PFAS removal materials, adsorption filters, water purifier cartridges, water purifiers and water purification equipment

Abstract

To provide carbonaceous materials, PFAS removal materials, adsorption filters, water purifier cartridges, water purifiers, and water purification equipment that have excellent durability and PFAS removal performance. [Solution] The pore volume of a carbonaceous material is determined by the CI method from an N2 adsorption isotherm at -196°C. The ratio ((A) / (B)) of the volume of pores with a pore diameter of 2 to 4 nm to the volume of pores with a pore diameter of 1.2 nm or less (A) is 0.085 or more and 0.410 or less. The ratio ((C) / (B)) of the volume of pores with a pore diameter of 9 to 25 nm to the volume of pores with a pore diameter of 1.2 nm or less (C) is 0.04 or more and 0.45 or less.

Description

[Technical Field]

[0001] The present invention relates to a carbonaceous material, a PFAS removal material, an adsorption filter, a water purifier cartridge, a water purifier, and a water purification facility. [Background technology]

[0002] Various industrial fields have demanded PFAS removal materials for removing organic fluorine compounds (perfluoroalkyl compounds and polyfluoroalkyl compounds (hereinafter referred to as PFAS)). For example, PFAS adsorbents capable of adsorbing PFAS have been proposed as PFAS removal materials, and more specifically, carbonaceous materials with micropores have been proposed.

[0003] As a carbonaceous material, for example, fibrous activated carbon obtained by the following method has been proposed: First, coal pitch-based carbon fiber and an alkali activator are mixed, and the mixture is heated under a nitrogen atmosphere to obtain alkali-activated carbon. Next, the alkali-activated carbon is washed, dried, and heat-treated to produce the fibrous activated carbon. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2024 / 180739 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, carbonaceous materials are required to have better durability and better PFAS removal performance.

[0006] The present invention relates to a carbonaceous material having excellent durability and PFAS removal performance, a PFAS removal material, an adsorption filter, a water purifier cartridge, a water purifier, and water purification equipment. [Means for solving the problem]

[0007] The present invention [1] includes a carbonaceous material in which, in the pore volume determined by the CI method from an N2 adsorption isotherm at -196°C, the ratio ((A) / (B)) of the volume of pores having a pore diameter of 2 to 4 nm to the volume of pores having a pore diameter of 1.2 nm or less is 0.085 or more and 0.410 or less, and the ratio ((C) / (B)) of the volume of pores having a pore diameter of 9 to 25 nm to the volume of pores having a pore diameter of 1.2 nm or less is 0.04 or more and 0.45 or less.

[0008] The present invention [2] has a specific surface area of ​​900 m2 or less, determined by the BET method from the N2 adsorption isotherm at -196°C. 2 / g or more 1760m 2 / g or less, the volume of pores (A) having a pore diameter of 2 to 4 nm is 0.030 mL / g or more and 0.100 mL / g or less, the volume of pores (B) having a pore diameter of 1.2 nm or less is 0.230 mL / g or more and 0.350 mL / g or less, and the volume of pores (C) having a pore diameter of 9 to 25 nm is 0.011 mL / g or more and 0.140 mL / g or less.

[0009] The present invention [3] includes the carbonaceous material according to the above [1] or [2], which has an MS hardness of 80.0% or more.

[0010] The present invention [4] includes the carbonaceous material according to any one of the above [1] to [3], which has an average particle size of 0.15 mm or more and 1.70 mm or less.

[0011] The present invention [5] includes the carbonaceous material according to any one of the above [1] to [4], in which the pentavalent value of Reactive Black is 2.0 g / L or more and 15.0 g / L or less.

[0012] The present invention [6] includes the carbonaceous material according to any one of the above [1] to [5], which has a packing density of 0.350 g / mL or more and 0.550 g / mL or less.

[0013] The present invention [7] includes a PFAS removal material containing the carbonaceous material according to any one of the above [1] to [6].

[0014] The present invention [8] includes an adsorption filter containing the carbonaceous material according to any one of the above [1] to [6].

[0015] The present invention [9] includes a water purifier cartridge containing the carbonaceous material according to any one of the above [1] to [6].

[0016] The present invention

[10] includes a water purifier containing the carbonaceous material according to any one of the above [1] to [6].

[0017] The present invention

[11] includes a water purification facility containing the carbonaceous material according to any one of the above [1] to [6]. [Effects of the Invention]

[0018] The carbonaceous material of the present invention has excellent durability and excellent PFAS removal performance.

[0019] The PFAS removal material, adsorption filter, water purifier cartridge, water purifier, and water purification equipment of the present invention contain the above-mentioned carbonaceous material, and therefore the above-mentioned PFAS removal material, adsorption filter, water purifier cartridge, water purifier, and water purification equipment have excellent durability and excellent PFAS removal performance. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 shows a schematic side view of a rotary kiln. [Figure 2] FIG. 2 shows a schematic cross-sectional view of a rotary kiln. [Figure 3] FIG. 3 shows the vessel used to measure MS hardness. DETAILED DESCRIPTION OF THE INVENTION

[0021] 1.Carbonaceous material (1) First embodiment In the first embodiment, the carbonaceous material contains a carbide (described later) obtained by carbonizing a raw material component (described later), as will be described in detail later.

[0022] Carbonaceous materials have pores. The pores of carbonaceous materials are classified based on the pore diameter (pore size) in accordance with the standards of IUPAC (International Union of Pure and Applied Chemistry). More specifically, pores with a pore diameter of less than 2.0 nm are micropores. Pores with a pore diameter of 2.0 nm or more and 50.0 nm or less are mesopores. Pores with a pore diameter of more than 50.0 nm are macropores.

[0023] Mesopores are larger pores than micropores, making them effective for adsorption of PFAS (discussed below), which have relatively large molecular sizes.

[0024] On the other hand, PFAS (described below) may contain multiple types of compounds with different molecular sizes (e.g., PFOA (described below) and PFOS (described below)). Therefore, simply having pores with a pore diameter of 2.0 nm or more and 50.0 nm or less (mesopores) may not be enough to provide sufficient PFAS adsorption performance.

[0025] Therefore, in the first embodiment, the specific surface area and pore volume of the carbonaceous material are adjusted from the viewpoint of achieving both PFAS adsorption performance and durability of the carbonaceous material.

[0026] In other words, in the first embodiment, the carbonaceous material has a predetermined specific surface area and a predetermined pore volume. More specifically, in the first embodiment, the specific surface area of ​​the carbonaceous material is adjusted to a predetermined range, the volume of pores with a pore diameter of 2 to 4 nm (A) is adjusted to a predetermined range, the volume of pores with a pore diameter of 1.2 nm or less (B) is adjusted to a predetermined range, and the volume of pores with a pore diameter of 9 to 25 nm (C) is adjusted to a predetermined range. Each of these is described in detail below.

[0027] [Specific surface area] The specific surface area is the specific surface area determined by the BET method from an N adsorption isotherm at −196° C. (hereinafter referred to as BET specific surface area). The BET specific surface area is used, for example, as an index of the adsorption capacity of a carbonaceous material. The BET specific surface area can be determined in accordance with the examples described later.

[0028] The BET specific surface area of ​​the carbonaceous material is set to 900 m from the viewpoint of ensuring an adsorption area. 2 / g or more, preferably 1000m 2 / g or more, more preferably 1200m 2 / g or more. From the viewpoint of controlling the pore size of the carbonaceous material, the BET specific surface area of ​​the carbonaceous material is, for example, 1760 m 2 / g or less. That is, the BET specific surface area of ​​the carbonaceous material is 900 m 2 / g or more 1760m 2 / g or less, preferably 1000m 2 / g or more 1760m 2 / g or less, more preferably 1200m 2 / g or more 1760m 2 / g or less.

