Filter media, method of manufacture thereof and articles comprising the same

Abstract

Disclosed herein is a filter media comprising cellulosic fibers; a positively charged binder; and adsorbent particles; where the filter media is operative to remove per- and polyfluoroalkyl moieties.

Description

P4477WO (AMJ0053PCT)FILTER MEDIA, METHOD OF MANUFACTURE THEREOF AND ARTICLES COMPRISING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONThe present application is an international filing which claims priority to and the benefit of United States Patent Application Number 63 / 700278, which was filed on September 27, 2024. The entire contents of the foregoing application are incorporated herein by reference. BACKGROUND

[0001] This disclosure relates to filter media, methods of manufacture thereof and to articles comprising the same. In particular, this disclosure relates to water filter media, methods of manufacture thereof and articles comprising the same.

[0002] In water filtration technology, it is desirable to enhance filtration performance by removing contaminants more efficiently. One issue in water purification is the removal of a wide diversity of contaminants, including physical contaminants like dirt and dust, chemical contaminants such as chlorine, chloramines, soluble and insoluble lead, arsenic, and biological contaminants like viruses, bacteria and parasites. The variability in water source quality and characteristics, emergence of new contaminants and new legislations that requires more stringent standards for existing contaminants, present additional challenges to develop higher quality water filtration systems. In addition to the aforementioned contaminants, governments and agencies worldwide have established or are starting to establish more stringent guidelines to address per- and / or polyfluoroalkyl substances (PFAS) contamination in water.

[0003] Due to these lower permissible levels, water filters now need to be even more efficient and multiple steps or modes of treatments may likely be desirable to remove the contaminants, especially shorter chain PFAS (those containing less than 8 carbon atoms).

[0004] It is therefore desirable to provide a filter media which efficiently allows for the removal of PFAS and biological contaminants at the same time from fluids, especially drinking water.P4477WO (AMJ0053PCT)SUMMARY

[0005] Disclosed herein is a filter media comprising cellulosic fibers; a positively charged binder; and adsorbent particles; where the filter media is operative to remove per- and pol lluoroalkyl moieties.

[0006] Disclosed herein too is a method of manufacturing a filter media, the method comprising blending together water, cellulosic fibers; a positively charged binder; and adsorbent particles to form a slurry; where the positively charged binder is present in an amount of less than 5 wt%, where the cellulosic fibers arc present in an amount of up to 65 wt%, and where the positively charged binder is present in an amount of 1 to 5 wt%, based on a total weight of the filter media; transporting the slurry to a headbox of a paper-making machine; applying the slurry onto a wire conveyor in the papermaking machine to form a fibrous web; and applying a continuous vacuum during the applying of the slurry onto the wire conveyor; and drying the fibrous web to manufacture the filter media.BRIEF DESCRIPTION OF THE FIGURES

[0007] FIG. 1 is a graph that depicts percent reduction in PFAS versus flow volume in liters per square meter.DETAILED DESCRIPTIONDefinitions

[0008] The folding resistance of filter media is defined as the ability of the filter material to withstand repeated folding or creasing without experiencing significant degradation in its structural integrity or filtration performance. Folding resistance is expressed as the number of times the media is folded before breaking or tearing.

[0009] Biodegradable refers to the ability of a substance or material to be broken down naturally by microorganisms, such as bacteria, fungi, or other biological processes, into simpler, non-toxic substances, like water, carbon dioxide, and biomass. This breakdown occurs over time and leaves no harmful residues, allowing the material to be reintegrated into the natural environment.

[0010] The EN 13432:2000 standard is a European industrial compostability certification for packaging materials. It specifics the requirements for packagingP4477WO (AMJ0053PCT) recoverable through composting and biodegradation, ensuring that the material can be processed in industrial composting facilities without negatively impacting the environment. The material must biodegrade into carbon dioxide, water, and biomass through microbial action. This is assessed by measuring the amount of carbon dioxide produced when the material is composted. At least 90% of the organic carbon in the material must convert to CO2 within 180 days. The material must break down into fragments that are indistinguishable in the compost. After 12 weeks, less than 10% of the original material's dry weight should remain on a 2 mm sieve.

[0011] The OK Compost Home certification standard is a certification provided by TUV Austria (formerly Vincotte) that ensures a product or material is compostable in a home composting environment. This certification indicates that the product can break down in a home compost pile under typical home composting conditions, without harming the environment or leaving toxic residues. Generally, this period is around 6 months, but it may vary based on specific requirements and conditions.

[0012] A modified version of the OK compostability test can also be conducted: The disintegration of samples placed in a compost bin at room temperature and pressure is measured over a period of 6 months. The samples all have the same grammagc and test area. Samples are placed in a compost bin and covered in soil. The disintegration of the samples is measured over a period of 6 months, by visual inspection, and samples which have been completely digested are no longer visible. Samples are considered fully biodegradable if they disintegrate completely by 6 months (180 days).

[0013] Stiffness in filter media indicates how much force is used to bend or deform the material. Stiffness is often measured in milligrams (mg), which indicates the mass that can be supported or resisted by the material without significant deformation.

[0014] In the context of filtration, the terms “6-log bacterial removal” and “3-log or 4-log virus removal” refer to the effectiveness of the filter media in reducing the concentration of bacteria and viruses, respectively. These terms use logarithmic scales to quantify the reduction in microbial load. A 1-log reduction corresponds to a 10-fold (or 90%) reduction in the number of microorganisms. A 2-log reduction corresponds to a 100-fold (or 99%) reduction. A 3-log reduction corresponds to a 1 ,000- fold (or 99.9%) reduction. A 6-log reduction corresponds to a 1,000,000-fold (or 99.9999%) reduction.P4477WO (AMJ0053PCT)

[0015] The pore size is measured according to the American Society of Testing and Materials (ASTM) Standard 316-03 (2011). The pore size is measured using a technique known as capillary flow porosimctry. The sample is first wetted with a wetting fluid such that all the pores in the sample are filled. A nonreacting gas of increasing pressure is applied to one side of the wet sample to displace the liquid from the pores. The gas pressure and gas flowrate downstream of the sample are measured and plotted for the wet sample. After the sample is dry, the test is repeated to plot a gas flow vs. the applied pressure curve for the dry sample. Using such capillary porosimctry technique, the “maximum pore size”, “minimum pore size” and “mean flow pore size” can be determined.

[0016] Maximum Pore Size: The gas pressure using the capillary flow porosimetry technique described hereinabove at which air flow through the media is first detected (i.e. the pressure at which the bubbles first begin to flow) is used to calculate the maximum pore size.

[0017] Minimum Pore Size is determined from the pressure at which the wet flow rate curve merges with dry curve using the capillary flow porosimetry technique described hereinabove.

[0018] Mean Flow Pore Size is the pore diameter at which the flow through a wetted medium is 50% of the flow through the dry medium at the same pressure drop using the capillary flow porosimetry technique described hereinabove.

[0019] “Fibers” refers to material with aspect ratio above 3: 1 and average lengths above 0.2mm.

[0020] “Fibrillation” refers to a process where the fibers are mechanically or chemically treated to create fine, hair-like strands or fibrils on their surface.

