Acid washing

Abstract

Adsorbent materials comprising a carbonaceous material activated to form a precursor activated carbon, which is subjected to an acid or base pretreatment and then optionally thermal oxidation, are useful for treating water. The adsorbent material is produced by contacting the precursor activated carbon with a nitrogen source and a metal source, and optionally thermally oxidizing the precursor activated carbon. The resulting loaded precursor activated carbon is also calcined.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 482,461, filed January 31, 2023, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE DISCLOSURE This disclosure relates generally to activated carbon for water treatment. More specifically, this disclosure relates to compositions and methods for producing activated carbon with high efficacy for removing specific contaminants, and methods of using the same. [Background technology]

[0003] The use of adsorbents for water treatment has been established as an effective method for removing various contaminants from water sources. Adsorbents with different properties can be selected to selectively remove specific contaminants, allowing for the development of a wide range of water treatment systems. Of particular interest is the removal of harmful regulated contaminants such as chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, and peroxides. These contaminants not only pose a health hazard, but can also alter the odor and taste of drinking water and cause corrosion and deterioration of water pipes.

[0004] Previous strategies for the removal of chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, and peroxides have focused on treating activated carbon adsorbent materials with nitrogen addition or thermal calcination to functionalize the adsorbent structure with nitrogen end groups to improve chloramine and chlorine removal performance. Chemical oxidation treatment of adsorbent materials prior to nitrogen addition has also proven effective in enhancing chloramine and peroxide removal properties.

[0005] However, these methods are targeted at coal-based activated carbon raw materials, and achieving this performance improvement with coconut-based or wood-based activated carbons is more difficult. Coconut-based activated carbon, in particular, inherently offers the advantage of volatile organic compound (VOC) removal. Therefore, it is highly desirable to combine the high VOC removal performance of coconut-based activated carbon with the improved removal performance of chloramines, chlorine, and peroxides to provide a dual-use adsorbent material.

[0006] At the same time, there remains a need not only to apply the above-mentioned techniques to coconut-based activated carbon, but also to further improve coal-based activated carbon. Summary of the Invention

[0007] In some embodiments, the technology described herein provides a carbonaceous material that is activated to form a precursor activated carbon, where the precursor activated carbon is subjected to an acid or base pretreatment and then optionally thermally oxidized, and the precursor activated carbon is contacted with a nitrogen source and a metal source, and contains about 5% to about 12% nitrogen and about 0.1 wt % to about 1.0 wt % metal, measured on a dry precursor activated carbon basis.

[0008] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having a modified contact pH of about 3 to about 11.

[0009] In some aspects, the technology described herein relates to adsorbent materials, wherein the pretreatment is an acid.

[0010] In some aspects, the technology described herein relates to adsorbent materials, wherein the acid is any of nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, acetic acid, citric acid, ascorbic acid, or combinations thereof.

[0011] In some embodiments, the technology described herein relates to adsorbent materials, wherein the adsorbent materials have a modified contact pH of about 5 to about 8.

[0012] In some embodiments, the technology described herein relates to adsorbent materials, wherein the pretreatment is with a base.

[0013] In some embodiments, the technology described herein relates to adsorbent materials, wherein the base is any of sodium hydroxide, ammonium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, or combinations thereof.

[0014] In some embodiments, the technology described herein relates to adsorbent materials, wherein the adsorbent materials have a modified contact pH of about 7 to about 11.

[0015] In some aspects, the technology described herein relates to an adsorbent material, wherein the metal is selected from iron, copper, zinc, or a combination thereof.

[0016] In some embodiments, the technology described herein relates to a sorbent material, wherein the carbonaceous material is formed from one or more of coconut shell, bituminous coal, sub-bituminous coal, lignite, or anthracite.

[0017] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having a Chloramine Destruction Number (CDN) of about 10 to about 75.

[0018] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having a Chloramine Destruction Number (CDN) of about 37 to about 72.

[0019] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having a peroxide value of about 1.5 minutes to about 40 minutes.

[0020] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having a peroxide value of about 2.6 minutes to about 3.7 minutes.

[0021] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having an oxygen content of about 3% to about 9%.

[0022] In some embodiments, the technology described herein relates to a method for producing an adsorbent material, comprising the steps of providing a carbonaceous material; activating the carbonaceous material to form a precursor activated carbon; pretreating the precursor activated carbon with an acid or base; optionally thermally oxidizing the precursor activated carbon at a temperature of about 450°C; contacting the precursor activated carbon with a metal source and a nitrogen source to form a loaded precursor activated carbon; and calcining the loaded precursor activated carbon at a temperature of about 950°C.

[0023] In some embodiments, the technology described herein relates to a method, wherein the carbonaceous material is formed from one or more of coconut shells, bituminous coal, sub-bituminous coal, lignite, or anthracite.

[0024] In some embodiments, the technology described herein relates to a method, wherein the acid is any of nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, acetic acid, citric acid, ascorbic acid, or a combination thereof.

[0025] In some embodiments, the technology described herein relates to a method, wherein the base is any of ammonium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, or a combination thereof.

[0026] In some embodiments, the technology described herein relates to a method, wherein the metal source is any of copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) hydroxide carbonate, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof.

[0027] In some embodiments, the technology described herein relates to methods, wherein the nitrogen source has an oxidation state of −3.

[0028] In some aspects, the technology described herein relates to methods, wherein the nitrogen source comprises urea, dicyandiamide, melamine, or a combination thereof.

[0029] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a modified contact pH of about 5 to about 11.

[0030] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a chloramine destruction number (CDN) of about 10 to about 75.

[0031] In some embodiments, the technology described herein relates to adsorbent materials, the adsorbent materials having a Chloramine Destruction Number (CDN) of about 37 to about 72.

[0032] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a peroxide value of from about 1.5 minutes to about 40 minutes.

[0033] In some embodiments, the technology described herein relates to a method, wherein the adsorbent material has a peroxide value of about 2.6 minutes to about 3.7 minutes.

[0034] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has between about 3% and about 9% oxygen.

[0035] In some embodiments, the technology described herein relates to a method for treating water potentially containing chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, volatile organic compounds, or combinations thereof, comprising contacting the water with a sorbent material comprising activated carbon formed from a carbonaceous material, wherein the activated carbon is pretreated with an acid or a base, then thermally oxidized, and then added with a metal source and a nitrogen source; and wherein contacting the water with the sorbent material removes one or more of the chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, and volatile organic compounds.

[0036] In some embodiments, the technology described herein relates to a method, wherein the carbonaceous material is one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, or coconut shell.

[0037] In some embodiments, the technology described herein relates to a method, wherein the metal source is any of copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) carbonate hydroxide, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof.

[0038] In some embodiments, the technology described herein relates to methods, wherein the nitrogen source has an oxidation state of −3.

[0039] In some aspects, the technology described herein relates to methods, wherein the nitrogen source comprises urea, dicyandiamide, melamine, or a combination thereof.

[0040] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a modified contact pH of about 3 to about 11.

[0041] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a chloramine destruction number (CDN) of about 10 to about 75.

[0042] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a Chloramine Destruction Number (CDN) of about 37 to about 72.

[0043] In some embodiments, the technology described herein relates to methods, wherein the adsorbent material has a peroxide value of from about 1.5 minutes to about 40 minutes.

