CN1741965A - Water filter material and method for manufacturing water filter - Google Patents

Abstract

A process for producing a water filter material is provided. The process includes the steps of providing a plurality of mesoporous activated carbon particles, and treating said plurality of mesoporous activated carbon particles to produce a plurality of mesoporous activated carbon particles having a bulk oxygen percentage by weight of less than about 2.3%.

Description

Water filter material and method for manufacturing water filter

technical field

The present invention relates to the field of water filter materials and methods of making water filters. More specifically, the present invention relates to the field of water filter manufacturing methods comprising mesoporous activated carbon particles.

Background technique

Water can contain many different types of pollutants including, for example, particulates, harmful chemicals and microbial organisms such as bacteria, parasites, protozoa and viruses. In many cases, these contaminants must be removed before the water can be used. For example, highly pure water is required in many medical applications and in the manufacture of certain electronic components. Another, more general example is that water must be free of any harmful contaminants before it can be potable (ie suitable for drinking). Despite modern methods of water purification, there are still risks for the average person, especially for infants and people with compromised immune systems.

In the United States and other developed countries, municipally treated water typically contains one or more of the following impurities: suspended solids, bacteria, parasites, viruses, organic matter, heavy metals, and chlorine. Sometimes, water treatment system malfunctions and other problems prevent bacteria and viruses from being completely removed from the water. In other countries, exposure to polluted water has had fatal consequences due to increasing population density, dwindling water sources and no water treatment facilities in some areas. Since drinking water sources are commonly adjacent to human and animal waste, microbial contamination is a major health concern. Pollution from microbial growth in the water is estimated to kill about six million people a year, half of them children under the age of five.

In 1987, the U.S. Environmental Protection Agency (EPA) proposed "Guiding Standards and Protocols for Testing Microbial Water Purifiers." The Protocol establishes minimum requirements for the performance of drinking-water treatment systems designed to reduce certain specific pollutants affecting health in public and private water supplies. It is required that the virus removal rate in the water flowing out of the supply water source is 99.99% (or equivalent to 4 log), and the bacterial removal rate is 99.9999% (or equivalent to 6 log) to meet the requirements. According to the EPA protocol, the concentration of virus in the influent water should be 1×10 ⁷ per liter, and the concentration of bacteria in the influent water should be 1×10 ⁸ per liter. Because of the ubiquity of E. coli (bacteria) in water supplies and the risks associated with drinking them, this microorganism was used as the bacterium in most studies. Similarly, MS-2 bacteriophage (or simply MS-2 bacteriophage) is a representative microorganism typically used for virus clearance because of its size and shape (i.e., about 26 nm and icosahedral) comparable to many viral resemblance. Therefore, the ability of the water filter to remove the MS-2 bacteriophage can be used to represent its ability to remove other viruses.

Due to these demands and the general interest in improving the quality of drinking water, there remains a need for a filter material and method of manufacturing a filter capable of removing bacteria and/or viruses from a fluid.

Summary of the invention

The invention provides a manufacturing method of a water filter material. The method includes the steps of providing a plurality of mesoporous activated carbon particles and treating the plurality of mesoporous activated carbon particles to produce a plurality of mesoporous activated carbon particles having a weight percent bulk oxygen of less than about 5%.

Brief description of the drawings

Although the specification concludes by claims which particularly point out and distinctly claim the invention, it is believed that the invention will be better understood from the following description when taken in conjunction with the accompanying drawings, in which:

Figure 1a shows the BET nitrogen adsorption isotherms of mesoporous acidic activated carbon particles CA-10 and mesoporous basic oxygen-reducing activated carbon particles TA4-CA-10;

Figure 1b shows the BET nitrogen adsorption isotherms of mesoporous alkaline activated carbon particles RGC and mesoporous alkaline reduced oxygen activated carbon THe4-RGC;

Figure 2a shows the mesopore volume distribution of the particles in Figure 1a.

Figure 2b shows the mesopore volume distribution of the particles in Figure 1b.

Figure 3a is a diagram of the point of zero charge for the particles in Figure 1a.

Figure 3b is a graph of the point of zero charge for the particles in Figure 1b.

Figure 4 is a cross-sectional side view of an axial flow filter made in accordance with the present invention.

Figure 5a graphically illustrates the E. coli bath concentration of the activated carbon granules in Figure 1a as a function of time.

Figure 5b graphically illustrates the E. coli bath concentration of the activated carbon granules in Figure 1b as a function of time.

Figure 6a graphically illustrates the MS-2 bath concentration of the activated carbon particles in Figure 1a as a function of time.

Figure 6b graphically illustrates the MS-2 bath concentration of the activated carbon particles in Figure Ib as a function of time.

Figure 7a graphically illustrates the flow concentration of E. coli as a function of the cumulative volume of water passed through 2 filters; one filter containing RGC mesoporous alkaline activated carbon and the other containing coconut microporous activated carbon particles.

Figure 7b graphically illustrates the MS-2 flow concentration as a function of the cumulative volume of water passed through 2 filters; one filter containing RGC mesoporous basic activated carbon and the other containing coconut microporous activated carbon particles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

All cited documents are, in relevant part, incorporated herein by reference. The citation of any document is not to be construed as an admission that it is available as prior art to the present invention.

I. Definition

As used herein, the terms "filter" and "filtration" refer to structures or mechanisms associated with the removal of microorganisms (and/or removal of other contaminants) to a lesser extent by primarily adsorption and/or size exclusion, respectively.

As used herein, the phrase "filter material" means an aggregate of filter particles. This aggregate of filter particles forming the filter material may be homogeneous or heterogeneous. The filter particles may be distributed uniformly or non-uniformly (eg layers of different filter particles) within the filter material. The filter particles forming the filter material also need not be of the same shape or size and may be provided in loose or interconnected form. For example, the filter material may comprise mesoporous basic activated carbon particles combined with activated carbon fibers either provided in loose association or formed into a unitary structure by a polymeric binder or otherwise partially or fully bonded.

As used herein, the phrase "filter particle" means an individual member or strip used to form at least part of a filter material. For example, a fiber, a particle, a bead, etc. are considered a filter particle in the present invention. In addition, the filter particles can vary in size from imperceptible filter particles (eg, very fine powders) to palpable filter particles.

The phrase "filter material pore volume" as used herein refers to the total volume of intergranular pores in the filter material having a size greater than 0.1 μm.

As used herein, the phrase "total filter material volume" refers to the sum of the interparticle pore volume and the volume occupied by the filter particles.

As used herein, the terms "microorganism", "microbial organism" and "germ" are used interchangeably. These terms refer to various microorganisms with characteristics of bacteria, viruses, parasites, protozoa and germs.

The "Bacterial Removal Index" (BRI) of a filter particle as used herein is defined as:

BRI=100×[1-Escherichia coli equilibrium state bath concentration/Escherichia coli control concentration)],

Wherein "Escherichia coli equilibrium bath concentration" refers to the concentration of bacteria at equilibrium in a bath containing a large number of filter particles with a total external area of 1400 cm ² and a Sauter mean diameter of less than 55 μm, as described in more detail below. Tests were performed at two time points 2 hours apart, and equilibrium was achieved when the E. coli concentration remained within half an order of magnitude. The phrase "E. coli control concentration" refers to the concentration of E. coli in the control bath, which is equal to about 3.7 x ¹⁰⁹ CFU/L. The Sauter mean diameter refers to the diameter of a particle whose area-to-volume ratio is the same as that of the entire particle distribution. Note that the term "CFU/L" means "colony forming units per liter", which is a typical term used for enumeration of E. coli. The BRI index is measured without the use of chemicals that have a bactericidal effect. A comparable way of expressing the bacteria-removing ability of filter particles is to use the "Bacterial Log Removal Index" (BLRI), which is defined as:

BLRI=-log[1-(BRI/100)]. The BLRI index is in "log" units (where "log" stands for logarithm). For example, when the BRI index of the filter particles is equal to 99.99%, it is equivalent to the BLRI index equal to 4log. The test procedures for the BRI and BLRI indices are given below.

The "Virus Removal Index" (VRI) of a filter particle as used herein is defined as:

VRI=100×[1-(MS-2 phage equilibrium state bath concentration/MS-2 phage control concentration)], wherein "MS-2 phage equilibrium state bath concentration" refers to the concentration of phage in the equilibrium state in the bath, the bath contains a large number of filter particles with a total external area of 1400 cm ² and a Sauter mean diameter of less than 55 μm, as described in more detail below. Tests were performed at two time points 2 hours apart, and equilibrium was achieved when the MS-2 concentration remained constant within half an order of magnitude. The phrase "MS-2 phage control concentration" refers to the concentration of MS-2 phage in the control bath, which is equal to about 6.7 x 10 ⁷ PFU/L. Note that the term "PFU/L" means "phage forming units per liter", which is a typical term used for MS-2 enumeration. The VRI index is measured without the use of chemical agents with bactericidal effect. A comparable way of expressing the germ-killing ability of filter particles is to use the "Virus Log Removal Index" (VLRI), which is defined as:

VLRI=-log[1-(VRI/100)]. The VLRI index is in "log" units (where "log" stands for logarithm). For example, the VRI of filter particles is equal to 99.9%, then its VLRI is equal to 3log. The test procedure for VRI and VLRI values is given below.

