beginning at 38 hours (342 L treatment). For the remainder of the experiment, the amount of PFHxS never exceeded the LOQ of 2 ppt. PFOS was observed at detection limits from 61.5 hours (554 L treatment). Treatment of this volume of water is equivalent to functioning for over a year when extrapolated to a full-scale POU under-sink device.

[0114] The breakthrough curves for PFOA and GenX are presented in Figure 13(a-b).

[0115] PFAS capacity From the breakthrough results of the 7mm cell, the capacity of the alumina sorbent powder can be estimated. The total amount of PFAS captured per PFAS species was calculated by evaluating the inlet and effluent PFAS concentrations for each PFAS species and multiplying the difference by the volume of water treated before breakthrough (554L). This was then divided by the amount of powder in the cell (20.1g) to determine the capacity. The results are presented in Table 11 below.

[0116] [Table 11]

[0117] conclusion PFAS adsorption testing was performed according to NSF-53 guidelines for additional PFAS contaminants (GenX, PFHpA, PFNA, and PFHxS) in Puraffinity media encapsulated within the MEAS device. Two cells with different bed depths of 7mm and 13mm were used in parallel testing. The two cells had contact times of 10 and 19 seconds, respectively, loadings of 20.1g and 35.4g of sorbent powdered alumina media, and flow rates of 150mL / min each.

[0118] Sampling after 44 hours in the 7 mm test cell showed a change in effluent concentrations from non-detectable to detectable limits for most of the PFAS. The largest visible concentration changes were seen for PFOA and PFOS, both of which increased from 5 ppt to 16 ppt, but remained below 20 ppt. In the second 13 mm bed depth cell, no PFAS limits were exceeded. PFOA concentrations in the effluent of the 13 mm cell remained well below the regulatory limit of 20 ppt for the duration of the experiment.

[0119] These studies demonstrate the feasibility of the technique at laboratory scale and show its utility across a broad range of PFASs.

[0120] Example 4 – Hexyl-PEI functionalized alumina with iodohexane and bromohexane 11 Alkylation with bromohexane (Step 3, Schemes 1 and 2) was carried out on a 15 g scale. 15 g of the aminated product was added to a suspension consisting of potassium carbonate (12.4 g) and 2-propanol (30 mL). 1-Bromohexane (25.35 mL) was added and the suspension was stirred at 80° C. overnight. The material was then washed at 50° C. with 2-propanol (4×50 mL) and DI water (10×50 mL). The final product was dried overnight under vacuum at 40° C. Table 12 shows the elemental analysis of the product compared to functionalized alumina with iodohexane (see Example 2).

[0121] [Table 12]

[0122] The PFAS removal performance of the alumina 11 sorbent material was characterized in a 24-hour batch test, as previously performed. Figure 14 shows the batch test data for the new composition.

[0123] Example 5 - Porosimetry analysis of granular alumina While the BET data for alumina sources 1, 4 and 11 appear very similar, i.e., have similar micro- and mesoporosity levels (see Table 1), the Hg porosimetry data reveals a major difference in the macroporosity of the three substrates. Aluminas 1 and 11 have macroporosity (pores approximately 3 μm diameter) that Alumina 4 does not. Surprisingly, this porosity, in addition to mesopores approximately 3-8 nm diameter, may result in increased levels of functionality of the alumina surface and therefore increased PFAS removal performance. Figure 15(a) shows the Hg porosimetry data for alumina sources 1, 4 and 11.

[0124] The presence of macroporosity is beneficial for performance, but it can also cause the mechanical stability of the material to be compromised, so the two factors must be effectively balanced depending on the desired end use case. The macroporosity level of Alumina 4 results in a material that is too physically weak for use in certain types of water treatment applications. However, the lower level of macroporosity of Alumina 11 compared to Alumina 4 produces a material that is adequately stable in the intended application, but also has improved PFAS removal performance compared to mesoporous only materials. Performance batch data for hexyl-PEI functionalized aluminas 1, 4, and 11 are shown in Figure 15(b). Elemental analysis data for hexyl-PEI functionalized aluminas 1, 4, and 11 are shown in Table 13.