[0044] In some embodiments, the technology described herein relates to a method, wherein the adsorbent material has a peroxide value of about 2.6 minutes to about 3.7 minutes.

[0045] In some embodiments, the technology described herein relates to methods wherein the adsorbent material has an oxygen content of about 3% to about 9%. [Brief explanation of the drawings]

[0046] [Figure 1] FIG. 1 is a graph showing the relationship of modified contact pH between the resulting chloramine destruction number (CDN) and peroxide number for activated carbons spiked with copper-iron and urea. [Figure 2] FIG. 2 is a graph showing the relationship between changing contact pH and the resulting chloramine destruction number (CDN) and peroxide value for activated carbon doped with iron and urea. [Figure 3] FIG. 3 is a graph showing the relationship between modified contact pH and the resulting chloramine destruction number (CDN) and peroxide value for activated carbon spiked with copper and urea. [Figure 4] FIG. 4 is a graph of ash level versus modified contact pH, showing that there is little correlation between the modified contact pH and ash level of activated carbon. DETAILED DESCRIPTION OF THE INVENTION

[0047] The present disclosure is not limited to the particular systems, devices, and methods described, and the terminology used herein is for the purpose of describing particular versions or embodiments only, and is not intended to limit the scope.

[0048] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nothing in this disclosure should be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used herein, the term "comprising" means "including, but not limited to."

[0049] As used herein, the term "about" means plus or minus 10% of the numerical value with which it is used. For example, "about 50%" means a range of 45 to 55%.

[0050] As used herein, the term "adsorbent material" refers to any material that exhibits adsorption, absorption, or a combination of adsorption and absorption properties. Adsorption refers to the attachment of atoms, ions, or molecules to the surface of the material. Adsorption refers to the insertion and retention of atoms, ions, or molecules into the bulk phase of the material. Exemplary adsorbent materials include, but are not limited to, activated carbon, reactivated carbon, natural and synthetic zeolites, silica, silica gel, alumina, zirconia, and diatomaceous earth. As used herein, an "adsorbent material" refers to a material whose constituent components are substantially adsorbent and / or absorbent and have only minimal components that are not adsorbent and / or absorbent (e.g., the minimum amount of binder required for activated carbon pellets to maintain their shape).

[0051] As used herein, the term "sorbent" refers to any composition or composite that includes a sorbent material in a blend, mixture, composite, or compound with one or more additional materials that do not exhibit sorbent properties. As an example, one embodiment of a sorbent includes an activated carbon sorbent material mixed with a thermally conductive filler.

[0052] As used herein, the term "carbonaceous material" refers to a material containing carbon that has not been thermally or chemically activated. Carbonaceous materials may be mechanically, thermally, or chemically treated and may have weak adsorption properties, but do not adsorb substantial amounts of compounds as would be expected from a material such as activated carbon. Examples of carbonaceous materials include, but are not limited to, bituminous coal, subbituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, pits, coconut shells, babassu nuts, macadamia nuts, dende nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitch, bagasse, rice husks, corn husks, wheat husks, and rice husks, graphene, carbon nanotubes, or polymer fibers.

[0053] As used herein, the term "macropores" refers to pores within the adsorbent that are greater than about 50 nm in diameter.

[0054] As used herein, the term "mesopores" refers to pores within an adsorbent having diameters of about 2 nm to about 50 nm.

[0055] As used herein, the term "micropore" means a pore within an adsorbent having a diameter of less than about 2 nm.

[0056] As used herein, "chloramine" means one or more of monochloramine (NH2Cl), dichloramine (NHCl2), or trichloramine (NCl3).

[0057] The adsorbents or adsorbent materials described herein are useful for removing chloroform and other similar volatile organic chemical compounds (VOCs) from fluids such as water, including, but not limited to, styrene, alachlor, atrazine, benzene, carbofuran, carbon tetrachloride, chlorobenzene, chloropicrin, 2,4-dichlorophenoxyacetic acid (2,4-D), dibromochloropropane (DBCP), o-dichlorobenzene, p-dichlorobenzene, 1,2-dichloroethane, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, 1,2-dichloropropane, cis-1,3-dichloropropylene, dinoseb, endrin, ethylbenzene, ethylene dibromide (EDB), bromochloroacetonitrile, dibromoacetonitrile, haloacetonitriles (HANs) including dichloroacetonitrile, trichloroacetonitrile, 1,1-di ... Contains one or more of the following trihalomethanes: haloketones (HK) including chloro-2-propanone, 1,1,1-trichloro-2-propanone, heptachlor (H-34, Heptox), heptachlor epoxide, hexachlorobutadiene, hexachlorocyclopentadiene, lindane, methoxychlor, pentachlorophenol, simazine, styrene, 1,1,2,2-tetrachloroethane, tetrachloroethylene, toluene, 2,4,5-TP (Silvex), tribromoacetic acid, 1,2,4-trichlorobenzene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, bromoform, bromodichloromethane, chlorodibromomethane, or xylene. Relevant VOCs in the drinking water field are known in the art and are described, for example, in NSF / ANSI 53-2019, designated a standard on May 6, 2019, which is incorporated by reference in its entirety. In some embodiments, VOC removal by an adsorbent or adsorbent material is measured by the removal of the individual VOC species themselves. In other embodiments, VOC removal by an adsorbent or adsorbent material is measured by the removal of a surrogate compound. A surrogate compound is a compound that is similar in chemical composition to the analyte and is present in the sample prior to preparation and analysis. For example, chloroform is an example of a surrogate for the compounds in this section.

[0058] This disclosure describes examples of processing sorbent materials that result in unique pollutant removal properties. Specifically, the sorbent materials are activated carbons formed from various precursors that are processed with various processing methods to improve pollutant removal performance.

[0059] The present disclosure describes a method for preparing a sorbent material that involves treating activated carbon with an acid or base, followed by optional thermal oxidation, and then adding metals and nitrogen to improve chloramine, chlorine, and peroxide removal properties. Without wishing to be bound by theory, the disclosed method is particularly advantageous for use with coconut-based and wood-based activated carbons, instead of coal-based activated carbons, to which previous methods are directed.

[0060] According to some embodiments of the present disclosure, one or more carbonaceous materials are provided and activated by any suitable technique to obtain a precursor activated carbon. The precursor activated carbon is then washed with an acid or base to obtain a washed activated carbon. The washed activated carbon is then optionally heat-treated to obtain a pre-loaded precursor activated carbon. In some embodiments, the heat-treatment can include drying, thermal oxidation, or a combination thereof. The pre-loaded precursor activated carbon is then loaded with metal and nitrogen to obtain a loaded precursor activated carbon, which is then calcined to obtain a metal- and nitrogen-loaded activated carbon according to the disclosure herein.

[0061] Prior disclosures describing methods of doping precursor activated carbon include U.S. Patent No. 10,702,853, U.S. Provisional Application No. 63 / 072,531, entitled "Copper and Nitrogen Treated Sorbents and Methods for Making Same," U.S. Patent Application Publication No. 2022 / 0062861, which claims priority to U.S. Provisional Application No. 63 / 072,544, entitled "Copper, Iron, and Nitrogen Treated Sorbents and Methods for Making Same," and U.S. Patent Application Publication No. 2022 / 0062855, which claims priority to U.S. Provisional Application No. 63 / 072,514, entitled "Copper and Nitrogen Treated Sorbents and Methods for Making Same," each of which is incorporated herein by reference in its entirety. This disclosure demonstrates that acid / base washing of activated carbon and optional heat treatment of the acid / base washed activated carbon prior to doping with metal / nitrogen results in a doped activated carbon with improved chloramine, chlorine, and peroxide removal properties. The disclosed treatment is particularly useful with coconut shell activated carbon, as it has been difficult to impart chloramine-destroying properties to coconut shell activated carbon using conventional treatment techniques.