As used herein, the phrase "filter bacterial log removal (F-BLR)" refers to the bacterial removal capacity of a filter after flow through the first 2,000 filter material pore volumes. F-BLR is defined and calculated as follows:

F-BLR=-log[(outflow concentration of E. coli)/(inflow concentration of E. coli)], wherein the "inflow concentration of E. coli" is continuously set at about 1×10 ⁸ CFU/L throughout the test, And the "effluent concentration of E. coli" was measured after about 2,000 filter material pore volumes had flowed through the filter. The F-BLR is in "log" units (where "log" stands for logarithm). Note that if the effluent concentration is below the detection limit of the assay technique, it is considered to be the detection limit for the calculation of F-BLR. Also, note that F-BLR was measured without the use of bactericidal chemicals.

As used herein, the phrase "filter virus log removal (F-VLR)" refers to the virus removal capacity of a filter after flow through the first 2,000 pore volumes of the filter material.

F-VLR is defined and calculated as follows:

F-VLR=-log[(outflow concentration of MS-2)/(inflow concentration of MS-2)],

In which the "inflow concentration of MS-2" was continuously set at about 1×10 ⁷ PFU/L throughout the test, and the "outflow concentration of MS-2" was measured after about 2,000 filter material pore volumes had flowed through the filter . The F-VLR is in "log" units (where "log" stands for logarithm). Note that if the effluent concentration is below the detection limit of the assay technique, it is considered to be the detection limit for the calculation of F-VLR. Also, note that F-VLR was measured in the absence of bactericidal chemicals.

As used herein, the phrase "total external area" means the total geometric external area of one or more filter particles, as described in more detail below.

As used herein, the phrase "specific external surface area" means the total external surface area per unit mass of filter particles, as described in more detail below.

As used herein, the term "micropore" means pores within a particle having a width or diameter of less than 2 nm (or equivalently 20 Å).

The term "mesopore" as used herein means pores within a particle having a width or diameter between 2 nm and 50 nm (or equivalently between 20 Å and 500 Å).

As used herein, the term "macropore" means pores within a particle having a width or diameter greater than 50 nm (or equivalently 500 Å).

As used herein the phrase "total pore volume" and its derivatives mean the volume of all pores within the particle, ie micropores, mesopores and macropores. The total pore volume was calculated as the nitrogen adsorption volume measured by the BET method (ASTM D 4820-99 standard) well known in the art at a relative pressure of 0.9814.

As used herein, the phrase "pore volume" and its derivatives mean the volume of all pores. The micropore volume is calculated as the nitrogen adsorption volume measured by the BET method (ASTM D 4820-99 standard) well known in the art at a relative pressure of 0.15.

The phrase "sum of mesopore and macropore volume" and its derivatives as used herein means the volume of all mesopores and macropores. The sum of the mesopore and macropore volumes is equal to the difference between the total pore volume and the micropore volume, or equivalently, calculated at relative pressures of 0.9814 and 0.15, respectively, by the BET method well known in the art (ASTM D 4820-99 standard ) The difference between the nitrogen adsorption volumes measured.

As used herein, the phrase "pore size distribution in the mesopore range" means the pore size distribution calculated by the Barrett, Joyner and Halenda (BJH) method well known in the art.

As used herein, the term "carbonization" and its derivatives mean the process of reducing non-carbon atoms in a carbonaceous material.

As used herein, the term "activation" and its derivatives mean a method of making a carbonized material more porous.

As used herein, the term "activated carbon particles" or "activated carbon filter particles" and their derivatives means carbonized particles that have undergone an activation process.

As used herein, the phrase "point of zero charge" means the critical pH value above which the total surface charge of the carbonized particles becomes negatively charged. Well-known test procedures for determining the point of zero charge are set forth below.

The term "basic" as used herein means that the filter particles have a point of zero charge greater than 7.

The term "acidic" as used herein means that the filter particles have a point of zero charge of less than 7.

As used herein, the phrase "mesoporous activated carbon filter particle" means an activated carbon filter particle in which the sum of the mesopore and macropore volumes is greater than 0.12 mL/g.

As used herein, the phrase "microporous activated carbon filter particle" means an activated carbon filter particle in which the sum of the mesopore and macropore volumes is less than 0.12 mL/g.

As used herein, the phrase "medium pore basic activated carbon filter particle" means an activated carbon filter particle in which the sum of the mesopore and macropore volumes is greater than 0.12 mL/g and the point of zero charge is greater than 7.

As used herein, the phrase "mesoporous basic oxygen-reducing activated carbon filter particle" means an activated carbon filter particle in which the sum of the mesopore and macropore volumes is greater than 0.12 mL/g, the point of zero charge is greater than 7, and the weight percent bulk oxygen is 1.5 % or less.

As used herein, the phrase "mesoporous acidic activated carbon filter particle" means an activated carbon filter particle in which the sum of the mesopore and macropore volumes is greater than 0.12 mL/g and the point of zero charge is less than 7.

As used herein, the phrase "feedstock" refers to any precursor comprising mesopores and macropores or capable of producing mesopores and macropores during carbonization and/or activation.

As used herein, the phrase "axial flow" means flow across a planar surface and perpendicular to the surface.

As used herein, the phrase "runoff" typically refers to flow across substantially cylindrical or substantially conical surfaces, and perpendicular to those surfaces.

As used herein, the phrase "frontal area" refers to the area of the filter material that is initially exposed to influent water. For example, in an axial flow filter, the frontal area is the cross-sectional area of the filter material at the fluid inlet, while in a radial flow filter, the frontal area is the outer area of the filter material.

The phrase "filtration depth" as used herein refers to the linear distance of influent water from the inlet to the outlet of the filter material. For example, in an axial flow filter, the depth of filtration is the thickness of the filter material, while in a radial flow filter, the depth of filtration is half the difference between the outer and inner diameters of the filter material.

The phrases "average fluid residence time" and/or "average fluid contact time" as used herein refer to the average time that a fluid is in contact with the filter particles in the filter as it flows through the filter material, and is calculated as the ratio of the pore volume of the filter material to the Ratio of fluid flow rates.

As used herein, the phrase "filter porosity" and/or "filter bed porosity" refers to the ratio of the pore volume of the filter material to the total volume of the filter material.

The phrase "inlet" as used herein refers to the part through which fluid can enter the filter or filter material. For example, the inlet can be part of the structure of the filter, or be a frontal area of the filter material.

As used herein, "outlet" refers to a component through which fluid can flow out of a filter or filter material. For example, the outlet may be part of the filter structure, or be the cross-sectional area of the filter material at which the fluid exits.

II. Mesoporous activated carbon filter particles

It was unexpectedly found that mesoporous activated carbon filter particles adsorbed a higher amount of microorganisms than microporous activated carbon filter particles. It was also unexpectedly found that mesoporous basic activated carbon filter particles adsorbed a greater number of microorganisms than mesoporous acidic activated carbon filter particles. In addition, it was unexpectedly found that the mesoporous alkaline reduced oxygen activated carbon filter particles adsorbed a greater amount of microorganisms than the mesoporous basic activated carbon filter particles without reducing the weight percent of bulk oxygen adsorbed.

While not wishing to be bound by any theory, with regard to porosity, applicants postulate that the large number of mesopores and/or macropores is responsible for the pathogens, their pili and surface polymers (e.g., proteins) that make up the pathogen outer membrane, capsid and envelope , lipopolysaccharides, oligosaccharides, and polysaccharides) provide more convenient adsorption sites (openings or entrances of meso/macropores), since the typical size of such substances is similar to the entrance size of mesopores and macropores. In addition, mesoporosity and macroporosity may be related to one or more surface properties of carbon such as surface roughness.

Furthermore, without being bound by theory, applicants hypothesize that the surface of the basic activated carbon contains the type of functionality necessary to attract a greater amount of microorganisms relative to the surface of the acidic activated carbon. The enhanced ability to adsorb to the surface of basic activated carbon may be attributed to the fact that the surface of basic activated carbon attracts typically negatively charged microorganisms and their functional groups on the surface. Applicants further hypothesize that when placed in water, alkaline activated carbon is capable of producing a disinfectant by reducing molecular oxygen. Although the final product of the reduction is hydroxide, applicants believe that reactive oxygen intermediates such as peroxides, hydrogen peroxides and/or hydroxyl groups are formed and are sufficiently long-lived to diffuse from the carbon into the bulk solution.

In addition, applicants believe that as the weight percent bulk oxygen decreases, the carbon becomes more basic. Low bulk oxygen weight percent can lead to improved bacteria/virus adsorption due to: (1) less carboxylic acid and thus less negative surface to repel bacteria/viruses; and (2) less hydrated surface allowing Water is more easily displaced by bacteria/viruses as they try to adsorb to the surface (ie, less energy is lost when bacteria/viruses displace other species already occupying surface sites). The latter reason (i.e., less hydrated surface) is also consistent with the idea that the ideal surface (discussed below) should be slightly hydrophobic (in other words, the ideal surface should have enough oxygen substitution on the edge carbon atoms to to make it wet, but not to displace so much that it becomes too hydrophilic).

Filter particles can be made in a variety of shapes and sizes. For example, filter particles can be manufactured in simple shapes such as powders, granules, fibers and beads. Filter particles can be made into spherical, polyhedral, cylindrical, and other symmetrical, asymmetrical, and irregular shapes. Furthermore, filter particles can also be formed in composite forms, such as nets, curtains, grids, nonwoven materials, woven materials, and bonded blocks, which may or may not be formed from the simple forms described above.