[0021] “Fibrillated fibers” means fibers that have been further acted upon to create numerous fibrils. Fibrillated Fibers, are preferably characterized by a Canadian Standard Frccncss, measured according to TAPP1 T227 om-94, of about 300 mL or less, preferably about 200 mL or less, typically between about 1 to about 200 mL

[0022] “Fibrils” are tiny, minute irregular threadlike elements of a fiber that has been fibrillated by a fibrillation process.

[0023] “Non-fibrillated” means unprocessed fibers having essentially no fibrils and which exhibit a Canadian Standard Frccncss of greater than about 500 mL.P4477WO (AMJ0053PCT)

[0024] Synthetic cellulosic fibers are made by direct dissolution and spinning of wood pulp in an organic solvent, such as an amine oxide.Detailed Description

[0025] Disclosed herein is a filter media that may be advantageously used to remove per- and polyfluoroalkyls (PFAS) from drinking water. In an embodiment, the filter media comprises fibers, an adsorbent, a positively charged binder and optionally positive charged particles or fibers. When the positively charged particles or fibers arc used in the filter media, the amount of the positively charged binder may be reduced to less than 1 wt%, preferably less than 0.5 wt%, based on a total weight of the filter media. If no positively charged particles or fibers are used, then the amount of the positively charged binder may be increased to an amount greater than 1 wt%, preferably in an amount of 1 to 5 wt%, based on a total weight of the filter media.

[0026] In particular, the environmental protection agency (EPA) has identified 6 key PFAS species: perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS) and hcxafluoropropylcnc oxide dimer acid for regulation due to their widespread use, extensive study, and clear health advisories. These six PFAS include four legacy chemicals — PFOA, PFOS, PFHxS, and PFNA — which have been used for decades in products like TEFLON and firefighting foams. The other two, PFBS and HFPO-DA (GenX), are newer variants introduced as supposedly safer alternatives but exhibit similar persistence and health risks. Some of the foregoing PFAS arc short chain PFAS (having fewer than eight carbon atoms in their molecular structure, making them more difficult to remove).

[0027] More recently, the EPA has announced stricter maximum allowable limits for the aforementioned PFAS species as shown below in Table 1.Table 1P4477WO (AMJ0053PCT)

[0028] Current known filtration methods to reduce PFAS include reverse osmosis, ion exchange resin beds and activated carbon. However, these alone are not sufficient in keeping PFAS in drinking water below the proposed limits. In fact, in many countries drinking water contains PFAS above the proposed limits of the respective governmental bodies. An additional problem is that in many cases, filtration media that work well for chemical contaminants like PFAS often don’t also remove biological contaminants well. One of the primary known causes of failure in water filters is biofouling, when microbials like bacteria and fungi form biofilms. Viruses, particularly bacteriophages (viruses that infect bacteria), can integrate into bacterial biofilms, potentially enhancing the biofilm’s formation and stability, making it harder to remove.

[0029] As noted above, the filter comprises a fibrous material, a positively charged binder that contacts the fibrous material, which may be a cationic binder, and at least one adsorbent.

[0030] In an embodiment, the at least one fibrous material may comprise cellulosic fibers combined optionally with other fibers such as polyester fibers and glass fibers. The cellulosic fibers may be biodegradable. The fibers have an average aspect ratio (ratio of average length to average diameter) of greater than or equal to 3:1, while the particulates (such as the adsorbents) have an aspect ratio that is less than 3: 1. Both the polyester and glass fibers are optional and may be avoided in a biodegradable compostable filter.

[0031] In an embodiment, the cellulosic fibers comprise fibrillated fibers and / or non-fibrillatcd fibers. The cellulosic fibers may comprise a blend of fibrillated and non- fibrillated fibers. In an embodiment, the cellulosic fibers are preferably fibrillated. Fibrillation is a process where the fibers are mechanically or chemically treated to create fine, hair-like strands or fibrils on their surface. The fibrillated cellulosic fibers preferably have fibrillation levels less than 300 ml Canadian Standard Freeness (CSF), preferably less than 200 ml CSF, preferably less than 100 ml CSF, preferably less than 60 ml CSF, and more preferably less than 50 ml CSF as specified by TAPPI test method T 227 om-9494 (Freeness of Pulp). The “fibrillation level” refers to the degree or extent toP4477WO (AMJ0053PCT) which the fibers have been split or fibrillated into smaller fibrils. Canadian Standard Freeness is a measure of the drainage rate of a fiber suspension, often used in the pulp and paper industry to evaluate the fibrillation level of fibers. Lower CSF values (below 100 ml) indicate a higher degree of fibrillation.

[0032] The fibrillated cellulosic fibers may include parent fibers and fibrils. The parent fiber is the original, larger fiber from which the fibrils are derived. These fibers are typically long and continuous, forming the primary structural component before the fibrillation process begins. The parent fibers provide the main strength and bulk of the material. They are responsible for the overall integrity of the fiber mat or fabric.

[0033] The fibrillated cellulosic fibers preferably have an average parent fiber diameter of 5 to 30 micrometers, more preferably 10 to 20 micrometers and most preferably around 10 to 15 micrometers. The fibrils preferably have an average diameter of 1000 nanometers or less, more preferably 400 nanometers or less, and most preferably 100 nanometers or less. Some preferred embodiments will include fibrils having average diameters of 250 to 350 nanometers. Average fiber diameter can be measured using Scanning Electron Microscopy (SEM) by averaging the measurements of over 50, preferably over 100 fibers. In this method, handshcct samples made exclusively of the fibers are placed in the SEM chamber, where an electron beam scans the samples, producing high-resolution images. These images are analyzed using specialized software to measure the diameters of individual fibers. By averaging these measurements, a representative average fiber diameter is obtained. Alternatively, the average fiber diameter can be calculated using the dtex / denier, fiber length and material density of the fiber, all of which are provided by the supplier.

[0034] The preferred average length of the fibrillated cellulosic fibers is 0.4 to 8 millimeters, more preferably 1 to 6 millimeters. In addition, in preferred embodiments, less than 15% of the fibers have a length- weighted average fiber length (LWAFL) of greater than 2 millimeters. Fiber length is measured with any suitable equipment that follows ISO 16065-1:2014 or ISO 16065-2:2014. A suitable equipment can be for example, Morfi TECHPAP which follows the ISO 16065-2:2014 standard.

[0035] The fibrillated cellulosic fibers preferably have an average parent fiber diameter of 5 to 30 micrometers, more preferably 10 to 20 micrometers and most preferably around 10 to 15 micrometers. The fibrils preferably have an average diameterP4477WO (AMJ0053PCT) of 1000 nanometers or less, more preferably 400 nanometers or less, and most preferably 100 nanometers or less. Some preferred embodiments will include fibrils having average diameters of 250 to 350 nanometers.

[0036] The preferred average length of the fibrillated fibers is 0.4 to 8 millimeters, more preferably 1 to 6 millimeters. The fibrillated cellulose fibers can be naturally occurring fibers, synthetic fibers or a combination of both.

[0037] In an embodiment, preferred fibrillated cellulosic fibers include synthetic cellulose fibers such as viscose, rayon, lyoccll, or the like. Preferred fibrillated cellulosic fibers are those made by a synthetic process, such as for example direct dissolution and spinning of wood pulp in an organic solvent, such as an amine oxide and are known as Lyocell fibers. The fibrillated cellulose fibers may be fibrillated either during the fiber production process, or by being subjected to standard mechanical beaters, refiners and the like employed in the paper-making industry. The fibrillated cellulosic fibers are present in an amount of 2 to 60 wt%, preferably 3 to 55 wt%, and more preferably 4 to 50 wt%, based on the total weight of the filter media.