[0062] It has previously been reported that metal-nitrogen doping of coconut-based activated carbon can be used to enhance chloramine destruction performance. The present disclosure provides, but is not limited to, a method for pretreating activated carbon, such as coconut-based or coal-based activated carbon, to further improve chloramine and peroxide destruction performance by first washing the precursor activated carbon with an acid or base to obtain a washed precursor activated carbon, and then, optionally, thermally oxidizing the washed precursor activated carbon. Following the washing and optional thermal oxidation steps, metal-nitrogen doping to provide the doped activated carbon improves chloramine, chlorine, and peroxide removal properties compared to untreated activated carbon. It has also been demonstrated herein that further improvements are observed when the acid or base washing step is performed first and the thermal oxidation step is performed second. When both are employed in this order, the resulting adsorbent material has superior performance characteristics. By pretreating virgin coconut activated carbon or virgin coal activated carbon to alter its modified contact pH and oxygen concentration, the most effective chloramine and peroxide destruction performance can be achieved.

[0063] One or more carbonaceous materials are provided as precursors to the final adsorbent. These carbonaceous materials may be mechanically, thermally, or chemically treated prior to activation to produce activated carbon. As will be appreciated by those skilled in the art, activated carbon can be prepared from a variety of materials, including bituminous coal, subbituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, pits, coconut shells, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitch, bagasse, rice husks, corn husks, wheat husks, and rice husks, graphene, carbon nanotubes, and polymer fibers. Because each of these materials can impart different properties to the resulting adsorbent material, it may be advantageous to select activated carbon formed from a specific carbonaceous material depending on the purpose for which the activated carbon will be used.

[0064] In some embodiments, the carbonaceous material is coconut shell. Coconut shell carbonaceous materials are particularly useful because, when activated, coconut shells exhibit superior adsorption of chloroform and other organic compounds compared to activated carbons formed from other starting materials. Because of their highly developed microporous structure, coconut shell-based activated carbons inherently remove VOCs to a higher degree than coal-based activated carbons. By using treatment methods to enhance the specific performance of coconut-based activated carbons, both the inherent properties of coconut-based activated carbon and the benefits of specific treatment methods can be utilized. Such "dual-use" carbons are particularly useful in applications where removal of multiple contaminants is desired.

[0065] In some other embodiments, the carbonaceous material is coal, including, but not limited to, one or more of bituminous coal, subbituminous coal, lignite, or anthracite.

[0066] After the carbonaceous material is provided, it is activated. The method used to activate the carbon before carrying out the methods of the present disclosure is not particularly limited. In some embodiments, the carbonaceous material may be activated by a thermal method, and in some embodiments, the carbonaceous material may be activated by a chemical method. The activation process depends on the type of carbonaceous material utilized and the desired form of the final activated carbon. The activation process can include one or more of the following steps: pyrolyzing the carbonaceous material to form charcoal; crushing the charcoal; mixing the crushed charcoal with a binder; briquetting the crushed charcoal and binder; crushing the briquettes; sizing the crushed briquettes; and firing the sized briquettes or the briquettes themselves to carbonize, harden, or remove the binder. In any case, however, the carbonaceous material is thermally activated, chemically activated, or thermally and chemically activated. Thermal activation is carried out by heating the fired briquettes or sized particles in the presence of one or more of water, oxygen, and carbon dioxide. Chemical activation is accomplished by impregnating fired briquettes or sized particles in the presence of a strong acid, strong base, or salt. It should be noted that whether each of the above steps is included in the process may vary depending on the carbonaceous material provided. For example, if the carbonaceous material is coconut, the process steps do not include "reagglomeration," which are mixing pulverized coal with a binder, briquetting the pulverized coal and binder, crushing the briquettes, and sizing the crushed briquettes. In some embodiments of the present disclosure, a precursor activated carbon is obtained by activating the carbonaceous material.

[0067] The precursor activated carbon is then treated according to embodiments of the present disclosure. In some embodiments, pretreating the precursor activated carbon may include washing the precursor activated carbon with an acid or base, heat-treating the precursor activated carbon, and / or doping the precursor activated carbon with a metal and nitrogen. In some embodiments, the pretreatment steps can be performed in the order of washing, heat-treating, and doping. In some embodiments, the steps may be performed in the order of heat-treating, washing, and doping. In some embodiments, the washing step may be omitted, and the method may include heat-treating and doping. In some embodiments, the thermally treating step may be omitted, and the method may include washing and doping. Performing the treatment steps in the order of washing, heat-treating, and doping has been found to improve performance compared to performing the treatment steps in a different order. In the above embodiments, heat-treating the precursor activated carbon may include a drying step, thermal oxidation, or a combination thereof.

[0068] In some embodiments, the washing step can be performed with hydrochloric acid, sulfuric acid, nitric acid, citric acid, ascorbic acid, ammonium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, or sodium bicarbonate, or a combination thereof. The precursor activated carbon can be washed in an acid or base solution at a concentration of about 0.1 M to about 0.5 M, for example, about 0.1 M, about 0.2 M, about 0.3 M, about 0.4 M, about 0.5 M, or any range between these values, for about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, or any range between these values. The washing step can include agitating the precursor activated carbon and / or subsequent washing with water. In some embodiments, the washing step can be performed before any other step of the disclosed method. In some embodiments, the washing step can be performed after any other step of the disclosed method.

[0069] In some embodiments, the heat treatment step may be performed at about 300°C to about 600°C, e.g., about 300°C, about 350°C, about 400°C, about 450°C, about 500°C, about 550°C, about 600°C, or within a range between any two such values. The time for the heat treatment step may be about 10 minutes, about 20 minutes, about 30 minutes, about 1 hour, about 2 hours, or any value or range between any two values. In some embodiments, the heat treatment step may be performed after the cleaning step. In some embodiments, the heat treatment step may be performed before the cleaning step. In some embodiments, the heat treatment step may be omitted. In some embodiments, the heat treatment step includes drying, thermal oxidation, or a combination thereof.

[0070] In some embodiments, the loading step may include impregnating the washed and / or heat-treated activated carbon with a metal and nitrogen source. The loading step may include contacting the washed and / or heat-treated activated carbon with an aqueous solution of a metal salt and a nitrogen-containing compound. In some embodiments, the metal salt is copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) hydroxide carbonate, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof. In some embodiments, the nitrogen-containing compound is urea, dicyandiamide, melamine, or other nitrogen-containing compounds having an oxidation state of −3. Loaded activated carbon can be formed by contacting the washed and / or heat-treated activated carbon with the metal and nitrogen solution. After contact, the loaded activated carbon can be dried in air or under an inert atmosphere at a temperature above room temperature. In some embodiments, the loaded activated carbon is dried at a temperature of about 50°C, about 60°C, about 70°C, about 80°C, about 90°C, about 100°C, about 110°C, about 120°C, about 130°C, about 140°C, about 150°C, about 160°C, about 170°C, about 180°C, about 190°C, about 200°C, or a temperature within a range between any two such values.