The filter particles can vary in shape and size, and the filter particles used in any single filter need not be uniform in size. In fact, it is also advisable that the filter particles in a single filter have different sizes. Typically, the size of the filter particles is between about 0.1 μm and about 10 mm, preferably between about 0.2 μm and about 5 mm, more preferably between about 0.4 μm and about 1 mm, most preferably between about 1 μm and about Between 500μm. For spherical and cylindrical particles (such as fibers, beads, etc.), the above dimensions refer to the diameter of the filter particle. For filter particles of substantially different shapes, the above dimensions refer to their largest dimension (eg length, width or height).

The filter particles may be the product of any precursor comprising mesopores and macropores or capable of producing mesopores and macropores during carbonization and/or activation. For example, and without limitation, the filter particles may be wood-based activated carbon particles, coal-based activated carbon particles, peat-based activated carbon particles, bitumen-based activated carbon particles, tar-based activated carbon particles, soy-based activated carbon particles, other lignocellulosic-based activated carbon particles, and their mixture.

Activated carbon can behave as acidic, neutral or basic. Acidity is associated with oxygen-containing functions or functional groups such as, but not limited to, phenols, carboxyls, lactones, hydroquinones, anhydrides, and ketones. Basicity has so far been associated with functionalities such as pyrones, benzopyrans, ethers, carbonyls, and basal plane π electrons. The acidity or basicity of activated carbon particles is determined by the "point of zero charge" method (Newcombe, G. et al., Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 78, pp. 65-71 (1993)), incorporated here This article is for reference only. This technique is further described in Section VI hereafter. The filter particles of the present invention may have a point of zero charge between 1 and 14, preferably greater than about 4, preferably greater than about 6, preferably greater than about 7, preferably greater than about 8, more preferably greater than about 9, most preferably between about Between 9 and about 12.

The point of zero charge of activated carbon is inversely related to the weight percent of bulk oxygen. The filter particles of the present invention may have a weight percent bulk oxygen of less than about 5%, preferably less than about 2.5%, preferably less than about 2.3%, preferably less than about 2%, more preferably less than about 1.2%, most preferably less than about 1%, and and/or greater than about 0.1%, preferably greater than about 0.2%, more preferably greater than about 0.25%, most preferably greater than about 0.3%. The point of zero charge of activated carbon particles is also related to the oxidation-reduction potential (ORP) of the water comprising the particles, since the point of zero charge is a measure of the carbon's ability to reduce oxygen (at least for basic carbons). The filter particles of the present invention may have an oxidation-reduction potential (ORP) of less than about 570 mV, preferably less than about 465 mV, preferably less than about 400 mV, preferably less than about 360 mV, preferably less than about 325 mV, most preferably between about 290 mV and about 175 mV.

The electrical resistance of activated carbon filter particles or filter materials is one of their important properties, since electrical resistance relates to their ability to form filter blocks. For example, a filter block can be formed using a resistive heating method, in which the filter material is heated by applying an electric current to its 2 ends. The electrical resistance of the filter material will control its ability to heat up in a short period of time. The resistance was measured by forming a filter block using the conditions mentioned in Examples 3 and 4 above, and the resistance between the two faces was measured by bringing the two faces of the filter block into contact with the two electrodes of the voltmeter. Exemplary resistances for the filters in Examples 3 and 4 are about 350Ω and about 40Ω, respectively. Also, the resistances of filters made with CARBOCHEM CA-10 in the above-mentioned Example 1 and TA4-CA10 in the above-mentioned Example 2 were about 1.3 MΩ and about 100 Ω, respectively.

Filter particles can be obtained by processing the raw material as described below. The processing conditions may include atmospheric composition, pressure, temperature and/or time. The atmosphere of the present invention may be a reducing atmosphere or an inert atmosphere. Heating the filter particles in the presence of a reducing atmosphere, steam or an inert atmosphere can result in a filter material with reduced surface oxygen functionality. Examples of suitable reducing atmospheres may include hydrogen, nitrogen, dissociated ammonia, carbon monoxide, and/or mixtures thereof. Examples of suitable inert atmospheres may include argon, helium, and/or mixtures thereof.

When the activated carbon particles do not contain any noble metal catalysts (such as platinum, gold, palladium), the treatment temperature can be between about 600°C and about 1,200°C, preferably between about 700°C and about 1,100°C, more preferably between about 800°C °C and about 1,050 °C, most preferably between about 900 °C and about 1,000 °C. If the activated carbon particles contain a noble metal catalyst, the treatment temperature may be between about 100°C and about 800°C, preferably between about 200°C and about 700°C, more preferably between about 300°C and about 600°C, most preferably between Between about 350°C and about 550°C.

The treatment time may be between about 2 minutes and about 10 hours, preferably between about 5 minutes and about 8 hours, more preferably between about 10 minutes and about 7 hours, most preferably between about 20 minutes and about 6 hours between. The gas flow rate may be between about 0.25 standard L/hg (i.e., standard liters per gram of carbon per hour; 0.009 standard ^ft3 /hg) and about 60 standard L/hg (2.1 standard ^ft3 /hg), preferably between about 0.5 Between standard L/hg (0.018 standard ^ft3 /hg) and about 30 standard L/hg (1.06 standard ^ft3 /hg), more preferably between about 1.0 standard L/hg (0.035 standard ^ft3 /hg) and about 20 standard Between L/hg (0.7 gauge ft ³ /hg), most preferably between about 5 gauge L/hg (0.18 gauge ft ³ /hg) and about 10 gauge L/hg (0.35 gauge ft ³ /hg). The pressure can be maintained greater than, equal to or less than atmospheric pressure during processing. It should be recognized that other methods of making mesoporous basic reduced oxygen activated carbon filter materials can also be used.

Also, depending on the raw material used, such treatment of the raw material as described above may be repeated several times in order to obtain a filter material.

Starting materials are commercially available or prepared by methods well known in the art, for example Jagtoyen, M. and F. Carbon, Derbyshire, Vol. 36 (Nos. 7-8), pp. 1085-1097 (1998), Evans et al. Carbon, Vol. 37, pp. 269-274 (1999), and Ryoo et al., J. Phys. Chem B, Vol. 103 (No. 37), pp. 7743-7746 (1999), The contents of which are incorporated herein by reference. Typical chemicals used for activation/carbonization include phosphoric acid, zinc chloride, ammonium phosphate, etc., which can be used in conjunction with the methods described in the two just cited journals.

Brunauer, Emmett and Teller (BET) specific surface area and Barrett, Joyner and Halenda (BJH) pore size distribution can be used to characterize the pore structure of particles. Preferably, the BET specific surface area of the filter particles is between about 500 m ² /g and about 3,000 m ² /g, preferably between about 600 m ² /g and about 2,800 m ² /g, more preferably between about 800 m ^{2 /} g g and about 2,500 m ² /g, most preferably between about 1,000 m ² /g and about 2,000 m ² /g. Referring to Fig. 1a, typical nitrogen adsorption isotherms of mesoporous alkaline reduced oxygen wood-based activated carbon (TA4-CA-10) and mesoporous acidic wood-based activated carbon (CA-10) measured by BET method are shown. See Fig. 1b, which shows typical nitrogen adsorption isotherms of mesoporous alkaline wood-based activated carbon (RGC) and mesoporous alkaline reduced oxygen wood-based activated carbon (THe4-RGC) measured by BET method.

During the BET nitrogen adsorption process, the total pore volume of the mesoporous alkaline activated carbon particles can be measured and calculated as the nitrogen adsorption volume when the relative pressure P/Po is equal to 0.9814. More specifically, and as is well known in the art, the total pore volume is calculated by multiplying the "nitrogen adsorption volume in mL(STP)/g" at a relative pressure of 0.9814 by a conversion factor of 0.00156, when STP Convert a volume of nitrogen to a liquid under (standard temperature and pressure) conditions. The filter particles have a total pore volume greater than about 0.4 mL/g, or greater than about 0.7 mL/g, or greater than about 1.3 mL/g, or greater than about 2 mL/g, and/or less than about 3 mL/g, or less than about 2.6 mL /g, or less than about 2mL/g, or less than about 1.5mL/g.

The sum of the mesopore and macropore volumes can be measured during the BET nitrogen adsorption process and calculated as the difference between the total pore volume and the nitrogen adsorption volume when P/Po is equal to 0.15. The sum of the mesopore and macropore volumes of the filter particles may be greater than about 0.12 mL/g, or greater than about 0.2 mL/g, or greater than about 0.4 mL/g, or greater than about 0.6 mL/g, or greater than about 0.75 mL/g , and/or less than about 2.2 mL/g, or less than about 2 mL/g, or less than about 1.5 mL/g, or less than about 1.2 mL/g, or less than about 1 mL/g.