[0029] [Pore volume] The pore volume is determined by the Cranston-Inkley (CI) method from the N adsorption isotherm at -196°C. More specifically, the pore volume of each section (each pore diameter) is calculated by the CI method. The total pore volume of the carbonaceous material is calculated as the sum of the pore volumes of each section (each pore diameter). The pore volume can be determined in accordance with the examples described below.

[0030] [Pore volume of pores with diameters of 2 to 4 nm (A)] The carbonaceous material has pores with a pore diameter of 2 nm or more and 4 nm or less (hereinafter referred to as pores with a pore diameter of 2 to 4 nm).

[0031] In a carbonaceous material, the cumulative pore volume of pores with pore diameters of 2 to 4 nm contained in 1 g of the carbonaceous material (hereinafter referred to as the pore volume (A) of pores with pore diameters of 2 to 4 nm) is adjusted to a predetermined range from the viewpoint of achieving both PFAS (particularly PFOA (described later)) adsorption performance and durability of the carbonaceous material.

[0032] More specifically, in the pore volume (hereinafter the same) determined by the CI method from the N adsorption isotherm at −196° C., the volume (A) of pores with diameters of 2 to 4 nm is 0.030 mL / g or more, preferably 0.040 mL / g or more, more preferably 0.050 mL / g or more, and even more preferably 0.060 mL / g or more. Also, the volume (A) of pores with diameters of 2 to 4 nm is 0.100 mL / g or less, preferably 0.098 mL / g or less, more preferably 0.095 mL / g or less, and even more preferably 0.090 mL / g or less. That is, the pore volume (A) of pores with diameters of 2 to 4 nm is 0.030 mL / g or more and 0.100 mL / g or less, preferably 0.040 mL / g or more and 0.098 mL / g or less, more preferably 0.050 mL / g or more and 0.095 mL / g or less, and even more preferably 0.060 mL / g or more and 0.090 mL / g or less.

[0033] [Volume of pores with diameters of 1.2 nm or less (B)] The carbonaceous material has pores with a pore diameter of 1.2 nm or less (hereinafter referred to as pores with a pore diameter of 1.2 nm or less).

[0034] In a carbonaceous material, the cumulative pore volume of pores with a pore diameter of 1.2 nm or less contained in 1 g of the carbonaceous material (hereinafter referred to as the pore volume (B) of pores with a pore diameter of 1.2 nm or less) is adjusted to a predetermined range from the viewpoint of achieving both PFAS (particularly PFOA (described below) and PFOS (described below)) adsorption performance and durability of the carbonaceous material.

[0035] More specifically, in the pore volume (hereinafter the same) determined by the CI method from the N adsorption isotherm at -196°C, the pore volume (B) of pores with a diameter of 1.2 nm or less is 0.230 mL / g or more, preferably 0.250 mL / g or more, more preferably 0.270 mL / g or more, and even more preferably 0.280 mL / g or more. Also, the pore volume (B) of pores with a diameter of 1.2 nm or less is 0.350 mL / g or less, preferably 0.340 mL / g or less, more preferably 0.330 mL / g or less, and even more preferably 0.320 mL / g or less. That is, the pore volume (B) of pores with a diameter of 1.2 nm or less is 0.230 mL / g or more and 0.350 mL / g or less, preferably 0.250 mL / g or more and 0.340 mL / g or less, more preferably 0.270 mL / g or more and 0.330 mL / g or less, and even more preferably 0.280 mL / g or more and 0.320 mL / g or less.

[0036] If the pore volume (B) of pores with diameters of 1.2 nm or less falls within the above range, competition between PFAS and adsorbates other than PFAS can be suppressed, and the decrease in the amount of PFAS adsorbed onto the carbonaceous material can be suppressed, resulting in efficient adsorption of PFAS.

[0037] [Pore volume (C) of pores with diameters of 9 to 25 nm] The carbonaceous material has pores with a pore diameter of 9 nm or more and 25 nm or less (hereinafter referred to as pores with a pore diameter of 9 to 25 nm).

[0038] In a carbonaceous material, the cumulative pore volume of pores with pore diameters of 9 to 25 nm contained in 1 g of the carbonaceous material (hereinafter referred to as the pore volume (C) of pores with pore diameters of 9 to 25 nm) is adjusted to a predetermined range from the viewpoint of achieving both PFAS (particularly PFOS (described later)) adsorption performance and durability of the carbonaceous material.

[0039] More specifically, in the pore volume (hereinafter the same) determined by the CI method from the N adsorption isotherm at −196° C., the volume (C) of pores with diameters of 9 to 25 nm is 0.011 mL / g or more, preferably 0.015 mL / g or more, more preferably 0.020 mL / g or more, and even more preferably 0.025 mL / g or more. Also, the volume (C) of pores with diameters of 9 to 25 nm is 0.140 mL / g or less, preferably 0.100 mL / g or less, more preferably 0.090 mL / g or less, and even more preferably 0.080 mL / g or less. That is, the pore volume (C) of pores with diameters of 9 to 25 nm is 0.011 mL / g or more and 0.140 mL / g or less, preferably 0.015 mL / g or more and 0.100 mL / g or less, more preferably 0.020 mL / g or more and 0.090 mL / g or less, and even more preferably 0.025 mL / g or more and 0.080 mL / g or less.

[0040] [Action and effect] The carbonaceous material has excellent durability and excellent PFAS removal performance. More specifically, if the carbonaceous material has the above-mentioned specific surface area and pore volumes (A) to (C), the carbonaceous material can have excellent PFOA adsorption performance, excellent PFAS adsorption performance, and excellent durability.

[0041] In the first embodiment, the carbonaceous material is not particularly limited in pore volume ratio (described later) as long as it has the above-mentioned specific surface area and the above-mentioned pore volumes (A) to (C).

[0042] (2) Second embodiment In the second embodiment, the carbonaceous material contains a carbide (described later) obtained by carbonizing a raw material component (described later), similarly to the first embodiment. Unless otherwise specified below, the carbonaceous material of the second embodiment is the same as the carbonaceous material of the first embodiment.

[0043] In the second embodiment, the ratio of the above-mentioned pore volumes of the carbonaceous material (hereinafter referred to as the pore volume ratio) is adjusted from the viewpoint of achieving both the PFAS adsorption performance and the durability of the carbonaceous material.

[0044] In other words, in the second embodiment, the carbonaceous material has a predetermined pore volume ratio. More specifically, in the second embodiment, the ratio ((A) / (B)) of the volume of pores having a pore diameter of 2 to 4 nm to the volume of pores having a pore diameter of 1.2 nm or less (B) is adjusted to be within a predetermined range, and the ratio ((C) / (B)) of the volume of pores having a pore diameter of 9 to 25 nm to the volume of pores having a pore diameter of 1.2 nm or less is adjusted to be within a predetermined range. Each of these is described in detail below.

[0045] [Pore volume ratio (A) / (B)] In the carbonaceous material, the ratio ((A) / (B)) of the volume of pores (A) having a pore diameter of 2 to 4 nm to the volume of pores (B) having a pore diameter of 1.2 nm or less is adjusted, particularly from the viewpoint of achieving both PFOA (described below) adsorption performance and durability of the carbonaceous material.