[0038] The non-fibrillated fibers also preferably comprise cellulose. The non- fibrillatcd cellulosic fibers can be from woody and non- woody plants. They can include hardwood and / or softwood fibers. Woody plants include, for example, deciduous (hardwood), coniferous trees (softwood), or the like, or a combination thereof. Non- woody plants include, for example, cotton, flax, esparto grass, kenaf, sisal, abaca, milkweed, straw, jute, hemp, bagasse, or the like, or a combination thereof.

[0039] Examples of softwood fibers include fibers obtained from chemical treatments like mercerization (e.g., HPZ fibers), northern bleached softwood kraft (e.g., 1'ibers from Redwoods, Douglas firs, Western red cedar, or the like), southern bleached softwood kraft (e.g., fibers from slash pine, loblolly pine, or the like), or chemically treated mechanical pulps (e.g., CTMP fibers), or the like, or a combination thereof. Exemplary hardwood fibers include fibers obtained from eucalyptus, birch, aspen, beech, oaks, gum tees, or the like, or a combination thereof. The non-fibrillated cellulosic fibers are preferably cellulose pulp fibers and more preferably comprise large diameter softwood fibers (e.g. Northern Bleached Softwood Kraft (NBSK), Southern Bleached Softwood Kraft (SBSK),), or a combination thereof). The cellulose pulp fibers are larger diameter fibers than the fibrillated fibers, which can add rigidity and stiffness to the filterP4477WO (AMJ0053PCT) media. The non-fibrillated fibers may have an average fiber diameter that is greater than the average fiber diameter of the fibrillated fibers.

[0040] The non-fibrillated cellulosic fibers preferably have an average fiber diameter of 10 to 55 micrometers, more preferably 15 to 50 micrometers. The non- fibrillated cellulosic fibers preferably have an average fiber length, as measured with any suitable equipment that follows ISO 16065- 1 :2014 or ISO 16065-2:2014, of 0.3 to 8 millimeters, more preferably from 1 to 6 millimeters, more preferably from 3 to 6 millimeters.

[0041] In an embodiment, the non-fibrillated cellulosic fibers have an average aspect ratio (calculated as the ratio of average fiber length to average fiber diameter) of 4 to 800, preferably 10 to 500.

[0042] The non-fibrillated cellulosic fibers are present in the filter media in an amount of up to 75 wt%, preferably 3 to 70 wt% and more preferably 4 to 60 wt%, based on the total weight of the filter media.

[0043] The filter media may also contain other non-cellulosic fibers that may include non-cellulosic synthetic polymeric fibers and glass fibers. The non-cellulosic synthetic polymeric fibers arc preferably insoluble in water. They can reinforce the filter media and provide it with strength when in the presence of a liquid that is to be filtered. These fibers are often selected for their durability, resistance to chemicals or their structural dimensions depending upon specific filtration needs.

[0044] Non-cellulosic synthetics polymeric fibers may comprise thermoplastic or thermoset polymers. Examples of thermoplastic or thermoset polymers for use in the filter media include a polyolefin, a polyester, a polyamide, a polyaramid, a polyamideimide, a polyarylate, a polyurethane, a polysiloxane, a polyimide, a polyetherimide, a polytetrafluoroethylene, a polyetherketone, or the like, or a combination thereof.

[0045] Preferred non-cellulosic synthetic polymeric fibers include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, or the like, or a combination thereof. The polyester fibers may be used in the form of spunbond or meltblown fibers. The non-cellulosic fibers may be single component or bicomponent core / sheath type fibers.P4477WO (AMJ0053PCT)

[0046] The non-cellulosic synthetic polymeric fibers may have an average diameter of less than less than 25 micrometers, preferably less than 20 micrometers, and preferably less than 18 micrometers. The non-cellulosic polymeric fibers may have an average diameter of greater than 1 micrometer, preferably greater than 2 micrometers and more preferably greater 5 micrometers.

[0047] The non-cellulosic synthetic polymeric fibers may have an average length of less than 15 mm, preferably less than 12 mm, preferably less than 10 mm, preferably less than 8 mm. For example, the average length of the non-cellulosic synthetic polymeric fibers may be 0.1 to 15 mm, between 1 and 10 mm, between 2 and 8 mm, between 3 and 6 mm.

[0048] The non-cellulosic synthetic polymeric fibers may optionally be used in amounts of 4 to 30 wt%, preferably 5 to 25 wt%, based on the total weight of the filter media.

[0049] In another embodiment, the non-cellulosic fibers used in conjunction with the cellulosic fiber and / or the non-cellulosic synthetic polymeric fibers may be glass fibers. The glass fiber can comprise E, A, B, C, ECR, R, S, D, or NE glass, or the like, or a combination thereof. In an embodiment, two or more different types of glass fibers may be used in the filter media. When two or more types of glass fibers are used, each type may have a different average length and / or a different average diameter prior to incorporation in the filter media. Preferably, the glass fibers are micro-glass fibers with diameters indicated below.

[0050] The glass fibers detailed above can be made by standard processes, c.g., by steam or air blowing, flame blowing, and mechanical pulling. Exemplary glass fibers are made by mechanical pulling.

[0051] The glass fiber can be chopped fibers. Glass fibers in the form of chopped strands can have a length of 0.3 millimeters (mm) to 10 centimeters (cm), preferably 0.5 mm to 5 cm, and more preferably 1 mm to 2.5 cm. For example, the glass fiber can be a microglass fiber. The microglass fibers can have a length from 0.2 to 20 mm, preferably 0.25 to 10 mm, and more preferably 0.3 to 6 mm.

[0052] The fibers can have any cross-section, such as a round (or circular), flat, or irregular cross-section. For example, the glass fiber has a circular cross-section. The diameter of the glass fiber can be from 0.1 to 25 micrometers (pm), preferably 0.2 to 20P4477WO (AMJ0053PCT) pm, preferably 0.3 to 15 pm. For example, the glass fiber can be a microglass fiber, with a diameter from 0.1 to 10pm, preferably 0.2 to 8pm and more preferably 0.3 to 6pm. Flat glass or bilobc glass fibers can be used to provide, for example, low warp-high strength articles.

[0053] The glass fibers may optionally be used in amounts of 5 to 40 wt%, preferably 8 to 35 wt%, and more preferably 10 to 30 wt%, based on the total weight of the filter media. When two or more types of glass fibers are simultaneously used in the filter media, the first type may be used in an amount of 5 to 15 wt%, preferably 6 to 12 wt%, based on the total weight of the filter media. The second type may be used in an amount of 10 to 20 wt%, preferably 11 to 16 wt%, based on the total weight of the filter media.

[0054] The total fibrous content (the total weight of the fibrillated and non- cellulosic fibers, non-cellulosic synthetic polymeric fibers and / or glass fibers) in the filter media may be 25 to 90 wt%, preferably 40 to 85 wt%, preferably 45 to 70 wt%, and more preferably 55 to 65 wt%, based on the total weight of the filter media.