The BJH pore size distribution can be measured using the method of Barrett, Joyner and Halenda (BJH) in J.Amer.Chem.Soc. Vol. 73, pp. 373-380 (1951) and "ADSORPTION, SURFACE AREA, AND POROSITY" (Gregg and Sing, Second Edition, Academic Press, New York 1982), the contents of which are incorporated herein by reference. In one embodiment, for any pore size between about 4 nm and about 6 nm, the pore volume may be at least about 0.01 mL/g. In an alternative embodiment, for any pore size between about 4 nm and about 6 nm, the pore volume may be between about 0.01 mL/g and about 0.04 mL/g. In another embodiment, the pore volume may be at least about 0.03 mL/g, or between about 0.03 mL/g and about 0.06 mL/g for pore sizes between about 4 nm and about 6 nm. In a preferred embodiment, the pore volume may be between about 0.015 mL/g and about 0.06 mL/g for pore sizes between about 4 nm and about 6 nm. Figure 2a illustrates the typical mesoporous volume distributions of the mesoporous basic reduced oxygen activated carbon (TA4-CA-10) and the mesoporous acidic wood-based activated carbon (CA-10) calculated using the BJH method. Figure 2b illustrates the typical mesoporous volume distributions of mesoporous alkaline wood-based activated carbon (RGC) and mesoporous alkaline reduced oxygen wood-based activated carbon (THe4-RGC) calculated using the BJH method.

The ratio of the sum of the mesopore and macropore volumes to the total pore volume is greater than about 0.3, preferably greater than about 0.4, preferably greater than about 0.6, most preferably between about 0.7 and about 1.

The total external surface area is calculated by multiplying the specific external surface area by the filter particle mass and is based on the filter particle size. For example, the specific external surface area of monodisperse (ie, of the same diameter) fibers can be obtained by calculating the ratio of fiber area (neglecting the area of the two cross-sections at the end of the fiber) to fiber weight. Thus, the specific external surface area of the fibers is equal to: 4/Dρ, where D is the fiber diameter and ρ is the fiber density. For monodisperse spherical particles, the specific external area obtained by similar calculation is equal to: 6/Dρ, where D is the particle diameter and ρ is the particle density. For polydisperse fibers, spherical or irregularly shaped particles, the calculation of the specific external surface area is obtained by replacing D with D _3,2 and using the same formulas as above, where D _3,2 is the Sauter average diameter, which is The diameter of a particle whose area-to-volume ratio is the same as that of the entire particle distribution. A method well known in the art for measuring the Sauter mean diameter is laser diffraction, for example using Malvern equipment (available from Malvern Instruments Ltd., Malvern, UK). The specific external area of the filter particles may be between about 10 cm ² /g and about 100,000 cm ² /g, preferably between about 50 cm ² /g and about 50,000 cm ² /g, more preferably between about 100 cm ² /g and about Between 10,000 cm ² /g, most preferably between about 500 cm ² /g and about 7,000 cm ² /g.

The mesoporous, or mesoporous basic, or mesoporous basic oxygen-reducing activated carbon particles may have a BRI value of greater than about 99%, preferably greater than about 99.9%, more preferably greater than about 99.99% when measured in accordance with the test procedure set forth herein , most preferably greater than about 99.999%. This corresponds to mesoporous, or mesoporous basic, or mesoporous basic oxygen reducing activated carbon particles having a BLRI value greater than about 2 log, preferably greater than about 3 log, more preferably greater than about 4 log, most preferably greater than about 5 log. The mesoporous, or mesoporous basic, or mesoporous basic oxygen-reducing activated carbon particles may have a VRI of greater than about 90%, preferably greater than about 95%, more preferably greater than about 99% when measured in accordance with the test procedure set forth herein , most preferably greater than about 99.9%. This corresponds to a VLRI value of the mesoporous, or mesoporous basic, or mesoporous basic reducing oxygen activated carbon particles greater than about 1 log, preferably greater than about 1.3 log, more preferably greater than about 2 log, most preferably greater than about 3 log.

Steady-state, one-dimensional, "clean" bed filtration theory (assuming microbial Dispersive transport and desorption are negligible), incorporated herein by reference, which describe:

C/C _o =exp(-λL) (1)

where C is the effluent concentration, _Co is the influent concentration, λ is the filtration coefficient in units of the reciprocal of the length, and L is the filtration depth. Note that based on the above definition, the number of collisions experienced by non-adhered microorganisms as they flow through a distance L within the filter will be (λ/α)L, where α is the "clean" bed adhesion coefficient (also called Collision rate), which is defined as the ratio of the number of microorganisms adhering to the capture surface to the number of microorganisms colliding with the capture surface. This equation also applies to radial flow filters if L in Equation 1 is replaced by R _o -R _I , where R _o is the outer diameter, R _i is the inner diameter, and the filter coefficient is averaged over the thickness of the filter. The filtration coefficient for a bed containing particles (rather than fibers) is as follows:

λ=(3(1-ε)ηα)/2d _c (2)

where ε is the porosity of the filter bed, η is the single trapping rate, which is defined as the ratio of the number of microorganisms colliding with the trapping surface to the number of microbes flowing to the trapping surface, and _dc is the diameter of the trapped particles. The factor (3/2) in the above formula is valid for spherical or quasi-spherical particles. For cylindrical particles (such as fibers), this term becomes (4/π), then d _c is the diameter of the cylinder. Also, it is to be noted that the term "clean" bed means that the trapping surface has not accumulated sufficient microorganisms to reduce the efficiency of deposition of new microorganisms (ie clogging).

Based on the above "clean" bed filtration model, F-BLR and F-VLR can be calculated as follows:

F-BLR or F-VLR=-log(C/C ₀ )=(λL/2.3) (3)

Using the Rajagopalan and Tien model (RT model; AIChE J., Vol. 22 (No. 3), pp. 523-533 (1976), and AIChE J., Vol. 28, pp. 871-872 (1982) ) Calculate the single capture rate η as follows:

η＝4A _s ^1/3 Pe ^-2/3 +A _s Lo ^1/8 R ^15/8 +0.00338A _s G ^6/5 R ^-2/5 (4)

in

${\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; r</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; r</span>}}^{\mathrm{<span\; class="notranslate">\; 5</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; <figure-callout\; id="6"\; label="r"\; filenames="A0382594600351.png,A0382594600361.png"\; state="\{\{state\}\}">r</figure-callout></span>}}^{\mathrm{<span\; class="notranslate">\; 6</span>}}<span\; class="notranslate">\; ,</span>}$

γ=(1-ε) ^1/3 , Pe is the dimensionless Peclet number

$\mathrm{<span\; class="notranslate">\; Pe</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; \&mu;\&pi;U</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}{\mathrm{<span\; class="notranslate">\; kT</span>}}<span\; class="notranslate">\; ,</span>$

Lo is the dimensionless London-Van der Waals number

$\mathrm{<span\; class="notranslate">\; Lo</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; <figure-callout\; id="9"\; label="h"\; filenames="A0382594600421.png"\; state="\{\{state\}\}">h</figure-callout></span>}}{\mathrm{<span\; class="notranslate">\; 9</span>}\mathrm{<span\; class="notranslate">\; \&pi;\&mu;</span>}{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; u</span>}}<span\; class="notranslate">\; ,</span>$

R is the dimensionless intercept number

$\mathrm{<span\; class="notranslate">\; R</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; c</span>}}}<span\; class="notranslate">\; ,</span>$

G is the dimensionless precipitation number

$\mathrm{<span\; class="notranslate">\; G</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="d\; m"\; filenames="A0382594600351.png,A0382594600361.png"\; state="\{\{state\}\}">d</figure-callout></span><figure-callout\; id="2"\; label="d\; m"\; filenames="A0382594600351.png,A0382594600361.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}^{\mathrm{<span\; class="notranslate">m</span>}}}{\mathrm{<span\; class="notranslate">\; 18</span>}\mathrm{<span\; class="notranslate">\; \&mu;U</span>}}<span\; class="notranslate">\; ,</span>$

μ is the dynamic fluid viscosity (equal to 1mPa·s for water), U is the surface fluid velocity (calculated as: for axial flow filters, U=4Q/πD ² , where Q is the fluid flow rate, D is the frontal area of the filter Diameter; for radial flow filters, U(R)=Q/2πRX, where X is the length of the filter, R is the radial position between R _i and R ₀ ), d _m is the diameter of the microorganism (or if the microorganism is a non- spherical, then it is equivalent to the diameter of a sphere), k is the Boltzmann constant (equal to 1.38×10 ^-23 kg·m ² /s ² ·K), T is the fluid temperature, and H is the Hamaker constant (typically equal to 10 ^-20 J), g is the gravitational constant (equal to 9.81m/s ² ), ρ _m is the density of microorganisms, and ρ _f is the fluid density (equal to 1 g/mL for water). For the purpose and material of the present invention, H is equal to 10 ⁻²⁰ J, T is equal to 298K, ρ _m is equal to 1.05 g/mL, and μ is equal to 1 mPa·s. Also, for purposes of this invention, _dc is the volume median particle diameter Dv, _0.5 , which is the particle diameter at which 50% of the total particle volume is contained within the smaller diameter particle. Also, the average fluid residence time is calculated as:

For axial flow filters,

$\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&epsiv;\&pi;D</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; Q</span>}}<span\; class="notranslate">\; ,</span>$

radial flow filter,

$\mathrm{<span\; class="notranslate">\; \&tau;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&epsiv;\&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="R"\; filenames="A0382594600331.png,A0382594600351.png"\; state="\{\{state\}\}">R</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; x</span>}}{\mathrm{<span\; class="notranslate">\; Q</span>}}$

The coefficient of adhesion, α, is typically calculated experimentally, for example using the "microbe andradiolabel kinesis" (MARK) technique described in Gross et al. (WaterRes., Vol. 29 (No. 4), pp. 1151-1158 (the year 1995)). The single capture rate η of the filter of the present invention may be greater than about 0.002, preferably greater than about 0.02, preferably greater than about 0.2, preferably greater than about 0.4, more preferably greater than about 0.6, and most preferably between about 0.8 and about 1. The filtration coefficient λ of the filter of the present invention may be greater than about 10m ^-1 , preferably greater than about 20m ^-1 , more preferably greater than about 30m ^-1 , most preferably greater than about 40m ^-1 , and/or less than about 20,000m ^-1 , preferably less than About 10,000 m ⁻¹ , more preferably less than about 5,000 m ⁻¹ , most preferably less than about 1,000 m ⁻¹ .