[0046] Specifically, the ratio ((A) / (B)) of the volume of pores (A) having a diameter of 2 to 4 nm to the volume of pores (B) having a diameter of 1.2 nm or less is 0.085 or more, preferably 0.150 or more, and more preferably 0.250 or more. Furthermore, the ratio ((A) / (B)) of the volume of pores (A) having a diameter of 2 to 4 nm to the volume of pores (B) having a diameter of 1.2 nm or less is 0.410 or less, preferably 0.350 or less, and more preferably 0.310 or less. That is, the ratio ((A) / (B)) of the volume of pores (A) having a diameter of 2 to 4 nm to the volume of pores (B) having a diameter of 1.2 nm or less is 0.085 or more and 0.410 or less, preferably 0.150 or more and 0.350 or less, and more preferably 0.250 or more and 0.310 or less.

[0047] [Pore volume ratio (C) / (B)] In the carbonaceous material, the ratio of the volume of pores (C) having a pore diameter of 9 to 25 nm to the volume of pores (B) having a pore diameter of 1.2 nm or less (pore volume ratio (C) / (B)) is adjusted, particularly from the viewpoint of achieving both PFOS (described below) adsorption performance and durability of the carbonaceous material.

[0048] The ratio ((C) / (B)) of the volume of pores (C) having a diameter of 9 to 25 nm to the volume of pores (B) having a diameter of 1.2 nm or less is 0.04 or more, preferably 0.08 or more, and more preferably 0.10 or more. The ratio ((C) / (B)) of the volume of pores (C) having a diameter of 9 to 25 nm to the volume of pores (B) having a diameter of 1.2 nm or less is 0.45 or less, preferably 0.40 or less, and more preferably 0.35 or less. That is, the ratio ((C) / (B)) of the volume of pores (C) having a diameter of 9 to 25 nm to the volume of pores (B) having a diameter of 1.2 nm or less is 0.04 or more and 0.45 or less, preferably 0.08 or more and 0.40 or less, and more preferably 0.10 or more and 0.35 or less.

[0049] [Pore volume ratio (C) / (A)] In the carbonaceous material, the ratio of the volume (C) of pores having a diameter of 9 to 25 nm to the volume (A) of pores having a diameter of 2 to 4 nm (pore volume ratio (C) / (A)) is not particularly limited and may be adjusted appropriately depending on the purpose and application.

[0050] The ratio of the volume of pores (C) having a diameter of 9 to 25 nm to the volume of pores (A) having a diameter of 2 to 4 nm is, for example, 0.100 or more, preferably 0.200 or more. The ratio of the volume of pores (C) having a diameter of 9 to 25 nm to the volume of pores (A) having a diameter of 2 to 4 nm is, for example, 2.000 or less, preferably 1.000 or less. That is, the ratio of the volume of pores (C) having a diameter of 9 to 25 nm to the volume of pores (A) having a diameter of 2 to 4 nm is, for example, 0.100 or more and 2.000 or less, preferably 0.200 or more and 1.000 or less.

[0051] [Action and effect] The carbonaceous material has excellent durability and excellent PFAS removal performance. More specifically, when the pore volume ratio (A) / (B) and the pore volume ratio (C) / (B) of the carbonaceous material are within the above ranges, the carbonaceous material can have excellent PFOA adsorption performance, excellent PFAS adsorption performance, and excellent durability.

[0052] In the second embodiment, the carbonaceous material is not particularly limited in terms of the specific surface area and each of the pore volumes (A) to (C) as long as it has the above-mentioned pore volume ratios (A) / (B) and (C) / (B).

[0053] That is, in the second embodiment, the specific surface area and each of the pore volumes (A) to (C) of the carbonaceous material may be within the above ranges (i.e., the ranges of the specific surface area and each of the pore volumes (A) to (C) of the carbonaceous material in the first embodiment), or may not be within the above ranges. Preferably, in the second embodiment, the specific surface area and each of the pore volumes (A) to (C) are within the above ranges.

[0054] (3) Physical properties [shape] The shape of the carbonaceous material of the first and second embodiments (hereinafter collectively referred to as carbonaceous material) is not particularly limited, and examples thereof include particles, blocks, rods, pellets, substrates, sheets, and blocks. Examples of rods include cylinders, elliptical cylinders, elliptical truncated cones, and polygonal prisms, and examples of polygonal prisms include triangular prisms, quadrangular prisms, pentagonal prisms, and hexagonal prisms. Examples of pellets include honeycomb pellets and hollow pellets. A preferred shape of the carbonaceous material is particles. Examples of particles include powders, spheres, and crushed chips, and crushed chips are preferred.

[0055] Examples of the powdered form include fine powder, powder, fine particles, and granules. The powdered carbonaceous material is preferably used, for example, as an adsorbent used in batches in batch processing. The powdered carbonaceous material is also preferably used, for example, as a raw material for a molded body.

[0056] The spherical carbonaceous material, for example, has a plurality of particles with a substantially uniform shape, each particle having a shape close to a perfect sphere. The crushed chip-like carbonaceous material, for example, has a plurality of particles with a non-uniform shape, each particle having an arbitrary shape with corners. The spherical carbonaceous material and the crushed chip-like carbonaceous material are preferably used as adsorbents that are continuously used, for example, in column-type treatment and flow-through treatment. More specifically, the spherical carbonaceous material and the crushed chip-like carbonaceous material are preferably used in adsorption filters for water purifiers (described below) and water purification equipment (described below).

[0057] [Particle size] If the carbonaceous material is particulate, the 50% particle diameter of the cumulative volume distribution (D 50 ) is, for example, 1 μm or more and 150 μm or less. 50 ) is measured as a volume-based median diameter using a laser diffraction light scattering particle size distribution measuring device (the same applies below).

[0058] Furthermore, when the carbonaceous material is particulate, the average particle size (representative diameter) of the carbonaceous material is, for example, 0.15 mm or more, preferably 0.20 mm or more. The average particle size (representative diameter) of the carbonaceous material is, for example, 1.70 mm or less, preferably 1.50 mm or less. That is, the average particle size (representative diameter) of the carbonaceous material is, for example, 0.15 mm or more and 1.70 mm or less, preferably 0.20 mm or more and 1.50 mm or less.

[0059] If the average particle size of the carbonaceous material is within the above range, even better adsorption performance can be obtained. That is, when the carbonaceous material is used in a liquid (such as treated water), if the average particle size of the carbonaceous material is equal to or greater than the above lower limit, pressure loss during liquid passage can be suppressed. Furthermore, if the average particle size of the carbonaceous material is equal to or less than the above upper limit, the contact area between the carbonaceous material and the liquid can be increased. Therefore, if the average particle size of the carbonaceous material is within the above range, even better adsorption performance can be obtained.

[0060] The average particle size (representative diameter) has the same meaning as the mass average particle size in JIS K 1474 (2014). That is, the average particle size (representative diameter) of the carbonaceous material is calculated according to the calculation method for mass average particle size in JIS K 1474 (2014).

[0061] [Sphericity] When the carbonaceous material is spherical, the sphericity (longest diameter / shortest diameter) of the carbonaceous material is, for example, 1.00 or more and 1.10 or less, preferably 1.00 or more and 1.09 or less, and more preferably 1.02 or more and 1.08 or less.

[0062] The sphericity (longest diameter / shortest diameter) can be determined from an image taken with a digital microscope.

[0063] [Mechanical strength (MS hardness)] The carbonaceous material preferably has a relatively high MS (microstrength) hardness.

[0064] The MS hardness of the carbonaceous material is, for example, 80.0% or more, preferably 85.0% or more, more preferably 90.0% or more, and particularly preferably 95.0% or more. The MS hardness of the carbonaceous material is, for example, 100.0% or less. That is, the MS hardness of the carbonaceous material is, for example, 80.0% or more and 100.0% or less, preferably 85.0% or more and 100.0% or less, more preferably 90.0% or more and 100.0% or less, and particularly preferably 95.0% or more and 100.0% or less.