[0125] [Table 13]

[0126] Example 6 – Porosimetry analysis of powdered alumina Analysis similar to that performed in Example 5 was repeated on powdered alumina materials based on Alumina 8 or closely related aluminas (referred to as Aluminas A-C) and revealed similar trends in terms of pore size (see FIG. 16) and PFAS performance (see FIG. 17). However, the pore size range was shifted to larger mesopores, now with a range of 18-40 nm, compared to the 3-8 nm range for granular alumina. Unlike the granular media, no initial performance increase was observed, rather performance decreased with increasing mesopore size (see FIG. 17). Elemental analysis data also broadly followed the same trend, with a decrease in %C content observed with increasing pore size.

[0127] [Table 14]

[0128] Example 7 – Testing of spherical alumina particles Another common form of alumina (in addition to powders and granules) is spherical particles, which are often used as catalyst supports, gas and liquid desiccants, and hydrocarbon adsorbents. This form of adsorbent has advantages in large-scale industrial applications due to the rather large particle size (mm range), which would result in a lower pressure drop of the fluid passing through the packed bed composed of the particles. A drawback of such substrates is their mechanical strength, which presents a challenge both during application and during the synthesis of functionalized spheres. Four different spherical alumina substrates, designated S-1 to S-4, from two different manufacturers were tested (for physical properties, see Table 15 below):

[0129] [Table 15]

[0130] S-1 and S-2 were functionalized using the standard procedure by alkylation with iodohexane (Step 3, Schemes 1 and 2), while S-3 and S-4 spheres were functionalized using the standard bromohexane procedure described previously.

[0131] The functionalization of the alumina spheres was found to be lower compared to the granules, which is believed to be due to attrition during the synthesis process, without wishing to be bound by theory. However, the S-4 spheres showed promising performance indicators which are believed to be due to the bimodal porosity profile of the spheres (with both meso- and macroporosity peaks) and overall higher porosity.

[0132] [Table 16]

[0133] The PFAS performance batch data for hexyl-PEI functionalized alumina spheres is shown in FIG.

[0134] Example 8 – Variation of molecular weight of PEI polymer Aluminas 1 and 4 functionalized with 0.8, 1.8 kDa and 25 kDa PEI were used to prepare and test preacylated products (see Example 1 and Figure 3).

[0135] In this example, a hexylated PEI product was made with 750 kDa PEI (same mass as in the normal synthesis) using alumina 11 and compared to a hexylated PEI with 25 kDa PEI. The performance PFAS batch data for the larger 750 kDa PEI was found to be within error of the standard product made with 25 kDa hexyl-PEI, as seen in Figure 19. The elemental analysis comparison is shown in Table 17.

[0136] [Table 17]

[0137] Example 9 – Use of linear PEI and variation of chain length Similar linear PEI-functionalized materials were made using trimethoxysilylpropyl-modified polyethyleneimines (1.5-1.8 kDa) (synthetic methods below). Alkylation reactions were carried out with different iodoalkanes of different carbon chain lengths using standard methods. The materials were compared to branched PEI analogs below.

[0138] The data suggests that some of these linear PEI functionalized materials perform as well as their branched counterparts. With respect to carbon chain length, butyl shows significantly reduced performance, while C>6 performs equally well. Batch data for PFAS performance is shown in Figure 20.

[0139] Synthesis method of linear PEI-alumina Alumina 8 (50 g) was carefully weighed into a tared Duran bottle containing isopropyl alcohol (250 mL), then slurried and poured into a 1 L three-neck flask in a heating block with a 10 cm overhead stirring impeller rotating at 150 rpm during the addition. 1.65 kDa linear PEI modified propyl-trimethoxysilane (66 mL, 50% in IPA) was added and the reaction mixture was stirred at 65° C. overnight. After cooling, the powder was allowed to settle and then the reaction solution was removed. The crude product was then washed with IPA (3×250 mL), stirred for about 45 minutes and then allowed to settle for about 15 minutes. The washed material was then filtered through a sintered funnel and dried in a vacuum oven at 80° C. (30 mbar) for about 4 hours. The elemental analysis is shown in Table 18 below.

[0140] [Table 18]

[0141] Although specific embodiments of the present invention have been disclosed in detail herein, this has been done by way of example and for illustrative purposes only. The above-described embodiments are not intended to be limiting in terms of the following appended claims. It is contemplated by the inventors that various substitutions, modifications and alterations may be made to the present invention without departing from the spirit and scope of the present invention as defined by the claims.

Claims

1. 1. A composition for removing a target substance from a fluid stream, comprising: a support material comprising alumina; a sorbent molecule comprising a core polymer; Including, the core polymer is covalently bonded to the support material; The composition, wherein the sorbent molecule further comprises one or more covalently bonded sorbent groups.