[0071] The added activated carbon can be evaluated by metal loading on a dry carbon basis. In some embodiments, the metal loading is about 0.10 wt%, about 0.15 wt%, about 0.20 wt%, about 0.25 wt%, about 0.30 wt%, about 0.35 wt%, about 0.40 wt%, about 0.45 wt%, about 0.50 wt%, about 0.55 wt%, about 0.60 wt%, about 0.65 wt%, about 0.70 wt%, about 0.75 wt%, about 0.80 wt%, about 0.85 wt%, about 0.90 wt%, about 0.95 wt%, about 1.0 wt%, or within a range between these values. The added activated carbon can be further characterized by the concentration of nitrogen provided by the nitrogen source on a dry carbon basis. In some embodiments, the concentration of nitrogen is about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, or within a range between any two values.

[0072] The loaded activated carbon may be calcined after drying. In some embodiments, the calcination is carried out at a temperature of about 750°C, about 800°C, about 850°C, about 900°C, about 950°C, about 1000°C, about 1050°C, about 1100°C, about 1150°C, about 1200°C, or within a range between any two values. In some embodiments, the calcination can be carried out under an inert atmosphere, such as nitrogen. Any of the aforementioned washing, heat treating, loading, and calcining steps can be carried out alone or in combination to form the adsorbent material.

[0073] In some embodiments, the sorbent materials of the present disclosure can be evaluated in terms of performance. In some embodiments, measuring the performance of a sorbent material can include measuring the chloramine destruction number, or CDN, according to Calgon Carbon Test Method 39 (TM-39). In some embodiments, measuring the performance of a sorbent material can include a peroxide destruction test, measured by the peroxide number determined by Calgon Carbon Test Method 25 (TM-25). In some embodiments, measuring the performance of a sorbent material can include measuring both the chloramine destruction number and the peroxide number. In some embodiments, the CDN of a sorbent material can be from about 10 to about 75, e.g., about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, or any value or range between any two such values. In some embodiments, the peroxide number is about 1.5 minutes to about 40 minutes, or about 2 minutes to about 40 minutes, e.g., about 1.5 minutes, about 2 minutes, about 5 minutes, about 10 minutes, about 15 minutes, about 20 minutes, about 25 minutes, about 30 minutes, about 35 minutes, about 40 minutes, or any value or range between any two such values. In some embodiments, the adsorbent material has a modified contact pH of about 3 to about 11, e.g., about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, or any value or range between any two values. In some embodiments, the adsorbent material has an oxygen content of about 3% to about 9%, e.g., about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or any value or range between any two values. The oxygen content or concentration described in this paragraph and throughout this specification is determined by elemental analysis.

[0074] In some embodiments, the sorbent material may be a "dual-purpose" sorbent material, such that it can remove volatile organic compounds while simultaneously removing one or more of chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, and peroxides. In some embodiments, the sorbent material may be capable of removing one or more of chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, and volatile organic compounds from a water source. [Example]

[0075] Two commercially available coconut feedstocks were used: one was a commercially available 12x40 non-acid-washed coconut-based activated carbon (OLC) and the other was a commercially available 12x40 acid-washed coconut-based activated carbon (OLC-AW). In one embodiment, the OLC or OLC-AW feedstock was thermally oxidized in air at 450°C for 1 hour at 1 liter per minute of air before loading with the metal salt / urea aqueous solution. The total metal loading was about 0.25 wt% to about 0.50 wt% based on dry carbon before calcination. The nitrogen concentration from urea was about 9 wt% based on dry carbon before calcination. After loading, the samples were dried in air at about 100°C to about 150°C for up to 2 hours and then calcined in nitrogen at 950°C for 1 hour. The calcined samples were then cooled in nitrogen before determining their chloramine destruction performance, as measured by the Chloramine Destruction Number (CDN) test by Calgon Carbon Test Method 39 (TM-39) or the Peroxide Destruction Test by the Peroxide Number test by Calgon Carbon Test Method 25 (TM-25). A higher CDN number indicates more aggressive and faster chloramine destruction, while a lower peroxide number indicates more aggressive and faster peroxide destruction. TM-39 and TM-25 ratings are volumetric, meaning that a fixed amount of carbon is evaluated to avoid variability in test results due to differences in carbon density.

[0076] Table 1 shows the improvement in chloramine destruction numbers (higher values ​​are desirable) and peroxide numbers (lower values ​​are desirable) when both acid wash and thermal oxidation pretreatments are employed. This effect is observed for all metal-nitrogen chemistries employed. Without either pretreatment, CDN values ​​ranged from 3.6 to 5.2, and peroxide values ​​ranged from 54.2 to 97.8 min. When only either acid wash or thermal oxidation pretreatment was employed, CDN values ​​ranged from 4.2 to 14.5, and peroxide values ​​ranged from 16.9 to 90.9 min, resulting in slight improvements. When both acid wash and thermal oxidation were used, CDN values ​​ranged from 11.7 to 72.2, and peroxide values ​​ranged from 2.6 to 23.5 min. Therefore, the best chloramine and peroxide destruction behavior occurred only when both acid wash and thermal oxidation were employed as pretreatment steps prior to metal salt / nitrogen addition and subsequent calcination. However, in Example 2, simply acid washing virgin activated carbon and impregnating it with copper-iron-nitrogen chemistry significantly improved the CDN value to 14.5. With this chemistry, acid washing alone was sufficient to achieve an intermediate CDN value. [Table 1] TIFF2026505056000003.tif84130

[0077] As shown in Table 2, the order in which the pretreatment steps are performed also affects the resulting CDN and peroxide value. Performing the acid wash first before thermal oxidation is crucial to imparting the superior performance observed with these activated carbons. The importance of this pretreatment order is evident when comparing Examples 13 and 14, where the CDN improved from 24.0 to 66.3 min and the peroxide value decreased from 8.3 min to 3.7 min. A similar improvement in CDN and decrease in peroxide value is evident when comparing Examples 15 and 16, where the acid wash step was performed before thermal oxidation. Example 15 had a CDN value of 47.0 and a peroxide value of 3.3 min, while Example 16 had a CDN value of 13.1 and a peroxide value of 19.7 min. Again, Examples 13, 15, and 17 benefited from performing the acid wash step before the thermal oxidation step, and this benefit was observed for all metal-nitrogen loaded chemistries. Throughout Table 2, the modified contact pH was lower for samples acid washed before thermal oxidation, suggesting a more acidic activated carbon surface. The more acidic nature of these carbons led to a more effective final product after addition and decarboxylation, as evidenced by increased CDN numbers and decreased peroxide numbers. Modification contact pH was measured using the Calgon Carbon Test Method 70 (TM-70) described herein.