Filters of the present invention comprising mesoporous, or mesoporous basic, or mesoporous basic oxygen-reducing activated carbon particles may have an F-BLR value greater than about 2 log, preferably greater than about 3 log, when measured according to the test procedure set forth herein, More preferably greater than about 4 log, most preferably greater than about 6 log. Filters of the present invention comprising mesoporous, or mesoporous basic, or mesoporous basic oxygen-reducing activated carbon particles may have a F-VLR value of greater than about 1 log, preferably greater than about 2 log, when measured according to the test procedure set forth herein, More preferably greater than about 3 log, most preferably greater than about 4 log.

In a preferred embodiment of the present invention, the filter particles comprise mesoporous activated carbon particles comprising wood-based activated carbon particles. These particles have a BET specific surface area between about 1,000m ² /g and about 2,000m ² /g, a total pore volume between about 0.8mL/g and about 2mL/g, and a sum of mesopore and macropore volume between Between about 0.4 mL/g and about 1.5 mL/g.

In another preferred embodiment of the present invention, the filter particles comprise mesoporous alkaline activated carbon particles comprising wood-based activated carbon particles. These particles have a BET specific surface area between about 1,000m ² /g and about 2,000m ² /g, a total pore volume between about 0.8mL/g and about 2mL/g, and a sum of mesopore and macropore volume between Between about 0.4 mL/g and about 1.5 mL/g.

In another preferred embodiment of the present invention, the filter particles comprise mesoporous basic oxygen-reducing activated carbon particles that are initially acidic but are treated to basic oxygen-reducing carbon under an atmosphere of dissociated ammonia. These granules are wood-based activated carbon granules. The treatment temperature is between about 925°C and about 1,000°C, the ammonia flow rate is between about 1 standard L/hg and about 20 standard L/hg, and the treatment time is between about 10 minutes and about 7 hours. These particles have a BET specific surface area between about 800 m ² /g and about 2,500 m ² /g, a total pore volume between about 0.7 mL/g and about 2.5 mL/g, and a sum of mesopore and macropore volumes between Between about 0.21 mL/g and about 1.7 mL/g. Non-limiting examples of acidic activated carbons converted to basic oxygen-reducing activated carbons are set forth below.

In another preferred embodiment of the present invention, the filter particles comprise mesoporous basic oxygen-reducing activated carbon particles that are initially mesoporous basic and treated with an inert atmosphere (ie, helium). These granules are wood-based activated carbon granules. The processing temperature is between about 800°C and about 1,000°C, the helium flow rate is between about 1 standard L/hg and about 20 standard L/hg, and the processing time is between about 10 minutes and about 7 hours. These particles have a BET specific surface area between about 800 m ² /g and about 2,500 m ² /g, a total pore volume between about 0.7 mL/g and about 2.5 mL/g, and a sum of mesopore and macropore volumes between Between about 0.21 mL/g and about 1.7 mL/g. Non-limiting examples of basic activated carbons converted to basic oxygen-reducing activated carbons are set forth below.

III. Processing Example

Example 1

Treatment of mesoporous acidic activated carbon to prepare mesoporous alkaline reduced oxygen activated carbon

^CARBOCHEM® CA-10 mesoporous acidic wood-based activated carbon particles purchased from Carbochem, Inc. of Ardmore, PA, with a mass of about 2 kg, were placed on a conveyor belt of a model BAC-M furnace operated by a company located in Cranston, RI. Manufactured by CIHayes Inc. The temperature in the furnace is set at about 950°C, the treatment time is about 4 hours, and the atmosphere is dissociated ammonia, which flows at a volume flow rate of about 12,800 standard L/h (ie 450 standard ft ³ /h, or equivalent to about 6.4 Standard L/hg). The treated activated carbon particles are called TA4-CA-10, and its BET isotherm, mesopore volume distribution, and zero-charge point analysis are shown in Figures 1a, 2a, and 3a, respectively. BET values, sum of mesopore and macropore volumes, point of zero charge, BRI/BLRI, VRI/VLRI, bulk oxygen weight percent and oxidation-reduction potential (ORP) are shown in Section VI.

Example 2

Treatment of mesoporous basic activated carbon to prepare mesoporous basic oxygen-reducing activated carbon

MeadWestvaco ^Nuchar® RGC mesoporous alkaline wood-based activated carbon particles with a mass of about 2 kg purchased from MeadWestvaco Corp. of Covington, VA were placed on a model BAC-M furnace conveyor belt operated by CI Hayes Inc. of Cranston, RI. .manufacture. The temperature in the furnace is set at about 800°C, the treatment time is 4 hours, and the atmosphere is helium, which flows at a volume flow rate of about 12,800 standard L/h (ie 450 standard ft ³ /h, or equivalent to about 6.4 standard L /hg). The treated activated carbon particles are called THe4-RGC, and its BET isotherm, mesopore volume distribution, and zero-charge point analysis are shown in Figures 1b, 2b, and 3b, respectively. BET values, sum of mesopore and macropore volumes, point of zero charge, BRI/BLRI, VRI/VLRI, bulk oxygen weight percent and oxidation-reduction potential (ORP) are shown in Section VI.

IV. Filters of the present invention

See Figure 4, which illustrates an exemplary filter made in accordance with the present invention. Filter 20 includes a cylindrical housing 22 having an inlet 24 and an outlet 26 . Housing 22 may be provided in a variety of forms, shapes, sizes and arrangements depending on the intended use and desired performance of filter 20, as is known in the art. For example, filter 20 may be an axial flow filter in which inlet 24 and outlet 26 are positioned such that liquid flows along the axis of housing 22 . Alternatively, filter 20 may be a radial flow filter in which inlet 24 and outlet 26 are arranged such that fluid (eg, liquid, gas, or a mixture thereof) flows radially of housing 22 . Whether in axial flow or radial flow configuration, filter 20 may preferably be configured to provide a frontal area of at ^least about 0.5 in. ² (3.2 cm ² ), more preferably at least about 3 in ^. At least about 5 in. ² (32.2 cm ² ), and the filtration depth is preferably at least about 0.125 in. (0.32 cm), preferably at least about 0.25 in. (0.64 cm), more preferably at least about 0.5 in. (1.27 cm), most Preferably at least about 1.5 in. (3.81 cm). For radial flow filters, the filter length may be at least 0.25 in. (0.64 cm), more preferably at least about 0.5 in. (1.27 cm), and most preferably at least about 1.5 in. (3.81 cm). Still further, the filter 20 may include both an axial flow portion and a radial flow portion.

The housing may also be made as part of another structure without departing from the scope of the present invention. Although the filter of the present invention is particularly suitable for use with water, it should be recognized that it is suitable for use with other fluids (eg, air, gas, and mixtures of gases and liquids). As such, filter 20 is then intended to represent a common liquid or gas filter. The size, shape, spacing, arrangement and location of the inlets 24 and outlets 26 may be selected to suit the flow rate and intended use of the filter 20, as is known in the art. Preferably, the filter 20 is designed for residential or commercial drinking water applications, including, but not limited to, household filters, refrigerator filters, portable water combination components (e.g., camping equipment, such as kettles), faucet-mounted filters, filters under sinks, medical device filters, industrial filters, air filters, etc. Examples of filter configurations, drinking water devices, drinker appliances and other water filtration devices suitable for use in the present invention are disclosed in U.S. Patents 5,527,451; 5,536,394; 5,709,794; 5,882,507; and 6,241,899, which are hereby incorporated by reference. For potable water applications, the filter 20 is preferably configured to have a flow rate of less than about 8 L/min, or less than about 6 L/min, or between about 2 L/min and about 4 L/min, and the filter may contain less than about 2 kg of filtered material, or less than about 1 kg of filter material, or less than about 0.5 kg of filter material. Additionally, for potable water applications, filter 20 may preferably be configured to have an average fluid residence time of at least about 3 seconds, preferably at least about 5 seconds, preferably at least about 7 seconds, more preferably at least about 10 seconds, most preferably at least about 15 seconds. Also, for potable water applications, filter 20 may preferably be configured to have a filter material pore volume of at least about 0.4 cm ³ , preferably at least about 4 cm ³ , more preferably at least about 14 cm ³ , and most preferably at least about 25 cm ³ .

Filter 20 also includes filter material 28 that may be used in conjunction with other filtration systems, including reverse osmosis systems, ultraviolet light systems, ion exchange systems, electrolyzed water systems, and other water treatment systems known to those skilled in the art.