[0065] If the MS hardness of the carbonaceous material is within the above range, even better durability can be obtained. That is, when the carbonaceous material is used in a liquid (such as treated water), the carbonaceous material may come into contact with itself as the liquid flows. In such a case, if the MS hardness of the carbonaceous material is equal to or greater than the above lower limit, the generation of fine powder due to contact between carbon fibers can be suppressed. As a result, clogging by fine powder can be suppressed in a filter arranged downstream of the carbonaceous material. Furthermore, if the MS hardness of the carbonaceous material is within the above range, the granulation of the carbonaceous material due to the above contact can be suppressed, and an increase in the packing rate of the carbonaceous material can be suppressed, and as a result, an increase in pressure loss during liquid passage can be suppressed. That is, if the MS hardness of the carbonaceous material is within the above range, the frequency of replacement of the carbonaceous material can be reduced. As a result, particularly excellent durability can be obtained.

[0066] The MS hardness is measured in accordance with the examples described below.

[0067] [Filling density] The carbonaceous material preferably has a packing density within a range.

[0068] The packing density of the carbonaceous material is, for example, 0.350 g / mL or more, preferably 0.400 g / mL or more, and more preferably 0.425 g / mL or more. The packing density of the carbonaceous material is, for example, 0.550 g / mL or less, preferably 0.500 g / mL or less, and more preferably 0.480 g / mL or less. That is, the packing density of the carbonaceous material is, for example, 0.350 g / mL or more and 0.550 g / mL or less, preferably 0.400 g / mL or more and 0.500 g / mL or less, and more preferably 0.425 g / mL or more and 0.480 g / mL or less.

[0069] If the packing density of the carbonaceous material is within the above range, even more excellent durability can be obtained. That is, when the carbonaceous material is used in a liquid (such as treated water), if the packing density of the carbonaceous material is within the range, the carbonaceous material can be prevented from leaking out. Furthermore, if the packing density of the carbonaceous material is within the range, excellent mechanical strength can be obtained even in a liquid. Therefore, if the packing density of the carbonaceous material is within the above range, even more excellent durability can be obtained.

[0070] The packing density can be determined in accordance with the examples described below and JIS K 1474 (2014).

[0071] (4) Adsorption performance [Reactive Black Pentavalent] The carbonaceous material preferably has a Reactive Black 5 valence within a predetermined range. The Reactive Black 5 valence is an indicator of adsorption performance.

[0072] More specifically, Reactive Black Pentavalent (g / L) is the amount of carbonaceous material required to remove 99% of Reactive Black 5 (also known as CI Reactive Black-5) contained in 1 L of test liquid (described below). Reactive Black 5 is expressed by the following formula (1):

[0073] [ka]

[0074] As shown in the above formula (1), Reactive Black 5 has a relatively high molecular weight (molecular weight 995.88) and a relatively bulky structure. Therefore, Reactive Black 5 is used as an indicator of the adsorption properties of, for example, PFOS (described later).

[0075] The pentavalent Reactive Black of the carbonaceous material is, for example, 2.0 g / L or more, preferably 3.0 g / L or more, and more preferably 4.0 g / L or more. The pentavalent Reactive Black of the carbonaceous material is, for example, 15.0 g / L or less, preferably 10.0 g / L or less, and more preferably 8.0 g / L or less. That is, the pentavalent Reactive Black of the carbonaceous material is, for example, 2.0 g / L or more and 15.0 g / L or less, preferably 3.0 g / L or more and 10.0 g / L or less, and more preferably 4.0 g / L or more and 8.0 g / L or less.

[0076] When the pentavalence of Reactive Black of the carbonaceous material is equal to or greater than the above lower limit, the carbonaceous material has pores of a size suitable for adsorbing PFOS (described below). When the pentavalence of Reactive Black of the carbonaceous material is equal to or less than the above upper limit, the carbonaceous material has a pore volume suitable for adsorbing PFOS (described below). Therefore, when the pentavalence of Reactive Black of the carbonaceous material is within the above range, even better PFOS adsorption performance can be achieved.

[0077] The Reactive Black 5 valence is measured by a known method using Reactive Black 5.

[0078] More specifically, in measuring the valence of Reactive Black 5, a test liquid (pre-adsorption sample) containing Reactive Black 5 is first prepared. Next, a carbonaceous material is mixed into the test liquid to allow the Reactive Black 5 to be sufficiently adsorbed onto the carbonaceous material. Thereafter, the carbonaceous material and the Reactive Black 5 adsorbed onto the carbonaceous material are removed to obtain a residual liquid (post-adsorption sample). Preferably, the carbonaceous material has a particle size of 50% of the cumulative volume distribution (D 50 ) is 9.0 μm or more and 11.0 μm or less.

[0079] In this method, the absorbance of the test liquid (pre-adsorption sample) and the absorbance of the residual liquid (post-adsorption sample) are measured. The absorbance is measured using a UV-visible spectrophotometer at a wavelength of 594 nm and an optical path length (cell length) of 10 mm. The residual rate (%) of Reactive Black 5 in the residual liquid (post-adsorption sample) is then calculated from the measured absorbance, and the amount of Reactive Black 5 adsorbed per gram of carbonaceous material ( / g) can also be calculated. These values ​​can then be used to calculate the Reactive Black 5 valence.

[0080] More specifically, the pentavalent value of Reactive Black can be determined in accordance with the examples described below.

[0081] [2-MIB titer] The carbonaceous material preferably has a 2-MIB value within a predetermined range. The 2-MIB value is an indicator of adsorption performance.

[0082] More specifically, 2-methylisoborneol has a relatively low molecular weight (168.28) but a relatively bulky structure. This 2-methylisoborneol is adsorbed in relatively large pores among micropores and relatively small pores among mesopores. Therefore, 2-methylisoborneol is used as an indicator of the adsorption properties of, among others, PFOA (discussed below).

[0083] The 2-MIB value of the carbonaceous material is, for example, 1.0 or more, preferably 1.5 or more, and more preferably 1.6 or more. The 2-MIB value of the carbonaceous material is, for example, 3.0 or less, preferably 2.0 or less, and more preferably 1.8 or less. That is, the 2-MIB value of the carbonaceous material is, for example, 1.0 or more and 3.0 or less, preferably 1.5 or more and 2.0 or less, and more preferably 1.6 or more and 1.8 or less.

[0084] When the 2-MIB value of the carbonaceous material is equal to or greater than the lower limit, the pore size of the carbonaceous material is particularly suitable for adsorbing PFOA (described later). Also, when the 2-MIB value of the carbonaceous material is equal to or less than the upper limit, the pore volume of the carbonaceous material is particularly suitable for adsorbing PFOA (described later). Therefore, when the 2-MIB value of the carbonaceous material is within the above range, even better PFOA adsorption performance can be obtained.

[0085] The 2-MIB value is measured using 2-methylisoborneol (abbreviated as 2-MIB) by a known method. More specifically, the 2-MIB value is measured in accordance with the Examples described below and JWWA K 113 (2005).

[0086] [Iodine adsorption amount] The carbonaceous material preferably has an iodine adsorption capacity within a predetermined range, which is an indicator of the surface area of ​​pores for adsorbing PFOS (described below) and PFOA (described below).