[0078] TM-70-denatured contact pH Before starting to measure the modified contact pH, the following equipment and reagents were obtained: pH meter (any model with temperature compensation will do) Combination electrode (polymer or glass combination pH electrode with temperature compensation. The electrode must be of high quality and have a fast response time. If the pH of the sample is expected to be above 9 and Na + For high ionic concentrations (Na2SO4 buffers), special "high pH" electrodes are recommended). Glass measuring cylinder (TD100mL) Filter paper (pre-folded E&D Grade 513 or equivalent, 18.5 cm or equivalent) Funnel (stemless Pyrex top, 100mm inner diameter or equivalent) Glass beakers (400mL and 100mL) Glass volumetric flask (1L) Magnetic stirrers and stir bars Sodium sulfate (anhydrous, Na2SO4, formula weight 142.04) ·Sulfate solution (80ppm) In a clean volumetric flask, add 0.12 g of Na2SO4 to 800 mL of Type I reagent water to make a 1 liter solution. Shake to dissolve and dilute to volume with reagent water. The pH of the solution should be 6.0 qt 0.5. If not, check the purity of the reagent water. Type I Reagent Water Deionized water, preferably distilled from a Mill-Q Plus water purification system or equivalent (see Standard Methods for the Examination of Water and Wastewater for definition). ·Calibration buffer To calibrate a pH meter under standard conditions, commercially available buffer solutions of pH 4, pH 7, and pH 10 are used. For pH > 9, a pH 11 calibration buffer solution is also recommended.

[0079] The modified contact pH was determined according to the following procedure: A. Proofreading 1. Due to the wide variety of pH meters and accessories, detailed operating procedures cannot be incorporated into this method. Always calibrate your pH meter before use. At a minimum, we recommend calibrating it daily or at the start of each work shift. If the electrode appears damaged or has a slow response time, replace it. 2. Calibrate the system using calibration buffers at a minimum of two points that match the expected pH of the sample and are at least approximately 3 pH units apart. pH 7 and pH 10 buffers are appropriate for most carbon samples. If the contact pH of the product is estimated to be >9, the use of a special "high pH" electrode is recommended. pH 11 buffer should also be used for calibration. 3. Place the calibration buffer into a clean, dry 100 mL beaker, using enough to cover the electrode's sensing element. Stir gently and take a reading after 1 minute. Read the pH. Repeat. If the pH value remains the same, calibrate the meter. Adjust as necessary. 4. Repeat the adjustment with successive portions of the two (low-high) calibration buffers until the reading is within 0.1 pH units of the buffer value. Periodically measure the calibration buffers to ensure the meter remains calibrated. B. Contact pH Measurement 1. Weigh a representative portion of the granular activated carbon sample into a 400 mL beaker: pH type carbon (wet carbon) - 40.0g Standard carbon (dry carbon) - 25.0g Do not let the sample dry out. pH-type carbons typically contain a lot of moisture. The small amount of moisture (less than 2%) typically found in standard carbons is not a problem. Add 100 mL of the 280 ppm sulfate solution to the carbon sample. Check the pH of the sulfuric acid solution before use. If the pH is not 6.0 ± 0.5, prepare a fresh solution. 2. Add a magnetic stir bar and stir the mixture slowly for 30 minutes ± 1 minute. Avoid introducing air bubbles into the mixture. 3. Gravity filter the mixture through filter paper to remove the carbon particles. The filtrate is collected for pH measurement. The carbon particles will adhere to the pH electrode, preventing accurate pH measurements and ultimately destroying the electrode. 4. Place the electrode in the filtrate, stir gently for about 1 minute, and take a reading. Stir again for about 30 seconds and read the pH again. If the value is nearly the same (40.1), report this pH value as the "corrected" contact pH. If the pH value increases after the second stirring, it means the electrode has a slow response time. Continue stirring and reading until the pH value no longer increases. If more than 30 seconds are required, consider replacing the electrode. The porous glass tip may be clogged with carbon fines. [Table 2]

[0080] Table 3 shows the effect of acid or base washing followed by thermal oxidation on the modified contact pH of activated carbons before metal-nitrogen loading and calcination. The modified contact pH of activated carbons can be reduced to values ​​below 7.0 by first washing with mineral acids (nitric acid, hydrochloric acid, sulfuric acid) and then thermally oxidizing in air. These activated carbons, when loaded and calcined, achieve the highest CDN values, as shown in Examples 19-21. It is important to note that in Examples 19-21, similar modified contact pH values ​​are achieved using any of these mineral acids, since they all have similar modified contact pH values ​​(~5.7-6.2) after thermal oxidation.

[0081] The general importance of acid washing prior to thermal oxidation is further demonstrated in Table 3, where improvements in CDN are observed whether using a known oxidizing acid such as nitric acid (Example 21), a less oxidizing acid such as sulfuric acid (Example 20), a nonoxidizing mineral acid such as hydrochloric acid (Example 19), or a weak acid such as acetic acid (Example 22) or citric acid (Example 23). Improvements over the unwashed OLC (Example 26) precursor are also observed when a base such as ammonium hydroxide (Example 24) or sodium hydroxide (Example 25) is used in the initial pretreatment step. This data demonstrates that modifying the carbon surface using an acid or base treatment in combination with thermal oxidation improves the chloramine performance of the final product. Figures 1-3 show the trends of increased CDN and decreased peroxide numbers for each of the three additive chemistries listed in Table 3: Cu-Fe-N, Fe-N, and Cu-N. [Table 3] TIFF2026505056000006.tif113122

[0082] Table 4 shows the correlation between the contact pH of pretreated OLC activated carbon and the bulk oxygen content measured by elemental analysis. Generally, the higher the oxygen content, the lower the contact pH. As a result, pretreated activated carbons with lower contact pHs produce end products (post-treatment) with higher CDN values ​​and lower peroxide values, as shown in Table 3 and Figures 1-3. The highly oxygenated activated carbon feedstock obtained from the wash / thermal oxidation pretreatment was found to be important for achieving the superior performance obtained by pretreating first with an acid wash and then with thermal oxidation. It should also be noted that, as shown in Table 3 (Example 26), thermal oxidation alone (Example 33) without a preceding acid or base pretreatment step yielded activated carbons with the highest modified contact pH and lowest oxygen concentration, which in turn resulted in the lowest CDN values. [Table 4]

[0083] Changes in contact pH were found to be uncorrelated with the ash level of the activated carbon, as shown in Table 4. Without wishing to be bound by theory, this appears to rule out changes in ash content as a factor in accelerating the destruction of chloramines and peroxides.

[0084] Furthermore, it has been demonstrated that when acid washing and thermal oxidation are performed on coconut carbons such as OLC but without metal species as part of the aqueous additive solution (e.g., containing only a nitrogen source such as urea), the maximum CDN achieved is only 3.3, and peroxide values ​​typically exceed 60 min. Therefore, including metal species in the additive solution is crucial for achieving high performance.

[0085] In Table 5, Examples 35-37 show that when virgin OLC coconut activated carbon is only acid washed, without thermal oxidation, improvements in CDN are realized compared to coconut carbon that was not pretreated at all, as in Example 34. Of the acid pretreatments, sulfuric acid exhibits the highest CDN values ​​without thermal oxidation. Of the three metal-nitrogen species used for loading, the copper-iron-nitrogen species exhibited the highest CDN response when the carbon was simply acid washed. [Table 5]

[0086] Additional testing was conducted to determine the performance of activated carbons formed from coal precursors (sometimes referred to as "coal-based" activated carbons) that were contacted with copper, iron, and nitrogen impregnants to improve chloramine destruction performance. Nitrogen impregnants include, for example, urea. Additional testing also compared activated carbons formed from coconut precursors (sometimes referred to as "coconut-based" activated carbons) with activated carbons formed from coal precursors.

[0087] Further testing was conducted to determine whether impregnating coal-based or coconut-based activated carbon with zinc-iron-nitrogen chemistry would be beneficial.