Filter 20 also includes filter material 28, where filter material 28 includes one or more filter particles (eg, fibers, granules, etc.). The one or more filter particles may be mesoporous, more preferably mesoporous basic, most preferably mesoporous basic oxygen-reducing, and have the characteristics previously discussed. The medium pore, or medium pore alkaline, or medium pore alkaline reducing oxygen activated carbon filter material 28 can be combined with particles formed from other materials or material combinations, such as activated carbon powder, activated carbon particles, activated carbon fibers, zeolites, Inorganic substances (including activated alumina, magnesia, diatomaceous earth, silicon dioxide, mixed oxides such as hydrotalcite, glass, etc.), cationic substances (including polymers such as polyamides (polyaminoamides), polyethyleneimine, polyethyleneamine , polydiallyldimethylammonium chloride, polydimethylamine-epichlorohydrin, polyhexamethylene biguanide, can be combined with fibers (including polyethylene, polypropylene, ethylene maleic anhydride copolymer poly-[2-(2-ethoxy)-ethoxyethyl]-guanidine chloride), carbon, glass, etc.), and/or irregularly shaped materials (including carbon, diatomaceous earth, sand , glass, clay, etc.) and their mixtures. Examples of filter materials and combinations of filter materials to which mesoporous alkaline activated carbon may be combined are disclosed in US Patent Nos. 6,274,041, 5,679,248, and US Patent Application Serial No. 09/628,632, also incorporated herein by reference. As previously mentioned, the filter material may be provided in loose or interconnected form (eg, as a unitary structure formed by a polymeric binder or otherwise partially or fully bonded).

By changing the size, shape, complex formation, charge, porosity, surface structure, functional groups, etc. of the above-mentioned filter particles, the filter material can be used for different purposes (such as used as a pre-filter or post-filter). As just described, the filter material can also be mixed with other materials to suit a particular application. Whether or not the filter material is mixed with other materials, it can be used as loose beds, filter blocks (including coextruded blocks as described in US Patent No. 5,679,248, incorporated herein by reference), and mixtures thereof. Preferred methods that can be used for filter materials include forming filter blocks produced by ceramic-carbon hybrids (where the bonding force comes from the firing of the ceramic articles), utilizing the interfacial interactions between the nonwoven materials described in U.S. Patent 6,077,588, incorporated herein by reference. powder, by activating the resin binder forming the filter block using the wet strength method described in U.S. Patent 5,928,588, which is incorporated herein by reference, or by resistance heating method.

V. Filter Embodiment

Example 3

Filters containing mesoporous alkaline activated carbon particles

About 18.3 g of ^Nuchar® RGC mesoporous basic activated carbon powder ( _{Dv, 0.5} equals about 45 μ) from MeadWestvaco Corp. in Covington, VA was mixed with about 7 g of Microthene® from Equistar Chemicals, Inc. in Cincinnati, OH ^. Low density polyethylene (LDPE) FN510-00 binder was mixed with about 2 grams of Alusil(R ⁾ 70 aluminosilicate powder available from Select, Inc. of Norcross, GA. The mixed powder was then poured into a circular aluminum mold having an inner diameter of about 3 in. (about 7.62 cm) and a depth of about 0.5 in. (about 1.27 cm). The mold was sealed and placed in a heated press with rollers at a temperature of about 204°C for 1 hour. Then, the mold was cooled to room temperature, opened, and the axial filter was removed. The filter is characterized by: frontal area: about 45.6 ^cm2 ; depth of filtration: about 1.27 cm; total filter volume: about 58 mL; filter porosity (for pores greater than about 0.1 μm): about 0.43; and filter material Pore volume (for pores larger than about 0.1 μm): about 25 mL (measured by mercury porosimetry). Filters were placed in Teflon ^(R) housings as described in the test procedure below. The filter has a pressure drop of about 17 psi (about 1.2 bar, 0.12 MPa) for about the first 2,000 filter pore volumes at a flow rate of about 200 mL/min. Values for F-BLR, F-VLR, η and α are shown in Section VI.

Example 4

Filters containing microporous alkaline activated carbon particles

About 26.2 g of coconut microporous alkaline activated carbon powder (D _v.0.5 equals about 92 μ) was mixed with 7 g of ^Microthene® low density polyethylene (LDPE) FN510-00 binder purchased from Equistar Chemicals, Inc. located in Cincinnati, OH , and about 2 g of ^Alusil® 70 aluminosilicate powder available from Selecto, Inc. of Norcross, GA. The mixed powder was then poured into a circular aluminum mold having an inner diameter of about 3 in. (about 7.62 cm) and a depth of about 0.5 in. (about 1.27 cm). The mold was sealed and placed in a heated press with rollers at a temperature of about 204°C for 1 hour. Then, the mold was cooled to room temperature, opened, and the axial filter was removed. The filter is characterized by: frontal area: about 45.6 ^cm2 ; depth of filtration: about 1.27 cm; total filter volume: about 58 mL; filter porosity (for pores larger than about 0.1 μm): about 0.44; filter material pores Volume (for pores larger than about 0.1 μm): about 25.5 mL (measured by mercury porosimetry). Filters were placed in Teflon ^(R) housings as described in the test procedure below. The filter has a pressure drop of about 17 psi (about 1.2 bar, about 0.12 MPa) for about the first 2,000 filter pore volumes at a flow rate of about 200 mL/min. Values for F-BLR, F-VLR, η and α are shown in Section VI.

VI. Test and calculation steps

The following test procedure was used to calculate the BET, point of zero charge, BRI/BLRI, VRI/VLRI, bulk oxygen weight percent, oxidation-reduction potential (ORP), F-BLR, and F-VLR values described herein. The paper also describes the calculation procedure for the single capture rate, filtration coefficient, mean fluid residence time and F-BLR value.

Although the BRI/BLRI values and VRI/VLRI values are measured for aqueous media, there is no need to limit the end use of the filter material in the present invention, although the BRI/BLRI values and VRI/VLRI values are calculated for aqueous media, but the filter material can ultimately be used with other fluids Used together as previously described. Furthermore, the filter materials used below are chosen to illustrate the test procedure and do not limit the scope of processing and/or filter material composition in the present invention, nor do they limit the types of filter materials that can be evaluated for use in the present invention when using this test procedure.

BET testing steps

Using nitrogen adsorption techniques (as described in ASTM D 4820-99, the contents of which are incorporated herein by reference) with a Coulter SA3100 Series Surface Area and Pore Size Analyzer manufactured by Coulter Corp. located in Miami, FL at about 77K for multi-point Nitrogen adsorption was used to measure the BET specific surface area and pore volume distribution. The method also yields micropore, mesopore and macropore volumes. For the TA4-CA-10 filter particles in Example 1, the BET area is about 1,038 m ² /g, the micropore volume is about 0.43 mL/g, and the sum of mesopore and macropore volume is about 0.48 mL/g. For the THe4-RGC filter particles in Example 2, the BET area is about 2,031 m ² /g, the micropore volume is about 0.81 mL/g, and the sum of mesopore and macropore volume is about 0.68 mL/g. Note that the respective values of raw material CA-10 and RGC are: about 1,309m ² /g, about 0.54mL/g, about 0.67mL/g; and about 1,745m ² /g, about 0.70mL/g, about 0.61mL/g, respectively g. Typical BET nitrogen isotherms and mesopore volume distributions of the filter materials in Examples 1 and 2 are shown in Figures 1a and 1b, respectively. As is known in the art, it will be appreciated that other instruments may be substituted for BET measurements.

Point of Zero Charge Test Procedure

An approximately 0.010M aqueous solution of KCl can be prepared from reagent grade KCl and water freshly distilled under argon. The water used for distillation is deionized using continuous reverse osmosis and ion exchange. A volume of approximately 25.0 mL of aqueous KCl was divided into six approximately 125 mL flasks, each fitted with a 24/40 ground glass stopper. Microliter amounts of standard aqueous HCl or NaOH solution were added to each flask to give an initial pH range between about 2 and about 12. The pH of each flask was then recorded using an Orion Model 420A pH Meter with an Orion Model 9107BN Triode Combination pH/ATC Electrode manufactured by Thermo Orion Inc. of Beverly, MA, which was referred to as the "Initial pH". pH". About 0.0750 ± 0.0010 g of activated carbon particles were added to each of the six flasks and the aqueous suspension was stirred (at about 150 rpm) at room temperature for about 24 hours before the "final pH" was recorded. Figure 3a shows the initial and final pH values tested with CA-10 and TA4-CA-10 activated carbon materials, and Figure 3b shows the initial and final pH values tested with RGC and The4-RGC activated carbon materials. The points of zero charge of CA-10, TA4-CA-10, RGC, and THe4-RGC were about 5.0, about 9.7, about 8.8, and about 8.6, respectively. It will be appreciated that other instruments may be substituted for this testing step, as is known in the art.