2. 2. The composition of claim 1, wherein the support material is comprised of alumina having mesoporous inclusions, with the majority of pores within the mesoporous range being greater than 2 nm in diameter, preferably greater than 3 nm, typically greater than 4 nm in diameter, and optionally greater than 10 nm in diameter.

3. 2. The composition of claim 1, wherein the support material is comprised of alumina with the majority of pores in the mesoporous range being less than 100 nm in diameter, preferably less than 80 nm in diameter, and typically less than 50 nm in diameter.

4. 3. The composition of claim 2, wherein the support material is comprised of alumina having an average pore size in the mesoporous range of 3 nm to 10 nm, optionally 4 to 8 nm.

5. The support material is 0.20 cm ３ / g or more, preferably 0.30 cm ３ / g or more, optionally 0.40 cm ３ 5. The composition of claim 4, having a Brunauer-Emmett-Teller (BET) pore volume of 1 / g or greater.

6. 3. The composition of claim 2, wherein the support material is comprised of alumina having an average pore size in the mesoporous range of 7 to 20 nm.

7. The support material is 0.30 cm ３ / g or more, preferably 0.40 cm ３ / g or more, optionally 0.50 cm ３ 7. The composition of claim 6, having a BET pore volume of at least 1 / g.

8. 3. The composition of claim 2, wherein the support material is comprised of alumina further having macroporous inclusions, with the majority of pores within the macroporous range having an average pore size of 100 nm to 20 μm, optionally 1 μm to 10 μm.

9. 10. The composition of claim 1, wherein the core polymer is selected from one or more of the group consisting of poly(allylamine), poly(methyl methacrylate), poly(vinyl alcohol), poly(vinylamine), poly(vinyl chloride), poly(ethyleneimine), poly(2-vinylpyridine), poly(3-vinylpyridine), and poly(4-vinylpyridine).

10. 10. The composition of claim 9, wherein the core polymer comprises poly(ethyleneimine) having a weight average molecular weight of 25 kDa or greater.

11. The composition according to any one of claims 1 to 10, wherein the core polymer is selected from linear or branched polymers.

12. 11. The composition of any one of claims 1 to 10, wherein the covalently bonded sorbent groups comprise one or more groups selected from substituted or unsubstituted C1 to C12 alkyl groups, substituted or unsubstituted C2 to C12 alkenyl groups, substituted or unsubstituted C2 to C12 alkynyl groups, substituted or unsubstituted C1 to C12 alkoxy groups, substituted or unsubstituted C1 to C12 acyl groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic groups, heterocyclic groups, and hydrogen atoms.

13. 13. The composition of claim 12, wherein the C1 to C12 alkyl group is selected from a branched or linear C1 to C12 alkyl group, optionally a branched or linear C1 to C8 alkyl group.

14. 13. The composition of claim 12, wherein the acyl-containing group is selected from saturated or unsaturated, branched or linear C1 to C12 acyl groups, optionally branched or linear C1 to C8 acyl groups.

15. 11. The composition of any one of claims 1 to 10, wherein the core polymer comprises at least one tertiary amino group, and optionally, the at least one tertiary amino group is converted to a quaternary nitrogen.

16. The composition of claim 11, wherein the core polymer comprises a C1-C10 alkyl-substituted linear poly(ethyleneimine).

17. The composition of claim 11, wherein the core polymer comprises a C1-C6 alkyl-substituted branched poly(ethyleneimine).

18. 17. The composition of claim 16, wherein the linear or branched PEI has a weight average molecular weight of 1 kDa or more, optionally 25 kDa or more.

19. The composition according to any one of claims 1 to 10, wherein the support material is in granular form.

20. The composition of any one of claims 1 to 10, wherein the support material is in powder form.

21. The composition according to any one of claims 1 to 10, wherein the support material is composed of spheroidal particles.

22. 1. A composition for removing poly- and perfluorinated alkyl substances (PFAS) from aqueous liquids, comprising: A particulate support material comprising bimodal alumina having mesoporous and macroporous inclusions, said bimodal alumina having an average particle size of 0.20 cm ３ a particulate support material having a BET pore volume in the mesoporous range of at least 1 / g; sorbent molecules comprising a linear or branched core polymer selected from one or more of poly(allylamine), poly(methyl methacrylate), poly(vinyl alcohol), poly(vinylamine), poly(vinyl chloride), poly(ethyleneimine), poly(2-vinylpyridine), poly(3-vinylpyridine), and poly(4-vinylpyridine); Including, the core polymer is covalently bonded to the support material; The composition, wherein the sorbent molecule further comprises one or more covalently bonded sorbent groups.