[0087] The iodine adsorption capacity of the carbonaceous material is, for example, 950 mg / g or more, preferably 1,050 mg / g or more. The iodine adsorption capacity of the carbonaceous material is, for example, 1,600 mg / g or less. That is, the iodine adsorption capacity of the carbonaceous material is, for example, 950 mg / g or more and 1,600 mg / g or less, preferably 1,050 mg / g or more and 1,600 mg / g or less.

[0088] If the iodine adsorption capacity of the carbonaceous material is equal to or greater than the lower limit, the surface area of ​​the pores capable of adsorbing PFOS (described later) and PFOA (described later) is relatively large, thereby achieving even better PFOA adsorption performance and even better PFOS adsorption performance. Furthermore, if the iodine adsorption capacity of the carbonaceous material is equal to or less than the upper limit, even better strength can be achieved.

[0089] The iodine adsorption amount can be determined in accordance with the examples described below and JIS K 1474 (2014).

[0090] 2.Method for producing carbonaceous materials The method for producing the carbonaceous material is not particularly limited, and examples of the method for producing the carbonaceous material include a pyrolysis method, an activation method, a coating method, and a vapor deposition method.

[0091] From the viewpoint of adjusting the specific surface area and pore volume, and from the viewpoint of adjusting the pore volume ratio, an activation method is preferable. Hereinafter, a method for producing the above carbonaceous material by the activation method will be described in detail.

[0092] (1) Preparation process In this method, first, raw material components for obtaining a carbonaceous material are prepared (preparation step).

[0093] The raw material components are not particularly limited as long as they can be carbonized (described later) and activated (described later) to obtain the carbonaceous material. For example, the raw material components include known raw material compounds.

[0094] The raw material compound is a carbonizable compound (uncarbonized). Examples of the raw material compound include natural compounds and synthetic compounds. Examples of natural compounds include wood, wood flour, fruit shells (e.g., coconut shells), seeds (palm kernels, plum seeds, and peach seeds), pulp manufacturing by-products, bagasse, molasses, coal (peat, lignite, brown coal, subbituminous coal, and bituminous coal), anthracite, petroleum distillation residue components, petroleum pitch, coke, and coal tar. Examples of synthetic compounds include synthetic resins, synthetic rubber, synthetic wood, and synthetic pulp. Examples of synthetic resins include phenolic resins, vinyl chloride resins, vinyl acetate resins, melamine resins, urea resins, resorcinol resins, celluloid, epoxy resins, polyurethane resins, polyester resins, acrylic resins, and polyamide resins. Examples of synthetic rubbers include polybutylene, polybutadiene, and polychloroprene. These can be used alone or in combination.

[0095] From the viewpoint of adjusting the specific surface area and pore volume, and from the viewpoint of adjusting the pore volume ratio, the raw material compound is preferably a natural compound, more preferably wood, wood flour, fruit shells, and coal, even more preferably coconut shells and coal, and particularly preferably coconut shells, subbituminous coal, and bituminous coal.

[0096] The raw material components may contain additives as needed. That is, the raw material components may contain raw material compounds and additives. Examples of additives include water, coal tar, anhydrous tar, hard pitch, coal tar-based pitch, petroleum-based pitch, thickening polysaccharides, and water-soluble polymers. The additives may be used alone or in combination of two or more types.

[0097] The method for mixing the raw material compound and the additive is not particularly limited. For example, the raw material compound and the additive can be heated at an appropriate heating temperature (e.g., 150°C or higher and 300°C or lower) and mixed while adjusting the oxygen concentration. The content ratio of the additive is not particularly limited and is appropriately set depending on the purpose and application. For example, the content ratio (total amount) of the additive is, for example, 1 part by mass or higher and 100 parts by mass or lower relative to 100 parts by mass of the total amount of the raw material compound and the additive.

[0098] Furthermore, the raw material components may be pulverized as necessary. The pulverization method is not particularly limited. For example, the raw material components are pulverized using a known pulverizer.

[0099] The raw material components may be molded as needed. The molding method is not particularly limited. For example, the raw material components are molded using a known molding machine.

[0100] The shape of the raw material component is not particularly limited, and examples thereof include particles, lumps, rods, pellets, substrates, sheets, and blocks, with particles being preferred. Examples of particles include powder, spheres, and crushed chips. When the raw material component is in a particulate form, the 50% particle diameter (D) of the cumulative volume distribution is used. 50) is, for example, 1 μm or more and 150 μm or less.

[0101] (2) Carbonization process Next, in this method, the raw material components are carbonized to obtain a carbonized product (carbonization step).

[0102] The carbonization method is not particularly limited, and known methods can be used, including, for example, pyrolysis carbonization, chemical decomposition carbonization, automatic low-temperature carbonization, and superheated steam carbonization.

[0103] From the viewpoint of adjusting the specific surface area and pore volume, and from the viewpoint of adjusting the pore volume ratio, the carbonization method is preferably pyrolysis carbonization, in which, for example, a raw material compound is heat-treated by a known method.

[0104] More specifically, this step uses, for example, known equipment, such as a rotary kiln, a single-stage carbonizer, and a circular agitator carbonizer.

[0105] From the viewpoint of adjusting the specific surface area and pore volume of the carbonaceous material and adjusting the pore volume ratio, a rotary kiln is preferred.

[0106] The use of a rotary kiln allows the raw material compounds to be fluidized and heat-treated, improving the uniformity of the charcoal. This allows the specific surface area, pore volume, and pore volume ratio of the carbonaceous material to be efficiently adjusted, resulting in excellent adsorption performance.

[0107] The rotary kiln will be described with reference to Figures 1 and 2. The rotary kiln 1 has a known configuration, and specifically includes a tubular body 2 and an agitating blade 3.

[0108] The tube 2 is a cylindrical member extending in the longitudinal direction and arranged rotatably in the circumferential direction. The material of the tube 2 is not particularly limited, and examples thereof include stainless steel. The inner radius L1 of the tube 2 (i.e., 1 / 2 of the inner diameter (same hereinafter)) is not particularly limited and is set depending on the purpose and use. The thickness T1 of the tube 2 is also not particularly limited and is set appropriately depending on the purpose and use.

[0109] The agitating blades 3 have a plate shape extending along the longitudinal direction. The number of agitating blades 3 is adjusted appropriately depending on the purpose and application. The number of agitating blades 3 is, for example, 1 to 20, preferably 3 to 12, more preferably 5 to 10, and particularly preferably 6. Figures 1 and 2 show six agitating blades 3, which are distinguished as agitating blades 3A to 3F.

[0110] The stirring blades 3 are arranged on the inner peripheral surface of the tubular body 2 along the longitudinal direction of the tubular body 2. More specifically, each stirring blade 3 is arranged so as to protrude from the inner wall surface of the tubular body 2 to the inside of the tubular body 2 (hollow side).

[0111] The agitating blades 3 are arranged at equal intervals in the circumferential direction of the tubular body 2. For example, when the number of agitating blades 3 is six, the agitating blades 3 are arranged at intervals of one blade per 60° in the circumferential direction of the tubular body 2.

[0112] The length L2 of the agitating blade 3 (i.e., the length along the protruding direction of the agitating blade 3) is not particularly limited and is adjusted from the viewpoint of the agitation efficiency of the raw material components 5. The length L2 of the agitating blade 3 is, for example, 10% to 30% of the inner radius L1 of the tubular body 2. The length L2 of the agitating blade 3 is also adjusted, for example, according to the amount of the raw material components 5 (see FIG. 2). For example, the length L2 of the agitating blade 3 is adjusted so that a portion of the agitating blade 3 at the bottom of the tubular body 2 (preferably ½ to ⅔ of the length L2 of the agitating blade 3) is covered with the raw material components 5.