[0055] As noted above, the filter media may contain positively charged particles or fibers. In a preferred embodiment, the filter media may contain positively charged nano-alumina disposed on the fibers. The positively charged nano-alumina, which is primarily composed of the mineral boehmite, is produced by reacting aluminum powder (in metallic form) with a base (usually 50% NaOH in water) in the pulper. The fibers listed above are also added into the pulper before the reaction. The pulper is a machine or device used to mix and / or break materials into a pulp-like consistency. Due to the reaction between aluminum and the base in the pulper, positively charged nano-alumina is formed and are disposed on the surface of the fibers. Once the reaction is complete, sulfuric acid or another suitable acid is added to the pulper to neutralize the reaction.

[0056] In an embodiment, the nano-alumina may be disposed on at least one of the fibers present in the filter media - the cellulosic fibrillated fibers, the cellulosic non- fibrillated fibers, the non-cellulosic synthetic polymeric fibers and the glass fibers. In another embodiment, the nano-alumina may be disposed on at least two of the fibers listed above - the cellulosic fibrillated fibers, the cellulosic non-fibrillated fibers, the non- cellulosic synthetic polymeric fibers and the glass fibers. In yet another embodiment, the nano-alumina may be disposed on all of the fibers listed above - the cellulosic fibrillatedP4477WO (AMJ0053PCT) fibers, the cellulosic non-fibrillated fibers, the non-cellulosic synthetic polymeric fibers and the glass fibers.

[0057] Typically, the filter media can comprise up to 65 wt% positively charged nano-alumina, preferably 15 to 60 wt%, and more preferably 30 to 40 wt%, based on a total weight of the filter media. As will be detailed later, the use of positively charged particles or fibers in the filter media facilitates the use of a smaller amount of the positively charged binder than if the filter media does not contain the positively charged particles or fibers.

[0058] The filter media may also contain adsorbents. Adsorbents are added to filter media to enhance the filtration process by removing specific contaminants and improving the filters effectiveness in various applications. They play a valuable role in capturing and retaining substances primarily through adsorption (the adherence of molecules to the surface of the adsorbent) but may also include some level of absorption (the uptake of substances into the material itself).

[0059] Examples of adsorbent particles include activated carbon, diatomaceous earth, silica, porous glass, zeolites, alumina, activated alumina, ion exchange resins, silica gel, molecular sieves, chitosan, rice husk, straw, crystalline materials such as y-alumina, zirconia, cellulose nanocrystals (CNC), cyclic oligosaccharides such as cyclodextrin, titania, clay minerals, or the like, or a combination thereof. Activated carbon, cyclodextrin and ion-exchange resins are preferred, with catalytic activated carbon being an especially preferred option. In some embodiments, a mixture of adsorbent particles may be used in combination such as a mixture of activated carbon powder and cyclodextrin. Adsorbent particles with high surface area (e.g., granular activated carbon, mesoporous material like cyclodextrins) and / or modified surface chemistry (e.g., catalytic activated carbon) are preferred. Surface area is defined by iodine numbers greater than 700mg / g, preferably greater than 900mg / g, and more preferably thanllOOmg / g. This method measures the amount of iodine adsorbed by the adsorbent particle from an iodine solution. The iodine number is an indicator of the micropore content of the adsorbent particle and is often used as a quick test for surface area. It is believed that adsorbent particles with a high microporous structure (e.g., a high surface area) are especially beneficial for PFAS removal, as they provide more adsorption sites for small, persistentP4477WO (AMJ0053PCT) short-chain PFAS such as perfluorobutanoic acid and hexafluoropropylene oxide dimer acid.

[0060] In an embodiment, the BET surface area of adsorbent particles may be greater than or equal to 900m2 / g, preferably greater than or equal to 1000m2 / g, and more preferably greater than or equal to 1200 nr / g. BET (Brunauer-Emmett-Teller) is used to measure surface area of material. Tt involves measuring the amount of nitrogen gas adsorbed onto the surface of the adsorbent particles at various pressures. The data is then used to calculate the surface area based on the BET theory.

[0061] Activated carbon (also known as activated charcoal) is a highly porous form of carbon with a large surface area, making it an effective material for adsorption. Catalytic activated carbon (CAC) is a specially treated form of activated carbon that has enhanced catalytic properties, allowing it to not only adsorb contaminants but also chemically react with them to break them down into less harmful or non-toxic substances. CAC’s contain copper manganese, manganese oxide, iron, iron oxide, cobalt, silver, nitrogen functional groups, oxygen functional groups (e.g., carboxyl, hydroxyl, or carbonyl groups), and halogens to facilitate catalytic action during absorption.

[0062] Ion exchange resins may also be preferably added to the filter media as adsorbents. Ion exchange resins used in water filtration comprise polymers and copolymers that are chemically designed to carry functional groups that allow them to exchange ions with contaminants in water, helping to remove impurities such as heavy metals, hardness ions (calcium, magnesium), and other undesirable ions. Examples of ion exchange polymers that may be used in the filtration media include polystyrcnc- divinylbenzene (PS-DVB), polyacrylic or methacrylic acid copolymers, polyethyleneimine (PEI) copolymers, epoxy-amine crosslinked polymers, phenolic resins such as phenolic-formaldehyde resins, iminodiacetate and thiol-based resins, polyvinyl alcohol (PVA)-based resins, or the like, or a combination thereof.

[0063] Adsorbents arc added to the filter media cither at the pulper or added at the headbox during the manufacturing of the filter media. The filter media may contain adsorbent particles in an amount of up to 60 wt%, preferably 10 to 55 wt% and more preferably 12 to 40 wt%, based on the total weight of the filter media.

[0064] In an embodiment, the filter media contains one or more binders. The binders play a useful role in holding various components of the filter media together,P4477WO (AMJ0053PCT) ensuring structural integrity and enhancing the performance of the filter. The hinders may be bonding agents that help maintain the form and functionality of the filter media while allowing the filter media to remain porous and effective in capturing particles or contaminants.

[0065] In an embodiment, the filter media may contain a positively charged binder and / or a non-positively charged binder. The positively charged binder is a cationic polymer. In an embodiment, the positively charged binder and / or the non- positively charged binder may each comprise a thermoplastic polymer, a blend of thermoplastic polymers, a thermosetting polymer (e.g., a crosslinkable or crosslinked polymer), or a blend of a thermoplastic polymer with thermosetting polymers. These polymers may comprise an oligomer, a homopolymer, a copolymer, a block copolymer, an alternating block copolymer, a random copolymer, a graft copolymer, a star block copolymer, a dendrimer, a polyelectrolyte (polymers that have some repeat groups that contain electrolytes), a polyampholyte (a polyelectrolyte having both cationic and anionic repeat groups), an ionomer, or the like, or a combination thereof.

[0066] In an embodiment, the positively charged binder is a crosslinkable polymer that undergoes crosslinking during the process of manufacturing the filter media. The positively charged binder in the final filter media product is typically crosslinked.

[0067] The positively charged binder may be any polymer bearing an overall positive charge, such as, for example, a polyethyleneimine (PEI), a polyamidoamine, a polylysine, a poly (allylamine), a poly(diallyldimethylammonium chloride), a poly(N- isopropyl acrylamidc-co-acrylamidc), a poly(N-isopropyl acrylamidc-co-acrylic acid), a poly(L-lysine), a diethylaminoethyl-dextran copolymer, a poly-(N-ethyl-vinylpyridinium bromide), a poly(-dimethylamino)ethyl methacrylate), a poly(ethylene glycol)-co- poly(trimethylaminoethylmethacrylate chloride), an epichlorohydrin based polymer, a polyamide, an epichlorohydrin-dimethylamine copolymer, a polyamide-epichlorohydrin (PAE), or the like, or a combination thereof.