BRI/BLRI test procedure

A PB-900 ^(TM) Programmable JarTester test apparatus manufactured by Phipps & Bird, Inc. of Richmond, VA with 2 or more Pyrex ^(R) glass beakers (depending on the amount of test material) was used. The diameter of the beaker was about 11.4 cm (about 4.5") and the height was about 15.3 cm (about 6"). Each beaker contained approximately 500 mL of municipal supply dechlorinated tap water contaminated with E. coli microorganisms and a stirrer rotating at approximately 60 rpm. The stir bar is a stainless steel blade with a length of about 7.6 cm (about 3"), a height of about 2.54 cm (about 1"), and a thickness of about 0.24 cm (about 3/32"). Place the stir bar at a distance from the beaker About 0.5cm (about 3/16″) from the bottom. The first beaker did not contain any filter material and was used as a control, the other beakers contained sufficient filter material with a Sauter mean diameter of less than about 55 μm such that the total geometrical external area of the material in the beakers was about 1400 cm ² . The Sauter mean diameter is obtained by either: a) sieving a sample with a broad size distribution and high Sauter mean diameter; or b) reducing the size of the filter particles (e.g., if filtering The particle size is greater than about 55 μm, or if the filter material is in integrated or bonded form). For example, and not limitation, size reduction techniques include crushing, grinding, and milling. Typical equipment used for size reduction includes jaw crushers, gyratory crushers, roller crushers, pulverizers, heavy-duty impact mills, mid-size mills, and hydrodynamic mills such as centrifugal ejectors, opposing jets Or injector with an anvil. Size reduction is available for loose or bonded filter particles. Any filter particles or biocide coating should be removed from the filter material prior to testing. Alternatively, uncoated filter particles can be substituted for the test.

Replicate samples of approximately 5 mL per volume of water were collected from each beaker for analysis at various times after the filter particles were added to the beakers until equilibrium was reached in the beaker containing the filter particles. Typical sampling times are: about 0, about 2, about 4 and about 6 hours. Other devices known in the art may be used instead.

The E. coli used was ATCC# 25922 provided by the American Type Culture Collection in Rockville, MD. The target E. coli concentration in the control beaker was set at approximately 3.7 x 10 ⁹ CFU/L. E. coli can be assayed using membrane filtration technology as described in #9222 of "Standard Processes for the Examination of Water and Wastewater," 20th Edition, published by the American Public Health Association (APHA), Washington, DC, the contents of which are incorporated herein for reference. The limit of detection (LOD) was about 1×10 ³ CFU/L.

Exemplary BRI/BLRI results for the filter materials in Examples 1 and 2 are shown in Figures 5a and 5b. The amount of porous acidic activated carbon material in CA-10 was about 0.75 g, and the amount of porous basic oxygen-reducing activated carbon material in TA40-CA-10 was about 0.89 g. The amount of porous basic activated carbon material in RGC was about 0.28 g, and the amount of porous basic oxygen-reducing activated carbon material in THe4-RGC was about 0.33 g. All four quantities correspond to an external surface area of about 1,400 ^cm2 . The E. coli concentration in the control beaker in Figure 5a was about 3.7×10 ⁹ CFU/L, and in Figure 5b was about 3.2×10 ⁹ CFU/L. The concentration of E. coli in the beakers containing CA-10, TA4-CA-10, RGC and THe4-RGC samples reached equilibrium in about 6 hours, and their values were: about 2.1×10 ⁶ CFU/L, about 1.5× 10 ⁴ CFU/L, about 3.4×10 ⁶ CFU/L, and about 1.2×10 ⁶ CFU/L. The respective BRI values were then calculated to be about 99.94%, about 99.9996%, about 99.91%, and about 99.97%, and the respective BLRI values were calculated to be about 3.2 log, about 5.4 log, about 3.0 log, and about 3.5 log.

Test steps for VRI/VIRI

The test equipment and test procedures used are the same as those used to determine the BRI/BLRI value. The first beaker contained no filter material, and as a control, the other beakers contained sufficient filter material with a Sauter mean diameter of less than about 55 μm such that the total geometrical external area in the beaker was about 1400 cm ² . Any filter particles or biocide coating should be removed from the filter material prior to testing. Alternatively, uncoated filter particles or filter material can be substituted for the test.

The MS-2 bacteriophage used was ATCC# 15597B provided by the American Type Culture Collection in Rockville, MD. The target MS-2 concentration in the control beaker was set at approximately 2.07 x ¹⁰⁹ PFU/L. The MS-2 assay can be performed according to the procedure described by CJ Hurst in Appl. Environ. Microbiol., Vol. 60 (No. 9), p. 3462 (1994), the contents of which are incorporated herein by reference. Other assay methods known in the art can also be used instead. The limit of detection (LOD) was about 1 x ¹⁰³ PFU/L.

Exemplary VRI/VLRI results for the filter materials in Examples 1 and 2 are shown in Figures 6a and 6b. The amount of porous acidic activated carbon material in CA-10 was about 0.75 g, and the amount of porous basic oxygen-reducing activated carbon material in TA40-CA-10 was about 0.89 g. The amount of porous basic activated carbon material in RGC was about 0.28 g, and the amount of porous basic oxygen-reducing activated carbon material in THe4-RGC was about 0.33 g. All four quantities correspond to an external surface area of about 1,400 ^cm2 . The MS-2 concentration in the control beaker was about 6.7×10 ⁷ PFU/L in Figure 6a and about 8.0×10 ⁷ PFU/L in Figure 6b. MS-2 concentrations in the beakers containing CA-10, TA4-CA-10, RGC and THe4-RGC samples reached equilibrium within 6 hours, and their values were about 4.1×10 ⁴ PFU/L, about 1×10 ³ PFU/L, about 3×10 ³ PFU/L, and less than about 1.0×10 ³ PFU/L (detection limit). Then, respective VRI values were calculated to be about 99.94%, about 99.999%, about 99.996% and greater than about 99.999%, and respective VLRI values were calculated to be about 3.2 log, about 5 log, about 4.4 log and greater than about 5 log.

Bulk oxygen weight percent test procedure

Bulk oxygen weight percent was measured using a PerkinElmer Model 240 Elemental Analyzer (OxygenModification; PerkinElmer, Inc.; Wellesley, MA). The technique is based on the pyrolysis of samples in a flow of helium at about 1000 °C on platinized carbon. The carbon samples were dried overnight in a vacuum oven at about 100°C. It will be appreciated that other instruments may be substituted for this testing step, as is known in the art. Exemplary bulk oxygen weight percent values for filter materials CA-10, TA4-CA-10, RGC, and THe4-RGC are about 8.3%, about 1.1%, about 2.3%, and about 0.8%, respectively.

Oxidation Reduction Potential (ORP) Test Procedure

Oxidation-reduction potential (ORP) was measured using a platinum redox electrode, model 96-78-00, available from Orion Research, Inc. (Beverly, MA) and following ASTM standard D1498-93. This procedure involves a suspension of about 0.2 g of carbon in about 80 mL of tap water and reading the electrode in mV after about 5 minutes of gentle stirring. It will be appreciated that other instruments may be substituted for this testing step, as is known in the art. Exemplary oxidation reduction potential (ORP) values for filter materials CA-10, TA4-CA-10, RGC, and THe4-RGC are about 427 mV, about 285 mV, about 317 mV, and about 310 mV, respectively.

F-BIR test steps

The housing of the axial flow filter with mesoporous carbon is made of Teflon ^(R) and consists of 2 parts, the cover and the base. Both parts have an outer diameter of about 12.71 cm (about 5") and an inner diameter of about 7.623 cm (about 3"). The lid was seated inversely within the base with an O-ring (approximately 7.623 cm (approximately 3") inner diameter and approximately 0.318 cm (approximately 1/8") compressive stress seal. Use approximately 0.159cm (approximately 1/16″) NPT pipe thread to string the inlet and outlet hose hook and groove connectors into the cover and base. Divide approximately 1.27cm (approximately ″) thick by approximately 6.99cm ( about ") OD stainless steel splitter (with approximately 0.482 cm (approximately 3/16") holes on the upstream side and a screen of approximately 6 meshes on the downstream side) mounted inversely within the cover of the housing. The function of the flow splitter is to distribute the inlet flow on all front sides of the filter. The cover and base of the housing intermesh so that there is a compressive seal sealing the filter within the housing. The cover and base are joined together using four approximately 0.635 (approximately ") fasteners.

A filter was installed in the housing, and water contaminated with about 1×10 ⁸ CFU/L of Escherichia coli passed through the filter at a flow rate of about 200 mL/min. The total amount of water inflow can be about 2,000 filter material pore volumes or more. The E. coli used was ATCC# 25922 provided by the American Type Culture Collection in Rockville, MD. E. coli can be assayed using membrane filtration technology as described in #9222 of "Standard Processes for the Examination of Water and Wastewater," 20th Edition, published by the American Public Health Association (APHA), Washington, DC, which is incorporated herein by reference. for reference. Other assays known in the art may be used instead (eg ^COLILERT® ). The limit of detection (LOD) was about 1 x ¹⁰² CFU/L when measured with the membrane filtration technique and about 10 CFU/L when measured with the ^COLILERTO® technique. After the water has passed through approximately the first 2,000 filter material pore volumes, the effluent water is collected and assayed to enumerate the presence of E. coli bacteria, and the F-BLR value is calculated using the definition.