23. 23. The composition of claim 22, wherein the particulate support material is comprised of a bimodal alumina having mesoporous inclusions, with the majority of pores in the mesoporous range being greater than 2 nm in diameter, preferably greater than 3 nm, typically greater than 4 nm in diameter, and optionally greater than 10 nm in diameter.

24. 23. The composition of claim 22, wherein the alumina is characterized by a majority of pores in the mesoporous range having a diameter of less than 80 nm, typically less than 50 nm.

25. 25. The composition of any one of claims 22 to 24, wherein the alumina has an average pore size in the mesoporous range of 2 to 20 nm, preferably 3 to 10 nm, optionally 4 to 8 nm.

26. 25. The composition of any one of claims 22 to 24, wherein the particulate support material is comprised of a bimodal alumina with macroporous inclusions, with the majority of pores within the macroporosity range having an average pore size of 100 nm to 20 μm, optionally 1 μm to 10 μm.

27. The composition of any one of claims 22 to 24, wherein the core polymer comprises poly(ethyleneimine) having a weight average molecular weight of at least 25 kDa.

28. 25. The composition of any one of claims 22 to 24, wherein the covalently bonded sorbent groups comprise one or more groups selected from substituted or unsubstituted C1 to C12 alkyl groups, substituted or unsubstituted C2 to C12 alkenyl groups, substituted or unsubstituted C2 to C12 alkynyl groups, substituted or unsubstituted C1 to C12 alkoxy groups, substituted or unsubstituted C1 to C12 acyl groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic groups, heterocyclic groups, and hydrogen atoms.

29. 25. The composition of any one of claims 22 to 24, wherein the core polymer comprises at least one tertiary amino group, and the at least one tertiary amino group is converted to a quaternary nitrogen.

30. 23. The composition of claim 22, wherein the core polymer comprises a C1-C10 alkyl-substituted linear poly(ethyleneimine).

31. 23. The composition of claim 22, wherein the core polymer comprises a C1-C6 alkyl-substituted branched poly(ethyleneimine).

32. 32. The composition of claim 30 or 31, wherein the linear or branched PEI has a weight average molecular weight of 1 kDa or more, optionally 25 kDa or more.

33. A composition according to any one of claims 22 to 24, wherein the support material is in granular form.

34. The composition of any one of claims 22 to 24, wherein the support material is in powder form.

35. A composition according to any one of claims 22 to 24, wherein the support material is composed of spheroidal particles.

36. 10. A process for removing target materials from a fluid stream, comprising contacting the fluid stream with the composition of claim 1, wherein the target materials comprise one or more poly- and perfluorinated alkyl substances (PFAS).

37. 37. The process of claim 36, wherein the fluid comprises water.

38. 38. The process of claim 36 or 37, wherein the PFAS is selected from perfluorinated anionic surfactant compounds including one or more selected from the group consisting of perfluorobutane sulfonate (PFBS), perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexane sulfonate (PFHS), perfluorohexanoic acid (PFHA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA), 6:2 fluorotelomer sulfonic acid (6:2FTSA), and hexafluoropropylene oxide dimer acid (HFPO-DA).

39. 1. A process for removing a target substance from a fluid stream, comprising contacting the fluid stream with a composition, a support material comprised of particulate alumina, and a sorbent molecule comprising a core polymer, wherein the core polymer is covalently bonded to the support material, and the sorbent molecule further comprises one or more covalently bonded sorbent groups selected from one or more groups selected from substituted or unsubstituted C1-C12 alkyl groups, substituted or unsubstituted C2-C12 alkenyl groups, substituted or unsubstituted C2-C12 alkynyl groups, substituted or unsubstituted C1-C12 alkoxy groups, substituted or unsubstituted C1-C12 acyl groups, substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic groups, heterocyclic groups, and hydrogen atoms.

40. 40. The process of claim 39, wherein the support material is comprised of alumina having mesoporous inclusions, with the majority of pores within the mesoporous range being greater than 2 nm in diameter, preferably greater than 3 nm, typically greater than 4 nm in diameter, and optionally greater than 10 nm in diameter.