[0068] Preferred positively charged binders may include epichlorohydrin containing polymers. Epichlorohydrin is advantageous because it reacts with hydroxyl groups, making it useful in crosslinking polysaccharides such as starch, cellulose, or polyvinyl alcohol (PVA). In polymers or biomaterials, epichlorohydrin can be used to introduce crosslinks that enhance mechanical strength, chemical resistance, and stability.P4477WO (AMJ0053PCT)

[0069] In an embodiment, the preferred positively charged binders include a crosslinkable epichlorohydrin based polymer, a crosslinkable polyamide, a crosslinkable cpichlorohydrin-dimcthylaminc copolymer, a crosslinkablc polyamidc-cpichlorohydrin (PAE), or a combination thereof. A preferred positively charged binder is polyamideepichlorohydrin (PAE).

[0070] The positively charged binder may be bound covalently and / or electrostatically to the surface of the cellulosic fibers. In some embodiments, the positively charged binder is electrostatically bound to the surface of the cellulosic fibers. For example, the positively charged binder may bind electrostatically to the surface of the cellulosic fibers, which have an overall negative charge. In an embodiment, hydrogen bonding may occur between the positively charged binder and the biodegradable fibers. The electropositive nature of the filter media is at least, in part, due to the impregnation of the fibers by the positively charged binder.

[0071] The positively charged binder or the non-positively charged binder may have a number average molecular weight (Mn) greater than 10,000 grams per mole, preferably greater than 20,000 g / mole and more preferably greater than 50,000 g / mole. In an embodiment, the positively charged binder or the non-positively charged binder may have a number average molecular weight (Mn) of less than 2,000,000 g / mole, preferably less than 1,000,000 g / mole.

[0072] The positively charged binder is preferably used in an amount of less than or equal to 5 wt%, preferably less than or equal to 2.5 wt%, and more preferably less than or equal to 2.0 wt%, based on a total weight of the filter media. In an embodiment, the positively charged binder is present in an amount of greater than or equal to 0.5 wt%, preferably greater than or equal to 1 wt%, based on a total weight of the filter media.

[0073] In addition to the positively charged binder, other non-positively charged binders may also be added to the filter media. The non-positively charged binders are typically in emulsion form (i.c., they arc latex-based binders). Emulsion polymers arc a class of polymers produced through a process called emulsion polymerization, where monomers (small molecules) are polymerized in an emulsion containing water, surfactants (emulsifiers), and initiators. This technique is widely used in the production of polymers that are water-borne. In an emulsion, water typically forms the continuous phase. Surfactants arc used to stabilize the polymer particles in the water.P4477WO (AMJ0053PCT)

[0074] Examples of non-positively charged binders (that may he used in conjunction with the positively charged polymeric binders) that may be used in emulsion form include polyethylene, polypropylene, polyester, polyurethane, phenolic resin, acrylic resin, silicone resin, nitrile rubber (acrylonitrile-butadiene rubber), or the like, or a combination thereof.

[0075] The non-positively charged binders preferably in latex form are included in the filter material in amounts of up to 5 wt%, preferably in amounts of up to 3 wt%, and more preferably in amounts of up to 2 wt%, based on a total weight of the filter media.

[0076] The total amount of binders (positively charged binders and non-positively charged binders) in the media is typically less than 10 wt%, preferably less than 6 wt%, and more preferably less than 4 wt%, based on a total weight of the filter media.

[0077] The amount of the positively charged binder may be in an amount greater than 1 wt%, preferably in an amount greater than 1.25%, more preferably in an amount greater than 1.5%, preferably in an amount of 1 to 5 wt%, based on a total weight of the filter media. When the positively charged particles or fibers (e.g., nanoalumina) is used in the filter media, the amount of positively charged binder may be reduced. Preferably the amount of positively charged binder in such embodiments is in an amount of greater than or equal to 0.5 wt%, preferably greater than or equal to 0.7% and more preferably greater than or equal to 1% based on a total weight of the filter media.

[0078] In an embodiment, the positively charged binders and non-positively charged binders may be added simultaneously or sequentially to the pulper or to the headbox during the manufacturing of the filter media. In an embodiment, it is desirable to add the positively charged binders and non-positively charged binders sequentially during the manufacturing of the filter media. When sequential addition is used, the positively charged binder is first added before the non-positively charged binder is added. This is done to maximize the electropositive charge on fiber surfaces in the filter media.

[0079] In one embodiment, in one method of producing the filter media, the fibrillated fibers and the non-fibrillated fibers, the non-cellulosic polymeric fibers and the glass fibers are mixed together in a pulper (in a paper machine) along with water to form a fiber mixture. The positively charged particles or fibers (e.g., nanoalumina), the adsorbents and the binders (e.g., positively charged binders and / or non-positively chargedP4477WO (AMJ0053PCT) binders) may also be added to the fiber mixture in the pulper to form a slurry. In an embodiment, the positively charged binder is first added to the pulper before the non- positivcly charged binder is added.

[0080] There is no refining applied to the fiber mixture. The slurry and the constituents are allowed to mix together before the slurry is transferred to the headbox and further diluted. The diluted slurry is applied onto a wire conveyor in a papermaking machine (e.g., a fourdrinier or a rotoformer) to form the filter media. Vacuum is continuously applied during the aforementioned processes to remove the solvent from the mixture and / or the slurry, thereby producing a fibrous web. The web thus formed, is subsequently dried to form the filter media and wound into a roll.

[0081] Tn an embodiment, some of the ingredients may be added to the fiber mixture in the headbox instead of at the pulper. For example, the positively charged binder may be added to the liber mixture in the pulper, while the non-positively charged binder may be added to the slurry in the headbox. In a similar manner, some of the adsorbents (e.g., the ion exchange resin or the activated carbon) may be added to the slurry at the headbox instead of at the pulper.

[0082] The slurry' and the constituents contained therein arc allowed to mix together before the slurry is transferred to the headbox and further diluted. The diluted slurry is applied onto a wire conveyor in a papermaking machine (e.g., a fourdrinier or a rotoformer) to form the filter media. Vacuum is continuously applied during the aforementioned processes to remove the solvent from the mixture and / or the slurry, thereby producing a fibrous web. The web thus formed, is dried to form a filter media and wound into a roll.

[0083] In an embodiment, this filter media may be used in combination with other layers, wherein the filter media serves either as a pre-filter or a post-filter to the other layer(s). Optionally, an additional layer may be laminated on one or both sides of the filter media. The additional layer may function as a mechanical support, a filtration layer and / or may also be a protective layer to prevent adsorbent particles from leaching out. In an embodiment, one or more of the layers contains nano-alumina.

[0084] The resulting filter media has a maximum pore size of less than 10 micrometers, preferably less than 5 micrometers. In an embodiment, the resulting filterP4477WO (AMJ0053PCT) media has mean flow pore size less than 8 micrometers, preferably less than 4 micrometers.