[0113] The thickness T2 of the stirring blade 3 (length along the circumferential direction of the tubular body 2) is, for example, 1% or more and 100% or less, preferably 20% or more and 90% or less, and more preferably 30% or more and 95% or less of the thickness T1 of the tubular body 2.

[0114] The agitating blade 3 has, for example, a predetermined angle α with respect to a perpendicular line (broken line in FIG. 2) extending from the inner wall of the tubular body 2 toward the central axis of the tubular body 2. From the viewpoint of agitation efficiency, the angle α of the agitating blade 3 is, for example, 15° or more and 45° or less.

[0115] The method of heat treatment using a rotary kiln is not particularly limited, but for example, as shown in the left diagram of Fig. 2, raw material ingredients 5 are charged into a tubular body 2. Then, as shown by arrow R in the left and right diagrams of Fig. 2, the tubular body 2 is rotated in the circumferential direction, and the raw material ingredients 5 are heat-treated while being stirred by stirring blades 3, thereby carbonizing the raw material compounds. The rotation speed of the tubular body 2 is, for example, 1.0 rpm or more and 5.0 rpm or less.

[0116] The heat treatment conditions are appropriately set from the viewpoint of adjusting the specific surface area and pore volume of the carbonaceous material, and from the viewpoint of adjusting the pore volume ratio.

[0117] For example, the raw material components are heat-treated in an oxygen-free atmosphere. The oxygen-free atmosphere may be, for example, a reduced pressure atmosphere from which air is removed, or an inert gas atmosphere from which an inert gas (e.g., nitrogen) is introduced. An inert gas atmosphere is preferred, and a nitrogen atmosphere is more preferred.

[0118] The heat treatment temperature is, for example, 150°C or higher and 800°C or lower, preferably 200°C or higher and 800°C or lower, and more preferably 300°C or higher and 800°C or lower.

[0119] The heat treatment temperature may be, for example, constant, or may be increased continuously or stepwise during the heat treatment.

[0120] From the viewpoint of adjusting the specific surface area and pore volume, and from the viewpoint of adjusting the pore volume ratio, the temperature is increased continuously or stepwise.

[0121] When the heat treatment temperature is increased during the heat treatment, the heat treatment temperature at the start of the heat treatment (for example, the inlet temperature of the rotary kiln) is, for example, 150°C or more and 400°C or less, preferably 200°C or more and 350°C or less.

[0122] When the heat treatment temperature is increased during the heat treatment, the maximum temperature reached in the heat treatment (for example, the outlet temperature of a rotary kiln) is, for example, 400°C or more and 700°C or less, preferably 500°C or more and 600°C or less.

[0123] When the heat treatment temperature is increased during the heat treatment, the temperature increase rate is, for example, 2° C. / min or more and 15° C. / min or less, preferably 5° C. / min or more and 10° C. / min or less.

[0124] By increasing the heat treatment temperature during the heat treatment, the specific surface area, pore volume, and pore volume ratio of the carbonaceous material can be adjusted particularly effectively. More specifically, when a raw material compound (a carbonizable uncarbonized material) is heat-treated, the organic matter contained in the raw material compound vaporizes, forming voids. If the heat treatment temperature is increased in stages, the vaporization proceeds gradually, causing the formed voids to shrink and increasing the density. Furthermore, during the heat treatment step, some of the organic matter remains unvaporized and vaporizes in the activation step described below, creating voids. This promotes activation and the development of mesopores. In particular, if the heat treatment starting temperature is equal to or lower than the above upper limit, the organic matter can be prevented from vaporizing all at once, allowing the voids to shrink more efficiently and promoting the development of mesopores.

[0125] The heat treatment time is, for example, 30 minutes or more and 300 minutes or less, preferably 60 minutes or more and 150 minutes or less.

[0126] As described above, by heat treating the raw material components, the raw material compounds can be carbonized, and as a result, a carbide can be obtained.

[0127] In this method, the above-mentioned additives can be added to the carbide as needed. The amount of the additive added is not particularly limited and can be appropriately determined depending on the purpose and application.

[0128] The carbide (and additives (hereinafter the same)) may be pulverized as necessary. The pulverization method is not particularly limited. For example, a known pulverizer is used to pulverize the raw material components.

[0129] The carbide may be molded as needed. The molding method is not particularly limited. For example, a known molding machine is used to mold the carbide.

[0130] The carbonized material may be washed as needed. The washing method and conditions are not particularly limited and are appropriately determined depending on the purpose and application.

[0131] The carbonized material may be dried as needed. The drying method and conditions are not particularly limited and are appropriately determined depending on the purpose and application.

[0132] (3) Activation process Next, in this method, the carbonized material is subjected to an activation treatment to obtain an activated material (activation step).

[0133] The activation method is not particularly limited, and known methods can be used. For example, an activation method can be used to activate the carbonized material using an activated gas. Examples of the activated gas include water vapor, oxygen, and carbon dioxide, and preferably water vapor. An inert gas (e.g., nitrogen) can also be supplied together with the activated gas.

[0134] More specifically, in this step, for example, known equipment is used. Examples of the equipment include a rotary kiln, a fluidized bed furnace, and a sleeve furnace (vertical furnace). From the viewpoint of adjusting the specific surface area and pore volume of the carbonaceous material and adjusting the pore volume ratio, a rotary kiln is preferably used, and more preferably, a rotary kiln similar to the rotary kiln used in the carbonization step (see FIGS. 1 and 2).

[0135] The use of a rotary kiln can prevent the activated material, which has been lightened by the activation treatment, from scattering outside the furnace, thereby improving activation efficiency. Furthermore, the use of a rotary kiln can efficiently bring the carbide into contact with the activated gas. Therefore, the use of a rotary kiln can efficiently adjust the specific surface area, pore volume, and pore volume ratio of the carbonaceous material, resulting in excellent adsorption performance.

[0136] The method of activation treatment using a rotary kiln is not particularly limited, but for example, the carbide is charged into the tube 2, and while rotating the tube 2 in the circumferential direction, an activated gas is supplied to the tube 2 to activate the carbide. The rotation speed of the tube 2 is, for example, 1.0 rpm or more and 5.0 rpm or less.

[0137] The activation conditions are appropriately set from the viewpoint of adjusting the specific surface area and pore volume of the carbonaceous material and from the viewpoint of adjusting the pore volume ratio.

[0138] For example, the carbide is activated in the above-described oxygen-free atmosphere, preferably an inert gas atmosphere, more preferably a nitrogen atmosphere.

[0139] The supply rate of the active gas is set appropriately depending on the type of active gas. For example, when the active gas is water vapor, the supply rate of the active gas is 10 L / min or more and 300 L / min or less.

[0140] The activation treatment temperature is, for example, 750° C. to 1,200° C., preferably 800° C. to 1,100° C. The activation time is, for example, 20 minutes to 48 hours, preferably 30 minutes to 36 hours, more preferably 40 minutes to 24 hours, even more preferably 45 minutes to 120 minutes, and particularly preferably 50 minutes to 100 minutes.

[0141] As described above, an activated material can be obtained by subjecting a carbonized material to activation treatment.

[0142] In this method, the above-mentioned additives can be added to the activated material as needed. The amount of the additives added is not particularly limited and can be appropriately determined depending on the purpose and application.

[0143] The activator (and additive (hereinafter the same)) may be pulverized as necessary. The pulverization method is not particularly limited. For example, a known pulverizer is used to pulverize the raw material components.

[0144] The activated material may be molded as necessary. The molding method is not particularly limited. For example, the activated material is molded using a known molding machine.

[0145] (4) Cleaning process Next, in this method, the activated product is preferably washed (washing step).