[0088] Thus, Table 6 lists the CDN performance of Filtrasorb® 400 (also known in the industry as F400), a coal-based activated carbon available from Calgon Carbon Corporation, Moon Township, Pennsylvania, USA. F400 is produced from bituminous coal, which is crushed and reagglomerated during the manufacturing process. F400 has a minimum iodine number of 1000 mg / g and typically has an apparent density of about 0.54 g / cm. 3 is.

[0089] Another purpose of Table 6 is to demonstrate the difference in performance of coal-based activated carbons depending on the treatment prior to decarbonation. As shown in Table 6, Comparative Example 38 shows the baseline performance of F400 without any treatment. Comparative Example 39 shows that thermal oxidation of F400, but no other treatment, nearly doubles the CDN performance. Examples 40-44 demonstrate that acid washing, thermal oxidation, and the addition of a 50:50 copper:iron solution and urea significantly increases measured CDN, in particular. It should be noted that Comparative Examples 38 and 39 were prepared and measured according to columns 11-12 and Table 1 of U.S. Pat. No. 10,702,853, which are incorporated herein by reference in their entirety. [Table 6]

[0090] Among the examples listed in Table 6, Example 43 exhibited the highest CDN, at 46.4. Similar to the coconut activated carbon example listed in Table 1, the best chloramine performance (i.e., the highest CDN) resulted from a process methodology that treated the F400 activated carbon feedstock as follows: first, acid-washed the F400; second, thermally oxidized the F400; third, doped the F400 by contacting it with a metal-nitrogen mixture; and first subjected the F400 to the acid-wash and thermal-oxidation steps prior to the metal-nitrogen doping and final calcination steps. Furthermore, this data demonstrates that superior CDN performance can be achieved using coal-based activated carbon when employing copper-iron-nitrogen chemistry. Comparing Example 43 and Example 44 also highlights the importance of contacting the metal dopant on the surface of the activated carbon when combined with the acid-wash and thermal-oxidation pretreatment steps to achieve the highest CDN values. As shown in Example 44, even when only urea was contacted with the surface of activated carbon to add activated carbon and acid washing and thermal oxidation pretreatment were employed, only a slight improvement in CDN performance was achieved. Again, as shown in Table 6, the manufacturing process of Example 44, in which only urea was contacted, had a CDN of 19.6, while Example 43, in which copper and iron were added to the urea solution, had a CDN of 46.4.

[0091] The above examples describe treating coconut or coal-based activated carbon with various precursors, including copper, iron, and nitrogen (e.g., urea) precursors, to improve the activated carbon's ability to remove chloramines from fluid streams. The activated carbon was further tested to determine the potential benefits of dopant chemistries including zinc, iron, and urea, as follows. In Examples 45-50, the activated carbon feedstock was impregnated with zinc and iron to achieve a total metal loading of approximately 0.50 wt.% based on dry carbon before calcination. Of this metal loading, approximately 50 wt.% was zinc and approximately 50 wt.% was iron. Urea was added to the carbon to achieve a loading of approximately 17 wt.% based on dry carbon before calcination. All examples were calcined at 950°C for greater than 60 minutes in a nitrogen atmosphere. In Table 7, Examples 48 and 50 again demonstrate that acid washing and thermal oxidation pretreatment of the activated carbon feedstock prior to water impregnation and calcination results in very high CDN values ​​of 34.6 for the coal-based F400 product and 71.2 for the coconut-based OLC-AW product.

[0092] Examples 49 and 50 were also tested for "Peroxide Destruction Number." The "Peroxide Destruction Number," also known as the "Peroxide Number," is measured. The Peroxide Number is a volumetric test, meaning that performance is measured and normalized for a specified volume of adsorbent material. Peroxide number testing is well known in the art and is described by U.S. Pat. No. 5,470,748, which is incorporated herein by reference in its entirety.

[0093] During peroxide value testing, the adsorbent material is first ground to a fine mesh size fraction where at least 90 wt%, and in certain tests at least 95 wt%, of the adsorbent material passes through a 325-mesh U.S. Standard Series sieve (44 μm opening). A predetermined amount of ground adsorbent material is placed in a vacuum flask (Dewar), and 100 mL of deionized water is added to the vacuum flask. The deionized water is added so that any ground adsorbent material adhering to the sides of the vacuum flask is carried into the body of water at the bottom of the vacuum flask. Next, 50 mL of an aqueous buffer solution is added to the vacuum flask. The aqueous buffer solution is 0.5 molar KHPO4 and 0.5 molar KHPO4. After the aqueous buffer solution is added, a magnetic stir bar is added to the vacuum flask and energized to begin stirring. The stirring speed is increased until a vortex greater than approximately 0.5 inches (1.27 cm) deep is formed in the mixture and the optimum stir bar speed is reached. The optimum stir bar speed is selected such that further increases in the stir bar speed do not significantly affect the decomposition time of the peroxide.

[0094] As mentioned in the previous paragraph, during the Peroxide Number test, a predetermined amount of sorbent material is added to a buffered hydrogen peroxide solution. Because this test is a volumetric test, the specified amount of sorbent added to the buffered hydrogen peroxide solution is based on one-half the apparent density of the sorbent material. Specifically, the mass of sorbent material in grams added to the solution is calculated based on the apparent density of the sorbent in g / cm. 3 When reported as a function of mass percent, it is equal to one-half the measured apparent density of the adsorbent. In buffer solutions, the catalytic properties of the adsorbent material catalyze and thereby destroy the peroxides (i.e., hydrogen peroxide decomposes into water and oxygen gas).

[0095] The catalytic action of hydrogen peroxide is exothermic. Therefore, assessment of decomposition by the sorbent material can be estimated over time by measuring the temperature of the buffer solution. As used herein, "peroxide number" is the length of time (in minutes) required for a buffer solution containing a sample of the sorbent material to reach 75% of the maximum recorded temperature. A faster time, and therefore a lower peroxide number, indicates more catalytic activity and therefore a higher-performing sorbent material. In some embodiments, the peroxide destruction number, measured in minutes, is about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, about 5.0, about 5.5, about 6.0, about 6.5, about 7.0, or any range formed by two or more of the above values ​​as the endpoints of the range. In some embodiments, the peroxide destruction number, measured in minutes, is about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, or any range formed from two or more of the above values ​​as the endpoints of the range.

[0096] Peroxide values ​​are related to and correlate to some extent with CDN in that each is a measure of the catalytic activity of the adsorbent material. However, the correlation is not necessarily exact, as each represents a different aspect of the adsorbent's catalytic activity. Furthermore, catalytic activity is only useful for the compounds being catalyzed; other compounds must be adsorbed to be effectively removed from the fluid stream. Therefore, a good adsorbent material will have a low peroxide value (measured in minutes) in addition to a high CDN, and ideally, will be tested for adsorption to ensure it can effectively remove a wide range of compounds from the fluid stream.