[0085] In an embodiment, the filter media displays an ability to remove an amount of PF AS of greater than 80 wt% from volumes of 125 to over 2800 liters per square meter (L / m2) when tested at a flow rate of 1 gal / min / ft2. In an embodiment, filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 125 liters per square meter (L / m2) when tested at a flow rate of 1 gal / min / ft2. In yet another embodiment, the filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 400 liters per square meter (L / m2) when tested at a flow rate of 1 gal / min / ft2. In yet another embodiment, the filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 700 liters per square meter (L / m2) when tested at a flow rate of 1 gal / min / ft2. In yet another embodiment, the filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 1500 liters per square meter (L / m2) when tested at a flow rate of 1 gal / min / ft2In yet another embodiment, the filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 2000 liters per square meter (L / m2) w'hen tested at a flow rate of 1 gal / min / ft2. In yet another embodiment, the filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 2500 liters per square meter (L / m2) when tested at a flow rate of 1 gal / min / ft2In yet another embodiment, the filter media displays an ability to remove an amount of PFAS of greater than 80 wt% at 2800 liters per square meter (L / m2) w'hen tested at a flow rate of 1 gal / min / ft2.

[0086] The tests were run at 1 gal / min / ft2, with the test influent fluid adjusted to relied current levels of PFAS contamination across the USA.

[0087] PFAS removal was tested on samples of all of the above filter media, based on NSF 53 test standard. A 47 mm diameter disc was cut for each sample and tests were run at a flowrate of 1 gal / min / ft2, with the test influent fluid adjusted to reflect current levels of PFAS contamination across the USA. In particular, the test influent was adjusted to reflect the 95thpercentile of drinking water based on the most recent national survey (see Table 1 below for the influent concentrations).

[0088] The filter media achieves bacterial removal of at least 3-log (e.g., for the removal of bacteria and cysts) and virus removal of at least 2-log and preferably at least 3-log. The tests for bacteria and virus removal were conducted as follows. Three 25 mmP4477WO (AMJ0053PCT) samples were cut for each filter media and then placed in Millipore filter holders. The samples were then flushed with 40 mL of RO water (with conductivity adjusted to ~35pS / cm and pH adjusted to between 7.5 to 7.8). After the flush, the samples were challenged with approximately 50 mL of adjusted water that had been polluted with virus (MS2 at 1.25-1.75E5 pfu / mL), bacteria (Raoultella terrigena at 1.2E6-1.4E6cfu / mL), and cyst surrogate (Fluoresbrite™ Plain YG 3.0 Microspheres at 1 .25E5- 1 ,75E5beads / mL). Influent concentrations were measured after dilution by 1000. Effluent samples were then plated properly for each microorganism in order to provide filtration percentage for each.

[0089] The effluent was also diluted to 1000X (100 LI L of the challenge was added to 99 mL of phosphate buffered saline (with 1 mL of tryptic soy broth added to avoid lysis of the virus)).

[0090] To determine virus removal, effluent samples were plated using double layer agar method described in Kropinski AM, Mazzocco A, Waddell TE, Lingohr E, Johnson RP. Enumeration of bacteriophages by double agar overlay plaque assay. Methods Mol Biol. 2009;501 :69-76. Doi: 10. 1007 / 978- 1 -60327- 164-6_7. PMTD: 19066811. The total volume of effluent and agar was 8mL. Plates were allowed to dry, inverted, and then incubated for 17-19 hours at 37 C before viruses were counted.

[0091] To determine bacteria counts, diluted effluent was plated via a pipette on a 100mm tryptic soy agar plate. The cyst count in the effluent was determined by placing 0.1 mL of diluted effluent on a 8 mm microscope slide visualized under fluorescent microscope.

[0092] The filter media and its method of manufacture are exemplified by the following non-limiting example.EXAMPLEExample 1

[0093] This example was conducted to demonstrate the components used in the filter media and the method of manufacturing of the filter media.

[0094] All the examples below contain some of the following components. The examples were handsheets made in lab, using a handsheet mold to mimic the wet-laying machine process described above.P4477WO (AMJ0053PCT)

[0095] Adsorbent particles and other particles are added to a Labtech Standard Disintegrator Model 500-1. Fibrous material and binders are then added at dilution rate of approximately 10 g of pulp per 2000 mL water. For examples containing multiple binders, the positively charged binder is added first before any non-positively charged binders. The suspension is disintegrated for 10000 revolutions. The slurry is then added to an 8x8 inch Williams Apparatus handsheet mold. The suspension is then diluted further with water, agitated additionally by hand and drained onto a wire to form a fibrous web. The fibrous web is then removed from the wire by hand. Excess moisture is removed by pressing with blotting papers and the examples are subsequently dried on laboratory hot plate to form the example filter media. For the examples containing nanoalumina, the reaction components (Aluminium powder and 50% NaOH) are added after the fibers are added.Fibers: o Fibrillated Lyocell 1 : Lenzing 80°SR o Fibrillated Lyocell 2: EFT L040-6 o Cellulose Pulp: Alabama River Pine o PET Fibers: Trcvira T256 o Glass fibers 1: Lauscha B-06 o Glass fibers 2: Johns Manville 104-475 Adsorbents and other particles: o Activated Carbon: Jacobi WGA1 (powdered activated carbon) o Cyclodcxtrin: DEXSORB o Nano-alumina: formed from a reaction of aluminum powder and caustic (50% NaOH)Binders: o PAE-based positively charged binder (e.g., cationic binder 1): Solenis Polycup o PAE-based positively charged binder binder 2: Kymcnc 557H o Latex Binder (non-positively charged binder): Lubrizol (Hycar) 26450

[0096] Various compositions were manufactured and tested in order to determine which filter media compositions functioned best for the removal of PFAS. Viral and bacterial removal tests were also conducted. The compositions and the test results areP4477WO (AMJ0053PCT) shown in the Tables 2 and 3. The initial examples comprised filter media containing only one of the following functional additives, to understand the impact of each additive alone: Positively charged binder (c.g., cationic binder (Example 1)) activated carbon (Example 2) cyclodextrin (Example 3) nano-alumina particles (Example 4)

[0097] Additional examples were tested combining multiple functional additives: Activated Carbon + Nano-alumina (Example 5)Activated Carbon + Nano-alumina + cyclodextrin (Example 6)Activated Carbon + Positively charged binder (Cationic Binder (Examples 7a, 7b, 7c and 7d))Activated Carbon + Positively charged binder (Cationic Binder) + cyclodextrin (Example 8))

[0098] PF AS removal was tested on samples of all of the above filter media, based on NSF 53 test standard. A 47mm diameter disc was cut for each sample and tests were run at a flowrate of 1 gal / min / ft2, with the test influent fluid adjusted to reflect current levels of PF AS contamination across the USA. In particular, the test influent was adjusted to reflect the 95thpercentile of drinking water based on the most recent national survey (see Table 1 below for the influent concentrations). Additionally, the samples were also tested for virus, bacteria and cyst removal.P4477WO (AMJ0053PCT)Table 1

[0099] The performance of the examples for removal of various contaminants, including PF AS contaminants is shown below in Tables 2 and 3P4477WO (AMJ0053PCT)Table 2P4477WO (AMJ0053PCT)Table 3P4477WO (AMJ0053PCT)

[0100] From the Tables 2 and 3, it may be seen that the presence of the cationic binder (e.g., PAE binder) and an adsorbent (e.g., activated carbon) are useful in removing a higher percentage of PFAS from water, while also having cyst and bacteria removal.