[0146] An example of a method for washing the activated material is acid washing. In acid washing, the activated material is washed with a known acid. Examples of acids include inorganic acids and organic acids. Examples of inorganic acids include hydrochloric acid and nitric acid. Examples of organic acids include formic acid and acetic acid. These acids can be used alone or in combination of two or more. In acid washing, the washing temperature and washing time are not particularly limited and can be set appropriately depending on the purpose and application.

[0147] After washing the activated product with the acid, the activated product is preferably washed with water to remove the acid. The washing temperature and washing time are not particularly limited and are set appropriately depending on the purpose and application.

[0148] (5) Drying process Next, in this method, preferably, the activated product (preferably the washed activated product) is dried (drying step).

[0149] Examples of methods for drying the activated material include natural drying, heat drying, and reduced-pressure drying. From the viewpoint of adjusting the specific surface area and pore volume of the carbonaceous material and adjusting the pore volume ratio, preferred drying methods include heat drying and reduced-pressure drying, and more preferred drying methods include heat drying.

[0150] For heat drying, a known heating device is used. Examples of the heating device include a constant temperature dryer, a hot air dryer, a vacuum dryer, a rotary evaporator, a conical dryer, and a Nauta dryer. The drying temperature for heat drying is, for example, 40°C or higher and 300°C or lower.

[0151] For the reduced pressure drying, a known decompression device is used. Examples of the decompression device include an oil pump, an oilless pump, and an aspirator. The drying pressure for the reduced pressure drying is, for example, 0.00001 MPa or more and 0.05 MPa or less.

[0152] The drying time is not particularly limited, but is, for example, 1 minute to 20 hours. Preferably, drying is continued until the moisture content of the dried activated material reaches a predetermined value or less. At the end of drying, the moisture content of the dried activated material is, for example, 20% by mass or less, preferably 10% by mass or less.

[0153] As described above, the raw material components are subjected to heat treatment and activation treatment, and if necessary, washed and / or dried to produce a carbonaceous material.

[0154] The carbonaceous material obtained by the above method has, for example, the above specific surface area and the above pore volume, and / or the above pore volume ratio.

[0155] Although not described in detail, the carbonaceous material may be sized by a known method, highly purified by a known method, or imparted with durability and structure by a known method.

[0156] 3.Applications (1) PFAS-treated materials The use of the carbonaceous material is not particularly limited. Examples of uses of the carbonaceous material include a PFAS treatment material for treating organic fluorine compounds (perfluoroalkyl compounds and polyfluoroalkyl compounds (PFAS)).

[0157] Examples of PFAS include perfluoroalkanoic acid (PFAA), perfluoroalkanesulfonic acid (PFSA), perfluoroalkanesulfonamide (FASA), perfluoroalkanesulfonamideethanol (FASE), perfluoroalkanesulfonamideacetic acid (FASAA), N-methylperfluoroalkanesulfonamide (MeFASA), N-methylperfluoroalkanesulfonamideacetic acid (MeFASAA), N-methylperfluoroalkanesulfonamideethanol (MeFASE), N-ethylperfluoroalkanesulfonamide (EtFASA), N-ethylperfluoroalkane Examples of the perfluoroalkanesulfonamidoethanol include sulfonamidoethanol (EtFASE), N-ethylperfluoroalkanesulfonamidoacetic acid (EtFASAA), N-butylperfluoroalkanesulfonamide (BuFASA), N-butylperfluoroalkanesulfonamidoethanol (BuFASE), N-butylperfluoroalkanesulfonamidoacetic acid (BuFASAA), perfluoroalkanesulfonyl fluoride (PASF), fluoroprotein (FP), fluorotelomer carboxylic acid (FTCA), fluorotelomer alcohol (FTOH), fluorotelomer sulfonic acid (FTSA), derivatives thereof, and salts thereof. These may be used alone or in combination of two or more.

[0158] Specific examples of PFAS include, but are not limited to, perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluoropentanesulfonic acid (PFPeS), perfluorohexanoic acid (PFHxA), perfluorohexanesulfonic acid (PFHxS), perfluoroheptanoic acid (PFHpA), perfluoroheptanesulfonic acid (PFHpS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluoro Ammonium perfluorooctanoate (APFO), Perfluorooctanesulfonamide (PFOSA), Perfluorooctanesulfonamidoacetic acid (FOSAA), Perfluorooctanesulfonamidoethanol (FOSE), Perfluorononanoic acid (PFNA), Perfluorononanesulfonic acid (PFNS), Perfluorodecanoic acid (PFDA), Perfluorodecanesulfonic acid (PFDS), Perfluorododecanoic acid (PFDoA), Perfluorododecanesulfonic acid (PFDoSA), Perfluoroundecanoic acid (PF Perfluoroundecanesulfonic acid (PFUnSA), perfluorotridecanoic acid (PFTrDA), perfluorotetradecanoic acid (PFTeDA), N-methylperfluorooctanesulfonamide (MeFOSA), N-ethylperfluorooctanesulfonamide (EtFOSA), N-ethylperfluorooctanesulfonamidoethanol (EtFOSE), perfluorobutyric acid, perfluorophosphonic acid (PFPA), perfluorophosphinic acid (PFpiA), 4,8-dioxa-3H-perfluorooctanesulfonamide ... Examples of suitable fluorocarbons include fluorononanoic acid, 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate, ammonium 2,3,3,3-tetrafluoroethyl-2-(heptafluoropropoxy)propanoate, 1,2,2,2-tetrafluoroethyl ether, polytetrafluoroethylene (PTFE), 4:2-fluorotelomer sulfonic acid (4:2FtS), 6:2-fluorotelomer sulfonic acid (6:2FtS), 8:2-fluorotelomer sulfonic acid (8:2FtS), and salts thereof, which may be used alone or in combination.

[0159] PFAS preferably includes perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

[0160] The treatment includes, for example, removal, concentration, dilution, separation, and recovery, and preferably includes removal.

[0161] More specifically, the PFAS treatment material includes a PFAS removal material that removes PFAS (preferably PFOA and PFOS (the same applies hereinafter)).

[0162] [PFAS removal material] The PFAS-removing material is a material that removes PFAS. The PFAS-removing material contains the above-described carbonaceous material, and preferably consists of the above-described carbonaceous material.

[0163] There are no particular limitations on the method of using the PFAS removal material (i.e., the method of removing PFAS using a carbonaceous material). For example, the carbonaceous material contained in the PFAS removal material can be brought into contact with PFAS in the gas or liquid phase, allowing the PFAS to be adsorbed into the pores of the carbonaceous material, thereby removing the PFAS.

[0164] More specifically, PFAS removal materials include PFAS adsorbents.

[0165] [PFAS adsorbent] The PFAS adsorbent is a material that adsorbs PFAS. The PFAS adsorbent contains the above-mentioned carbonaceous material, and preferably consists of the above-mentioned carbonaceous material.

[0166] There are no particular limitations on the method of use of the PFAS adsorbent (i.e., the method of adsorbing PFAS using a carbonaceous material). For example, as with the PFAS removal material, the carbonaceous material contained in the PFAS adsorbent can be brought into contact with PFAS in the gas or liquid phase, allowing the PFAS to be adsorbed into the pores of the carbonaceous material, thereby removing PFAS.

[0167] (2) Specific examples The carbonaceous materials, PFAS treatment materials, PFAS removal materials, and PFAS adsorption materials can be suitably used for any application in various industrial fields.

[0168] In particular, carbonaceous materials, PFAS treatment materials, PFAS removal materials, and PFAS adsorbents are suitable for use in removing (adsorbing) PFAS in water.