41. 40. A process according to claim 39, wherein the support material is composed of alumina with the majority of pores in the mesoporous range being less than 100 nm in diameter, preferably less than 80 nm in diameter, typically less than 50 nm in diameter.

42. 41. The process of claim 40, wherein the support material is comprised of alumina having an average pore size in the mesoporous range of 3 nm to 10 nm, optionally 4 to 8 nm.

43. The support material is 0.20 cm ３ / g or more, preferably 0.30 cm ３ / g or more, optionally 0.40 cm ３ 43. The process of claim 42, wherein the SiO2 has a BET pore volume of 1 / g or greater.

44. 42. The process of claim 40 or 41, wherein the support material is comprised of alumina with an average pore size in the mesoporous range of 7 to 20 nm.

45. The support material is 0.30 cm ３ / g or more, preferably 0.40 cm ３ / g or more, optionally 0.50 cm ３ 45. The composition of claim 44, having a BET pore volume of 1 / g or greater.

46. 42. The composition of claim 40 or 41, wherein the support material is comprised of alumina further having macroporous inclusions, with the majority of pores within the macroporous range having an average pore size of 100 nm to 20 μm, optionally 1 μm to 10 μm.

47. 40. The process of claim 39, wherein the core polymer is selected from one or more of the group consisting of poly(allylamine), poly(methyl methacrylate), poly(vinyl alcohol), poly(vinylamine), poly(vinyl chloride), poly(ethyleneimine), poly(2-vinylpyridine), poly(3-vinylpyridine), and poly(4-vinylpyridine).

48. 48. The process of claim 47, wherein the core polymer comprises poly(ethyleneimine) having a weight average molecular weight of 25 kDa or greater.

49. 40. The process of claim 39, wherein the polymer is selected from a linear or branched polymer.

50. 40. The process of claim 39, wherein the C1 to C12 alkyl group is selected from a branched or linear C1 to C12 alkyl group, optionally a branched or linear C1 to C8 alkyl group.

51. 40. The process of claim 39, wherein the acyl-containing group is selected from branched or linear C1 to C8 acyl groups.

52. 40. The process of claim 39, wherein the core polymer comprises at least one tertiary amino group, and optionally, the at least one tertiary amino group is converted to a quaternary nitrogen.

53. 40. The process of claim 39, wherein the core polymer comprises a C1-C10 alkyl-substituted linear poly(ethyleneimine).

54. 40. The process of claim 39, wherein the core polymer comprises a C1-C6 alkyl-substituted branched poly(ethyleneimine).

55. 55. The process of claim 53 or 54, wherein the linear or branched PEI has a weight average molecular weight of 1 kDa or more, optionally 25 kDa or more.

56. 40. The process of claim 39, wherein the particulate alumina is in granular form.

57. 40. The process of claim 39, wherein the particulate alumina is in powder form.

58. 40. The process of claim 39, wherein the particulate alumina is comprised of spheroidal particles.

59. 40. The process of claim 39, wherein the fluid comprises water.

60. 40. The process of claim 39, wherein the target material comprises one or more poly- and perfluorinated alkyl substances (PFAS).

61. 61. The process of claim 60, wherein the PFAS is selected from perfluorinated anionic surfactant compounds including one or more selected from the group consisting of perfluorobutane sulfonate (PFBS), perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexane sulfonate (PFHS), perfluorohexanoic acid (PFHA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA), 6:2 fluorotelomer sulfonic acid (6:2FTSA), and hexafluoropropylene oxide dimer acid (HFPO-DA).

62. 40. The process of claim 39, wherein the support material is contained within a packed bed.

63. 40. The process of claim 39, wherein the support material is contained within a filter unit.

64. 10. A filter for adsorbing one or more PFAS from a contaminated water source, the filter comprising the composition of claim 1.

65. 65. The filter of claim 64, wherein the filter is configured as a point-of-use (POU) filter.

66. 66. The filter of claim 65, wherein the filter is contained within a replaceable cartridge.

67. 65. The filter of claim 64, wherein the filter is configured to be incorporated into a point-of-entry (POE) system.

68. 68. The filter of any one of claims 64 to 67, wherein the filter comprises a combination of granular alumina and powdered alumina.

69. 68. A filter according to any one of claims 64 to 67, wherein the composition is contained within a packed bed configured to allow a minimum water flow rate through of at least 2 litres / minute.

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