[0101] From the Table 3 it may be seen that the activated carbon from Example 7b, which is an activated carbon with a high BET surface area of greater than 1000 m2 / g and an iodine number of greater than 1000 mg / g is also a catalytic carbon that produces the best results for PFAS removal.Example 3

[0101] An additional example was conducted with a composition similar’ to that in Example 7b (sec Tables 2 and 3), on a paper machine using the wet-laid process outlined above. Fibrillated lyocell (LENZING 80SR Lyocell), non-fibrillated cellulose pulp (Alabama River Pine and PET fibers (TREVIRA T256 binder fiber) were mixed together in a pulper in a paper machine along with water to form a fiber mixture. No refining is applied to the fiber mixtureA positively charged PAE binder was then added to the pulper. A non-positively charged latex binder was added after the addition of the positively charged PAE binder to form a slurry. The slurry and the constituents were allowed to mix together before the slurry was transferred to the headbox . A high-surface area activated carbon adsorbent (OXPURE Activated Carbon) was also added to the slurry at the headbox and the slurry was then further diluted.

[0102] The diluted slurry was applied onto a wire conveyor in a papermaking machine (e.g., a fourdrinier or a rotof ormer) to form the filter media. Vacuum was continuously applied during the aforementioned processes to remove the solvent from the mixture and / or the slurry, thereby producing a fibrous web. The web thus formed was subsequently dried to form the filter media and wound into a roll. The composition of the filter media is as follows, based on the weight of the media:Fibrillated Lyocell 1 - 34.2 wt%PET fibers - 14.6 wt%Cellulose Pulp - 9.8 wt%Activated Carbon (Puragen Oxpure) - 37.5 wt%PAE binder - 1 wt%Latex Binder - 2.9 wt%The properties of the filter media are shown in Table 4 below:P4477WO (AMJ0053PCT)Table 4P4477WO (AMJ0053PCT)[0103 J The filter media was laminated with a 25gsm PET spunbond layer, which serves as a mechanical support layer. The filter material was made into a cartridge filter and tested for PFAS removal using higher contaminant levels. Table 5 below shows the contaminant levels for the filter testing which are many-fold higher than the amounts used for handsheet tests since the filter cartridge has a larger filtration surface.Table 5[0104J Two filter cartridges were tested for PFAs removal and the average performance data is shown in the graph in FIG. 1. FIG. l is a graph that depicts percentage reduction in PFAS levels versus different volumetric flows in liters per square meter (L / m2). The total PFAS removal as well as the performance of specific short-chained and long-chained PFAS chemicals is shown in Table 6 below:P4477WO (AMJ0053PCT)Tabic 6

[0102] It is to be noted that the media, which contains 1 wt% cationic binder and a high- surface area activated carbon demonstrates a high PFAS removal at volumes well above 3000 L / m2, while also showing high cyst and bacteria removal.

[0103] In an embodiment, it is desirable to use at or over 0.5 wt%, preferably greater than or equal to 1 wt%, more preferably greater than or equal to 1.5 wt% of the cationic binder in conjunction with the activated carbon to obtain the best PFAS removal results.

[0104] In an embodiment, a filter media comprises cellulosic fibers; a positively charged binder; and adsorbent particles; where the filter media is operative to remove per- and polyfluoroalkyl moieties.

[0105] In another embodiment, the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 125 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of per- and polyfluoroalkyl moieties in the water.

[0106] In yet another embodiment, the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 400 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of per- and polyfluoroalkyl moieties in the water.

[0107] In yet another embodiment, the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 700 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of per- and polyfluoroalkyl moieties in the water.

[0108] In yet another embodiment, the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 2800 liters per square meter ofP4477WO (AMJ0053PCT) water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of pcr- and polylluoroalkyl moieties in the water.

[0109] In yet another embodiment, the cellulosic fibers comprise fibrillated fibers and / or non-fibrillated fibers.

[0110] In yet another embodiment, the filter media further comprises non-cellulosic fibers.

[0111] In yet another embodiment, the non-cellulosic fibers comprises synthetic polymer fibers and / or glass fibers.

[0112] In yet another embodiment, the adsorbent particles are selected from the group consisting of activated carbon, diatomaceous earth, silica, porous glass, zeolites, alumina, activated alumina, ion exchange resins, silica gel, molecular sieves, chitosan, rice husk, straw, crystalline materials such as ' -alumina, zirconia, cellulose nanocrystals (CNC), cyclic oligosaccharides such as cyclodextrin, titania, clay minerals, and a combination thereof.

[0113] In yet another embodiment, the adsorbent particle is activated carbon with a BET surface area of more than 900m2 / gm and / or an iodine number of greater than 700mg / grams.

[0114] In yet another embodiment, the adsorbent particles are present in an amount of up to 65 wt%, preferably from 15 to 60 wt%, more preferably 20 to 58 wt%, especially preferred 35 to 55 wt% based on a total weight of the filter media.

[0115] In yet another embodiment, the cationic binder comprises a polyamideepichlorohydrin copolymer, a polycthylcnciminc (PEI), a polyamidoaminc, a polylysinc, a poly(allylamine), a poly(diallyldimethylammonium chloride), a poly(N-isopropyl acrylamide -coacrylamide), a poly(N-isopropyl acrylamide-co-acrylic acid), a poly(L-lysine), a diethylaminoethyl-dextran copolymer, a poly-(N-ethyl-vinylpyridinium bromide), a poly(- dimethylamino)ethyl methacrylate), a poly(ethylene glycol)-co-poly(trimethylaminoethyl- mcthacrylatctrimcthylaminocthylmcthacrylatc chloride), an epichlorohydrin based polymer, a polyamide, an epichlorohydrin-dimethylamine copolymer, or a combination thereof.

[0116] In yet another embodiment, the positively charged binder comprises a polyamideepichlorohydrin copolymer.

[0117] In yet another embodiment, the filter media further comprising positively charged particles or fibers.

[0118] In yet another embodiment, the positively charged binder is present in an amount of greater than or equal to 0.5 wt%, preferably greater than or equal to 0.7%, and moreP4477WO (AMJ0053PCT) preferably greater than or equal to 1%, based on a total weight of the filter media when the filter media comprises positively charged particles.

[0119] In yet another embodiment, the positively charged binder is present in an amount of greater than or equal to 1 wt%, preferably greater than 1.25 wt%, preferably greater than 1.55 wt%, and more preferably greater than 2 wt%, based on a total weight of the filter media.

[0120] In yet another embodiment, the positively charged binder is present in an amount of 1 wt% to 5 wt%, based on a total weight of the filter media.

[0121] In yet another embodiment, the fibrillated fibers are present in an amount of 2 to 60 wt%, based on the total weight of the filter media.

[0122] In yet another embodiment, the non-flbrillated fibers are present in an amount of 2 to 75 wt%, based on the total weight of the filter media.

[0123] In yet another embodiment, the adsorbent particles are present in an amount of 15 to 60 wt%, based on the total weight of the filter media.

[0124] In yet another embodiment, the adsorbent particles are present in an amount of 20 to 55 wt%, based on the total weight of the filter media; and wherein the positively charged binder is pol amide-epichlorohydrin that is present in an amount of greater than or equal to 1 wt%, based on a total weight of the filter media.