[0097] Returning to the data in Table 7, Example 50 also demonstrates that a very low peroxide value of approximately 2.3 minutes is possible. This data suggests that the addition of zinc-iron-nitrogen to activated carbon can result in an activated carbon product with excellent chloramine performance, equal to or better than similarly impregnated copper-iron-nitrogen activated carbon. [Table 7]

[0098] Particularly advantageous embodiments of the present disclosure are as follows: Clause 1. The adsorbent material of clause 1, wherein the carbonaceous material is activated to form a precursor activated carbon, wherein the precursor activated carbon is subjected to an acid or base pretreatment and then optionally thermally oxidized, and wherein the precursor activated carbon is contacted with a nitrogen source and a metal source, wherein the precursor activated carbon comprises from about 5% to about 12% nitrogen, measured on a dry precursor activated carbon basis, and from about 0.1% to about 1.0% metal by weight, measured on a dry precursor activated carbon basis. Clause 2. The adsorbent material of clause 1, wherein the adsorbent material has a modified contact pH of from about 3 to about 11. Clause 3. The adsorbent material of clause 1, wherein the pretreatment is with an acid. Clause 4. The sorbent material of clause 3, wherein the acid is any of nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, acetic acid, citric acid, ascorbic acid, or a combination thereof. Clause 5. The adsorbent material of clause 3, wherein the adsorbent material has a modified contact pH of from about 5 to about 8. Clause 6. The adsorbent material of clause 1, wherein the pretreatment is with a base. Clause 7. The sorbent material of clause 6, wherein the base is sodium hydroxide, ammonium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, or a combination thereof. Clause 8. The adsorbent material of clause 6, wherein the adsorbent material has a modified contact pH of from about 7 to about 11. Clause 9. The sorbent material of clause 1, wherein the metal is selected from iron, copper, zinc, or combinations thereof. Clause 10. The sorbent material of clause 1, wherein the carbonaceous material is formed from one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, pits, coconut shells, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitch, bagasse, rice husks, corn husks, wheat husks and rice husks, graphene, carbon nanotubes, or polymer fibers. Clause 11. The adsorbent material of clause 1, wherein the carbonaceous material is formed from coconut shells. Clause 12. The sorbent material of clause 1, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 10 to about 75. Clause 13. The sorbent material of clause 1, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 37 to about 72. Clause 14. The adsorbent material of clause 1, wherein the adsorbent material has a peroxide value of from about 2 minutes to about 40 minutes. Clause 15. The adsorbent material of clause 1, wherein the adsorbent material has a peroxide value of from about 2.6 minutes to about 3.7 minutes. Clause 16. The adsorbent material of clause 1, wherein the adsorbent material has an oxygen content of about 3% to about 9%. Clause 17. A method of producing an adsorbent material, the method comprising the steps of providing a carbonaceous material; activating the carbonaceous material to form a precursor activated carbon; pretreating the precursor activated carbon with an acid or a base; optionally thermally oxidizing the precursor activated carbon at a temperature of about 450°C; contacting the precursor activated carbon with a metal source and a nitrogen source to form a loaded precursor activated carbon; and calcining the loaded precursor activated carbon at a temperature of about 950°C. Clause 18. The adsorbent material of clause 17, wherein the carbonaceous material is formed from one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, wood, wood chips, sawdust, peat, nut shells, pits, coconut shells, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, lignin, polymers, nitrogen-containing polymers, resins, petroleum pitch, bagasse, rice husks, corn husks, wheat husks and rice husks, graphene, carbon nanotubes, or polymer fibers. Clause 19. The method of claim 17, wherein the carbonaceous material is formed from coconut shells. Clause 20. The method of claim 17, wherein the acid is any of nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, acetic acid, citric acid, ascorbic acid, or a combination thereof. Clause 21. The method of claim 17, wherein the base is ammonium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, or a combination thereof. Clause 22. The method of claim 17, wherein the metal source is any of copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) hydroxide carbonate, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof. Clause 23. The method of claim 17, wherein the nitrogen source has an oxidation state of -3. Clause 24. The method of claim 17, wherein the nitrogen source comprises urea, dicyandiamide, melamine, or a combination thereof. Clause 25. The method of claim 17, wherein the adsorbent material has a modified contact pH of from about 5 to about 11. Clause 26. The method of claim 17, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 10 to about 75. Clause 27. The method of claim 17, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 37 to about 72. Clause 28. The method of claim 17, wherein the adsorbent material has a peroxide value of from about 2 minutes to about 40 minutes. Clause 29. The method of claim 17, wherein the adsorbent material has a peroxide value of about 2.6 minutes to about 3.7 minutes. Clause 30. The method of claim 17, wherein the adsorbent material has about 3% to about 9% oxygen. Clause 31. A method for treating water potentially containing chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, volatile organic compounds, or combinations thereof, comprising the steps of contacting the water with a sorbent material comprising activated carbon formed from a carbonaceous material, the activated carbon being pretreated with an acid or a base, then thermally oxidized, and then doped with a metal source and a nitrogen source; and contacting the water with the sorbent material removes one or more of the chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, and volatile organic compounds. Clause 32. The method of claim 29, wherein the carbonaceous material is one or more of coconut shells. Clause 33. The method of claim 31, wherein the metal source is any of copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) hydroxide carbonate, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof. Clause 34. The method of claim 31, wherein the nitrogen source has an oxidation state of -3. Clause 35. The method of claim 31, wherein the nitrogen source comprises urea, dicyandiamide, melamine, or a combination thereof. Clause 36. The method of claim 31, wherein the adsorbent material has a modified contact pH of from about 3 to about 11. Clause 37. The method of claim 31, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 10 to about 75. Clause 38. The method of claim 31, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 37 to about 72. Clause 39. The method of claim 31, wherein the adsorbent material has a peroxide value of from about 2 minutes to about 40 minutes. Clause 40. The method of claim 31, wherein the adsorbent material has a peroxide value of from about 2.6 minutes to about 3.7 minutes. Clause 41. The method of claim 31, wherein the adsorbent material has an oxygen content of about 3% to about 9%.

[0099] In the above detailed description, reference is made to the accompanying drawings, which form a part of this specification. In the drawings, like numerals generally identify like elements unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that aspects of the present disclosure, as generally described herein and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are expressly contemplated herein.

[0100] The present disclosure is not limited in terms of the specific embodiments described in this application, which are intended as illustrative of various aspects. It will be apparent to those skilled in the art that many modifications and variations can be made without departing from the spirit and scope of the present disclosure. Functionally equivalent methods and apparatuses within the scope of the present disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to be included within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that the present disclosure is not limited to particular methods, reagents, compounds, compositions, or biological systems. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0101] With respect to the use of virtually any plural and / or singular term herein, those of skill in the art can translate from plural to singular and / or from singular to plural as appropriate to the context and / or application. Various singular / plural permutations may be expressly provided herein for clarity.

[0102] In general, those skilled in the art will understand that the terms used in this specification, and particularly in the appended claims (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "comprise" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "comprising" should be interpreted as "including, but not limited to," etc.). Although various compositions, methods, and devices are described in terms "consisting of" various components or steps (interpreted to mean "including, but not limited to"), compositions, methods, and devices can also "consist essentially of" or "consist of" various components and steps, and such terms should be interpreted to define essentially closed member groups. Those skilled in the art will further understand that if a specific number of recitations of the introduced claims are intended, such intention will be explicitly recited in the claims; in the absence of such recitation, no such intention exists.

[0103] For example, as an aid to understanding, the following appended claims may use the introductory phrases "at least one" and "one or more" to introduce claim recitation. However, the use of such phrases should not be construed to mean that introducing a claim recitation with the indefinite article "a" or "an" limits a particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even if the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"); nor should the use of definite articles used to introduce claim recitations be construed as meaning "at least one" or "one or more").