Exemplary results for calculating F-BLR values for the axial flow filters of Example 3 and Example 4 are shown in Figure 7a. The flow rate used in Figure 7a was about 200 mL/min, and the influent concentration of E. coli varied between about 1 x ¹⁰⁸ and about 1 x ¹⁰⁹ CFU/L. The filter was tested weekly (every Tuesday) with approximately 20 L and the effluent was assayed as described above. The average fluid residence time for the RGC filter was about 7.5 s and for the coconut filter was about 7.65 s. The F-BLR value of the RGC filter in Example 3 was calculated to be about 6.8 log. For the coconut filter in Example 4, the collection of effluent water stopped at about 40 L (which corresponds to about 1,570 filter material pore volumes) because the filter showed almost complete breakthrough at this water volume. At about 1,570 filter material pore volumes, the F-BLR value was calculated to be about 1.9 log.

F-VIR test steps

The housing of the axial flow filter with mesoporous carbon is the same as described above in the F-BLR step. Water contaminated with about 1 x ¹⁰⁷ PFU/L MS-2 was passed through the housing/filter system at a flow rate of about 200 mL/min. The total amount of water inflow is about 2,000 filter material pore volumes or more. The MS-2 bacteriophage used was ATCC# 15597B provided by the American Type Culture Collection in Rockville, MD. The MS-2 assay can be performed according to the procedure described in CJ Hurst, Appl. Environ. Microbiol., Vol. 60 (No. 9), p. 3462 (1994), the contents of which are incorporated herein by reference. Other assay methods known in the art can also be used instead. The limit of detection (LOD) was 1×10 ³ PFU/L. After the water has passed through approximately the first 2,000 pore volumes of the filter material, the effluent water is collected and assayed to enumerate the presence of MS-2 bacteriophage, and the F-VLR value is calculated using the definition.

Exemplary results for calculating F-VLR values for the axial flow filters of Example 3 and Example 4 are shown in Figure 7b. The flow rate used in Figure 7b was about 200 mL/min, and the influent concentration of MS-2 varied around about 1 x ¹⁰⁷ PFU/L. The filter was tested weekly (every Tuesday) with approximately 20 L and the effluent was assayed as described above. The F-VLR value of the RGC filter in Example 3 was calculated to be greater than about 4.2 log. For the coconut filter in Example 4, the collection of effluent water stopped at about 40 L (which equated to about 1,570 filter material pore volumes) because the filter showed almost complete breakthrough at this water volume. At about 1,570 filter material pore volumes, the F-BLR value is calculated to be about 0.3 log.

Calculation steps of single capture rate, filtration coefficient, average fluid residence time and F-BLR value

The single capture rate of the filter was calculated using Equation 4, and the dimensionless number is described after the equation. Exemplary calculations were performed for the axial flow RGC filter in Example 3 using the following parameters: ε = 0.43, d _m , = 1 μm, d _c = 45 μm, H = 10 ⁻²⁰ J, ρ _m , = 1.058 g/mL , ρ _f =1.0g/mL, μ=1mPa·s, T=298K, water flow rate Q=200mL/min, filter diameter D=7.623cm, U=0.0007m/s, given η=0.01864. The parameters are the same and α=1, the filter coefficient can be calculated according to Formula 2 as: λ=354.2m ⁻¹ . Furthermore, the F-BLR value of the same filter can be calculated to be about 1.95log according to Equation 3. Similar exemplary calculations were performed for the coconut filter in Example 4 using the same parameters as above, given η = 0.00717 and λ = 65.5m ^-1 . Finally, the F-BLR value of the same filter can be calculated to be about 0.36log according to Equation 3.

The present invention may additionally include information that will inform the consumer, through text and/or graphics, that the use of the carbon filter particles and/or filter material of the present invention will provide beneficial effects including the removal of microorganisms, and that the information may include superiority over other filter products. claims. In a highly desirable variation, this information may include the use of the present invention to reduce the content of nano-sized microorganisms. Therefore, it is important to use a package with information that will inform the consumer, either textually and/or pictorially, that utilizing the present invention will provide benefits such as drinking water, more potable water, etc. as described herein. This information may include advertisements as in all normal media as well as instructions and icons on the packaging or on the filter itself to inform consumers.

The embodiments of the invention were chosen and described in order to best illustrate the principles of the invention and its practical application, thereby enabling others of ordinary skill in the art to employ the invention in various embodiments and to adapt it to a particular application. Various modifications are contemplated. All such modifications and changes are within the scope of the invention as defined in the appended claims when interpreted in accordance with the principles of fairness, legality and equality to the extent granted.

Claims (21)

1. method of making filtering material said method comprising the steps of:

(a) provide first material, wherein said first material comprises a plurality of mesoporositys activated carbon filtration particle; With

(b) handle described first material to prepare second material, described second material comprises a plurality of mesoporositys activated carbon filtration particle, and described a plurality of mesoporositys activated carbon filtration particulate body oxygen weight percent of wherein said second material is less than about 5%.

2. the method for claim 1, wherein said treatment step (b) comprise described a plurality of mesoporositys activated carbon filtration particle are exposed under the temperature between about 600 ℃ and about 1,200 ℃.

3. the method for claim 1, described a plurality of mesoporositys activated carbon filtration particulate point of zero electric charge of wherein said second material is greater than about 6.

4. the method for claim 1, described a plurality of mesoporosity activated carbon filtration particulate redox potentials (ORP) of wherein said second material are less than about 400mV.

5. the method for claim 1, described a plurality of mesoporositys activated carbon filtration particulate body oxygen weight percent of wherein said second material is less than about 2%.

6. the method for claim 1, wherein said method also comprises inserting step (c), described inserting step (c) is made up of to filter housing the described a plurality of mesoporositys activated carbon filtration particle that inserts described second material, and described shell has water inlet and water out.

7. the method for claim 1, described a plurality of mesoporositys activated carbon filtration particulate BRI value of wherein said second material is greater than about 99%.

8. the method for claim 1, described a plurality of mesoporositys activated carbon filtration particulate VRI value of wherein said second material is greater than about 90%.

9. method of making filtering material said method comprising the steps of:

(a) provide first material, wherein said first material comprises a plurality of mesoporositys activated carbon filtration particle; With

(b) handle described first material to prepare second material, described second material comprises a plurality of mesoporositys activated carbon filtration particle, and described a plurality of mesoporositys activated carbon filtration particulate body oxygen weight percent of wherein said second material is less than about 2.3%.

10. method as claimed in claim 9, wherein said treatment step (b) comprises processing atmosphere, described processing atmosphere is selected from hydrogen, DA, carbon monoxide, argon, nitrogen, steam, helium and their mixture.

11. method as claimed in claim 9, wherein said treatment step (b) comprise the temperature between about 600 ℃ and about 1,200 ℃.

12. method as claimed in claim 9, wherein said treatment step (b) comprise the temperature between about 100 ℃ and about 800 ℃, and wherein said a plurality of mesoporositys activated carbon filtration particle comprises noble metal catalyst.

13. method as claimed in claim 9, described a plurality of mesoporositys activated carbon filtration particulate point of zero electric charge of wherein said second material is between about 9 and about 12.

14. method as claimed in claim 9, described a plurality of mesoporosity activated carbon filtration particulate redox potentials (ORP) of wherein said second material are between about 290mV and about 175mV.

15. method as claimed in claim 9, described a plurality of mesoporositys activated carbon filtration particulate body oxygen weight percent of wherein said second material is between about 1.2% and about 0.1%.

16. a method of making filtering material said method comprising the steps of:

(a) supply raw materials;

(b) handle described raw material to prepare first material, described first material comprises a plurality of mesoporositys activated carbon filtration particle; With

(c) handle described first material to prepare second material, described second material comprises a plurality of mesoporositys activated carbon filtration particle, and described a plurality of mesoporositys activated carbon filtration particulate body oxygen weight percent of wherein said second material is less than about 5%.

17. method as claimed in claim 16, wherein said raw material to small part comprises wooden basic particle, coal-based granular, mud coal base particle, asphaltic base particle, tar base particle, beans base particle, other wood fibre based particle and their mixture, wherein said treatment step (b) comprises described raw material is exposed under the temperature between about 300 ℃ and about 600 ℃, and wherein said treatment step (c) comprises that the described a plurality of mesoporositys activated carbon filtration particle with described first material is exposed under the temperature between 600 ℃ and about 1200 ℃.

18. method as claimed in claim 17, wherein said method also are included in described a plurality of mesoporositys activated carbon filtration particle that described treatment step (c) washs described first material before.

19. method as claimed in claim 18, wherein said treatment step (b) comprises and exposes about 1 hour of described raw material to about 3 hours time, and wherein said treatment step (c) comprises about 1 hour of the described a plurality of mesoporositys activated carbon filtration particle about 6 hours time extremely that exposes described first material.

20. method as claimed in claim 19, wherein said treatment step (b) comprise the existence of acid, described acid is selected from phosphoric acid, zinc chloride, ammonium phosphate and their mixture.

21. a method of making filtering material said method comprising the steps of:

(a) provide first material, wherein said first material comprises a plurality of mesoporositys activated carbon filtration particle; With

(b) handle described first material to prepare second material, described second material comprises a plurality of mesoporositys alkalescence activated carbon filtration particle, described a plurality of mesoporositys alkalescence activated carbon filtration particulate body oxygen weight percent of wherein said second material is less than about 2.3%, mesopore and macropore volume sum are greater than about 0.6mL/g, point of zero electric charge is greater than about 8, redox potential (ORP) is less than about 325mV, and the BRI value is greater than about 99.9%, and the VRI value is greater than about 99.99%.

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