[0125] In yet another embodiment, the filter media further comprises a non-positively charged binder.

[0126] In an embodiment, an article comprising the filter media of any one of the foregoing embodiments.

[0127] In an embodiment, a method of manufacturing a filter media, the method comprising blending together water, cellulosic fibers; non-cellulosic fibers; a positively charged binder; and adsorbent particles to form a slurry; where the positively charged binder is present in an amount of less than 5 wt%, where the cellulosic fibers arc present in an amount of up to 65 wt%, and where the positively charged binder is present in an amount of 1 to 5 wt%, based on a total weight of the filter media; transporting the slurry to a headbox of a paper-making machine; applying the slurry onto a wire conveyor in the papermaking machine to form a fibrous web media; and applying a continuous vacuum during the applying of the slurry onto the wire conveyor; and drying the fibrous web to manufacture the filter media.

[0128] In another embodiment, the adsorbent particles are present in an amount of up to 65 wt%, based on the total weight of the filter media.P4477WO (AMJ0053PCT)

[0129] In another embodiment, the adsorbent particles comprise activated carbon.

[0130] In an embodiment, the method comprises passing water to be filtered through a filter media of any one of the foregoing embodiments.

[0131] All ranges included herewith are inclusive of end points.

[0132] While the invention has been described with reference to some embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

P4477WO (AMJ0053PCT)CLAIMSWhat is claimed is:

1. A filter media comprising: cellulosic fibers; a positively charged binder; and adsorbent particles; where the filter media is operative to remove per- and polyfluoroalk l moieties.

2. The filter media of Claim 1, where the filter media is operative to remove per- and poly fluoroalkyl moieties in an amount of greater than 80 wt% at 125 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of pcr- and polyfluoroalkyl moieties in the water.

2. The filter media any one of the foregoing claims, where the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 400 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of per- and poly fluoroalkyl moieties in the water.

3. The filter media of any one of the foregoing claims, where the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 700 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of per- and poly fluoroalkyl moieties in the water.

4. The filter media of any one of the foregoing claims, where the filter media is operative to remove per- and polyfluoroalkyl moieties in an amount of greater than 80 wt% at 2800 liters per square meter of water when tested at a flow rate of greater than 0.5 gal / min / ft2, based on a total amount of per- and poly fluoroalkyl moieties in the water.

5. The filter media of any one of the foregoing claims, where the cellulosic fibers comprise fibrillated fibers and / or non-fibrillated fibers.P4477WO (AMJ0053PCT)6. The filter media of any one of the foregoing claims, where the filter media further comprises non-cellulosic fibers.

7. The filter media of any one of the foregoing claims, where the non-cellulosic fibers comprises synthetic polymer fibers and / or glass fibers.

8. The filter media of any one of the foregoing claims, where the adsorbent particles are selected from the group consisting of activated carbon, diatomaceous earth, silica, porous glass, zeolites, alumina, activated alumina, ion exchange resins, silica gel, molecular sieves, chitosan, rice husk, straw, crystalline materials such as y-alumina, zirconia, cellulose nanocrystals (CNC), cyclic oligosaccharides such as cyclodextrin, titania, clay minerals, and a combination thereof.

9. The filter media of any one of the foregoing claims, adsorbent particle is activated carbon with a BET surface area of more than 900m2 / gm and / or an iodine number of greater than 700mg / grams.

10. The filter media of any one of the foregoing claims, where the adsorbent particles are present in an amount of up to 65 wt%, preferably from 15 to 60 wt%, more preferably 20 to 58 wt%, especially preferred 35 to 55 wt% based on a total weight of the filter media.

11. The filter media of any one of the foregoing claims, where the cationic binder comprises a polyamide-epichlorohydrin copolymer, a polyethyleneimine (PEI), a polyamidoamine, a polylysine, a poly(allylamine), a poly(diallyldimethylammonium chloride), a poly(N-isopropyl acrylamide-co-acrylamide), a poly(N-isopropyl acrylamide-co-acrylic acid), a poly (L -lysine), a diethylaminoethyl-dextran copolymer, a poly-(N-ethyl-vinylpyridinium bromide), a poly(-dimethylamino)ethyl methacrylate), a polyfethylene glycol)-co- poly(trimethylaminoethylmethacrylatetrimethylaminoethylmethacrylate chloride), an epichlorohydrin based polymer, a polyamide, an epichlorohydrin-dimethylamine copolymer, or a combination thereof.P4477WO (AMJ0053PCT)12. The filter media of any one of the foregoing claims, where the positively charged binder comprises a polyamide-epichlorohydrin copolymer.

13. The filter media of any one of the foregoing claims, further comprising positively charged particles or fibers.

14. The filter media of any one of the foregoing claims, where the positively charged binder is present in an amount of greater than or equal to 0.5 wt%, preferably greater than 0.7%, and more preferably greater than 1%, based on a total weight of the filter media when the filter media comprises positively charged particles.

15. The filter media of any one of the foregoing claims, where the positively charged binder is present in an amount of greater than or equal to 1 wt%, preferably greater than 1.25 wt%, preferably greater than 1 .55 wt%, and more preferably greater than 2 wt%, based on a total weight of the filter media.

16. The filter media of any one of the foregoing claims, where the positively charged binder is present in an amount of greater than 1 wt% up to 5 wt%, based on a total weight of the filter media.

17. The filter media of any one of the foregoing claims, where the fibrillated fibers are present in an amount of 2 to 60 wt%, based on the total weight of the filter media.

18. The filter media of any one of the foregoing claims, where the non-fibrillated fibers arc present in an amount of 2 to 75 wt%, based on the total weight of the filter media.

19. The filter media of any one of the foregoing claims, where the adsorbent particles are present in an amount of 15 to 60 wt%, based on the total weight of the filter media.

20. The filter media of any one of the foregoing claims, where the adsorbent particles are present in an amount of 20 to 55 wt%, based on the total weight of the filter media; andP4477WO (AMJ0053PCT) wherein the positively charged binder is polyamidc-cpichlorohydrin that is present in an amount of greater than or equal to 1 wt%, based on a total weight of the filter media.

21. The filter media of any one of the foregoing claims, where the filter media further comprises a non-positively charged binder.

22. An article comprising the filter media of any one of the foregoing claims.

23. A method of manufacturing a filter media, the method comprising: blending together water, cellulosic fibers; non-cellulosic fibers; a positively charged binder; and adsorbent particles to form a slurry; where the positively charged binder is present in an amount of less than 5 wt%, where the cellulosic fibers are present in an amount of up to 65 wt%, and where the positively charged binder is present in an amount of 1 to 5 wt%, based on a total weight of the filter media; transporting the slurry to a headbox of a paper-making machine; applying the slurry onto a wire conveyor in the papermaking machine to form a fibrous web media; and applying a continuous vacuum during the applying of the slurry onto the wire conveyor; and drying the fibrous web to manufacture the filter media.

24. The method of Claim 17, where the adsorbent particles are present in an amount of up to 65 wt%, based on the total weight of the filter media.

25. The method of any one of the foregoing claims, where the adsorbent particles comprise activated carbon.

26. A method of filtering water, the method comprising passing water to be filtered through a filter media of any one of the Claims 1 to 21 or an article of Claim 22.

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