[0104] Additionally, even when a specific number of introduced claims is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number of times (e.g., the bare recitation of "two iterations" without other modifiers means at least two iterations, or more than two iterations). Furthermore, when idiomatic phrases similar to "at least one of A, B, and C, etc." are used, such syntax is generally intended in the sense that one skilled in the art would understand the idiomatic phrase (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, A alone, B alone, C alone, a system having A and B together, a system having A and C together, a system having B and C together, and / or a system having A, B, and C together, etc.). When phrases similar to "at least one of A, B, or C, etc." are used, generally, such configuration is intended in the sense that one of ordinary skill in the art would understand the phrase (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, a system having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Those of ordinary skill in the art will further understand that virtually any conjunction word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" is understood to include the possibilities of "A" or "B," or "A and B."

[0105] Additionally, when features or aspects of the disclosure are described in terms of a Markush group, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0106] Those skilled in the art will understand that, for all purposes, including in terms of providing a written description, all ranges disclosed herein encompass all possible subranges and combinations of subranges. Any recited range can be readily recognized as fully descriptive and permitting the same range to be broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third, upper third, etc. Those skilled in the art will also understand that all terms such as "up to," "at least," etc., are inclusive of the recited number and refer to ranges that can then be broken down into subranges as described above. Finally, those skilled in the art will understand that ranges include individual members. Thus, for example, a group having 1 to 3 compounds refers to groups having 1, 2, or 3 compounds. Similarly, a group having 1 to 5 compounds refers to groups having 1, 2, 3, 4, or 5 compounds, etc.

[0107] Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unforeseen alternatives, modifications, variations, or improvements may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.

Claims

1. 10. The adsorbent material of claim 1, a carbonaceous material that has been activated to form a precursor activated carbon; The precursor activated carbon is subjected to an acid or base pretreatment and then optionally thermally oxidized; and The precursor activated carbon is contacted with a nitrogen source and a metal source, and the adsorbent material comprises from about 5% to about 12% nitrogen, measured on a dry precursor activated carbon basis, and from about 0.1% to about 1.0% metal by weight, measured on a dry precursor activated carbon basis.

2. The adsorbent material of claim 1, wherein the adsorbent material has a modified contact pH of from about 3 to about 11.

3. 10. The adsorbent material of claim 1, wherein the pretreatment is with an acid.

4. 4. The sorbent material of claim 3, wherein the acid is any of nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, acetic acid, citric acid, ascorbic acid, or a combination thereof.

5. The adsorbent material of claim 3, wherein the adsorbent material has a modified contact pH of from about 5 to about 8.

6. 10. The adsorbent material of claim 1, wherein the pretreatment is with a base.

7. 7. The sorbent material of claim 6, wherein the base is any of sodium hydroxide, ammonium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, or a combination thereof.

8. The adsorbent material of claim 6, wherein the adsorbent material has a modified contact pH of from about 7 to about 11.

9. 10. The sorbent material of claim 1, wherein the metal is selected from iron, copper, zinc, or combinations thereof.

10. The sorbent material of claim 1 , wherein the carbonaceous material is formed from one or more of coconut shell, bituminous coal, sub-bituminous coal, lignite, or anthracite.

11. The sorbent material of claim 1, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 10 to about 75.

12. The sorbent material of claim 1, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 37 to about 72.

13. The sorbent material of claim 1, wherein the sorbent material has a peroxide value of from about 1.5 minutes to about 40 minutes.

14. The sorbent material of claim 1, wherein the sorbent material has a peroxide value of from about 2.6 minutes to about 3.7 minutes.

15. The sorbent material of claim 1, wherein the sorbent material has an oxygen content of about 3% to about 9%.

16. 1. A method of making an adsorbent material, said method comprising: providing a carbonaceous material; activating the carbonaceous material to form a precursor activated carbon; pretreating the precursor activated carbon with an acid or a base; Optionally, thermally oxidizing the precursor activated carbon at a temperature of about 450°C; contacting the precursor activated carbon with a metal source and a nitrogen source to form a loaded precursor activated carbon; calcining the added precursor activated carbon at a temperature of about 950°C; A method comprising:

17. 17. The method of claim 16, wherein the carbonaceous material is formed from one or more of coconut shells, bituminous coal, sub-bituminous coal, lignite, or anthracite.

18. 17. The method of claim 16, wherein the acid is any of nitric acid, sulfuric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, acetic acid, citric acid, ascorbic acid, or a combination thereof.

19. 17. The method of claim 16, wherein the base is ammonium hydroxide, sodium hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, or a combination thereof.

20. 17. The method of claim 16, wherein the metal source is any of copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) hydroxide carbonate, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof.

21. 17. The method of claim 16, wherein the nitrogen source has an oxidation state of -3.

22. 17. The method of claim 16, wherein the nitrogen source comprises urea, dicyandiamide, melamine, or a combination thereof.

23. 17. The method of claim 16, wherein the adsorbent material has a modified contact pH of from about 5 to about 11.

24. 17. The method of claim 16, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 10 to about 75.

25. 17. The method of claim 16, wherein the sorbent material has a Chloramine Destruction Number (CDN) of about 37 to about 72.

26. 17. The method of claim 16, wherein the adsorbent material has a peroxide value of from about 1.5 minutes to about 40 minutes.

27. 17. The method of claim 16, wherein the adsorbent material has a peroxide value of from about 2.6 minutes to about 3.7 minutes.

28. 17. The method of claim 16, wherein the adsorbent material has about 3% to about 9% oxygen.

29. 1. A method for treating water potentially containing chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, volatile organic compounds, or combinations thereof, comprising: contacting water with an adsorbent material comprising activated carbon formed from a carbonaceous material, the activated carbon being pretreated with an acid or a base, then thermally oxidized, and then charged with a metal source and a nitrogen source; and contacting the water with a sorbent material to remove one or more of chlorine, chloramines, chloroform, trihalomethanes, haloacetic acids, peroxides, and volatile organic compounds.

30. 30. The method of claim 29, wherein the carbonaceous material is one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, or coconut shell.

31. 30. The method of claim 29, wherein the metal source is any of copper(II) sulfate pentahydrate, copper(II) chloride, copper(II) nitrate, copper(II) acetate, copper(II) hydroxide carbonate, copper(II) formate, copper(II) formate tetrahydrate, iron(II) chloride, iron(III) chloride, zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, hydrates thereof, or combinations thereof.

32. 30. The method of claim 29, wherein the nitrogen source has an oxidation state of -3.

33. 30. The method of claim 29, wherein the nitrogen source comprises urea, dicyandiamide, melamine, or a combination thereof.

34. 30. The method of claim 29, wherein the adsorbent material has a modified contact pH of from about 3 to about 11.

35. 30. The method of claim 29, wherein the sorbent material has a Chloramine Destruction Number (CDN) of from about 10 to about 75.

36. 30. The method of claim 29, wherein the sorbent material has a Chloramine Destruction Number (CDN) of from about 37 to about 72.

37. 30. The method of claim 29, wherein the adsorbent material has a peroxide value of from about 1.5 minutes to about 40 minutes.

38. 30. The method of claim 29, wherein the adsorbent material has a peroxide value of from about 2.6 minutes to about 3.7 minutes.

39. 30. The method of claim 29, wherein the sorbent material has an oxygen content of about 3% to about 9%.

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