[0169] That is, when carbonaceous materials are typically used in water purification facilities to remove (adsorb) PFAS from water, they are subjected to friction in the water due to water flow and pressure, and carbonaceous materials are repeatedly collided with each other. As a result, the carbonaceous materials may be pulverized in the water, and the pulverized carbonaceous materials may clog filters and increase the number of work steps in the water purification facility. Furthermore, the pulverized carbonaceous materials may increase the turbidity of the water. Therefore, in order to efficiently and continuously remove (adsorb) PFAS from water, suppress an increase in the number of work steps in the water purification facility and an increase in water turbidity, and achieve excellent environmental friendliness, carbonaceous materials used in water are particularly required to be durable. In contrast, the above-mentioned carbonaceous materials have excellent durability and are therefore suitable for use in removing (adsorbing) PFAS from water.

[0170] More specific examples of applications of the carbonaceous materials, PFAS treatment materials, PFAS removal materials, and PFAS adsorbents include adsorption filters, water purifier cartridges, water purifiers, packed towers, household drinking water treatment, and water purification equipment, and preferably include adsorption filters, water purifier cartridges, water purifiers, and water purification equipment.

[0171] [Adsorption filter] The adsorption filter contains the carbonaceous material described above, and more specifically, comprises the PFAS adsorbent described above.

[0172] The specific configuration of the adsorption filter is not particularly limited. For example, the adsorption filter contains the above-mentioned carbonaceous material and a fibrous binder for holding the carbonaceous material.

[0173] The fibrous binder is not particularly limited as long as it can hold the carbonaceous material, and examples thereof include known fibrous binders. Examples of fibrous binders include acrylic fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, cellulose fibers, nylon fibers, aramid fibers, and pulp. These can be used alone or in combination of two or more. From the viewpoint of improving the density and strength of the adsorption filter, polyacrylonitrile fibers and pulp are preferred.

[0174] The adsorption filter may contain other functional components. Examples of the other functional components include adsorbents other than carbonaceous materials. Examples of adsorbents other than carbonaceous materials include titanosilicate, zeolite, silica gel, activated alumina, nonwoven fabric, ion exchange resin, chelating resin, porous organic compound, silver ion, and silver compound.

[0175] The method for obtaining the adsorption filter is not particularly limited. For example, an adsorption filter can be obtained by holding a carbonaceous material (and other functional components (the same applies hereinafter)) on a fibrous binder using a known method. The content ratio of the carbonaceous material to the fibrous binder is set from the viewpoint of PFAS removal performance. For example, the amount of the fibrous binder relative to 100 parts by mass of the carbonaceous material is, for example, 0.01 parts by mass or more and 20 parts by mass or less, preferably 0.01 parts by mass or more and 10 parts by mass or less.

[0176] The method for using the adsorption filter is not particularly limited. For example, the adsorption filter is used as an adsorption filter for a water purifier. Specifically, water passes through the adsorption filter and is purified. The water passing speed is appropriately set depending on the purification efficiency and pressure loss.

[0177] The adsorption filter contains the carbonaceous material. Therefore, the adsorption filter has excellent durability and excellent PFAS removal performance. Such an adsorption filter is suitable for use as an adsorption filter for water purifiers to remove (adsorb) PFAS in water.

[0178] [Water purifier cartridge] The water purification cartridge contains the carbonaceous material described above, and more specifically, comprises the PFAS adsorbent described above.

[0179] The specific configuration of the water purifier cartridge is not particularly limited. For example, the water purifier cartridge includes a housing for removing (adsorbing) PFAS. The housing includes, for example, the carbonaceous material and / or the adsorption filter, and is designed to remove (adsorb) PFAS in water.

[0180] The water purifier cartridge may also include other components as needed. Examples of such other components include adsorbents other than carbonaceous materials, nonwoven fabric filters, mineral additives, ceramic filter materials, and hollow fiber membranes. These may be used alone or in combination of two or more. The method for obtaining the water purifier cartridge is not particularly limited. For example, a water purifier cartridge having a known configuration may be manufactured by a known method.

[0181] The water purifier cartridge contains the carbonaceous material, and therefore has excellent durability and excellent PFAS removal performance.

[0182] [Water purifier] The water purifier contains the carbonaceous material described above, and more specifically, includes the PFAS adsorbent described above.

[0183] The specific configuration of the water purifier is not particularly limited. For example, the water purifier includes a water purifier cartridge (preferably the water purifier cartridge described above).

[0184] The water purifier cartridge includes, for example, a housing for removing (adsorbing) PFAS. The housing includes, for example, the carbonaceous material and / or the adsorption filter, and is designed to remove (adsorb) PFAS in water.

[0185] The water purifier may further include other components as necessary. The method for producing the water purifier is not particularly limited. For example, a water purifier having a known configuration may be produced by a known method.

[0186] The water purifier contains the carbonaceous material, and therefore has excellent durability and excellent PFAS removal performance.

[0187] Therefore, the water purifier is suitable for use as a water purifier for a water faucet device and a water purifier for a kitchen, for example.

[0188] [Water purification equipment] The water purification system contains the carbonaceous material described above, and more specifically, includes the PFAS adsorbent described above.

[0189] Examples of water purification equipment include water purification equipment, wastewater treatment equipment, and water purification equipment. Examples of water purification equipment include pure water production equipment, ultrapure water equipment, and water purification plants. Examples of wastewater treatment equipment include industrial wastewater treatment equipment and industrial wastewater treatment equipment. Examples of water purification equipment include pharmaceutical water purification equipment and food water purification equipment. The method for obtaining water purification equipment is not particularly limited. For example, water purification equipment having a known configuration is manufactured using a known method.

[0190] The water purification equipment contains the carbonaceous material, and therefore the water purifier has excellent durability and excellent PFAS removal performance.

[0191] [Other uses] The uses are not limited to the above. For example, the carbonaceous material and the PFAS treatment agent can be suitably used in various treatment devices for treating PFAS by treatment methods other than adsorption (e.g., removal, concentration, dilution, separation, and recovery).

[0192] Examples of the treatment device include devices equipped with various filters (for example, columns, tanks, tubes, bathtubs, cylinders, sheets, and films), such as known filtration devices, known adsorption devices, and known concentration devices. More specific examples of the treatment device include household drinking water treatment devices, water treatment devices for industrial processes, purification devices for industrial processes, and wastewater treatment devices for industrial processes. [Example]

[0193] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Form for Carrying Out the Invention."

[0194] 1.Carbonaceous material [Example 1] (preparation process) Coconut shells were prepared as a carbon source.

[0195] (carbonization process) The raw material components were heat-treated in a nitrogen atmosphere using a rotary kiln equipped with stirring blades (see FIGS. 1 and 2) to obtain a carbide.

[0196] Rotary kiln design Number of stirring blades: 6 (1 every 60° around the circumference of the pipe) Agitator blade angle: 15° to 45° Length of stirring blade: 15% to 25% of the inner radius of the tube Thickness of stirring blade: 40% to 80% of the thickness of the tube

[0197] Heat treatment conditions Initial temperature: 150℃ Heating rate: 5℃ / min Heat treatment time: 90 minutes Rotation speed: 3.0 rpm

[0198] (Activation process) The carbide was charged into the rotary kiln, and while rotating the rotary kiln, steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0199] Activation conditions Activation temperature: 900℃ Activation time: 390 minutes Rotation speed: 3.0 rpm

[0200] (Cleaning process) The activated product was washed with dilute hydrochloric acid and then with water to remove the hydrochloric acid.

[0201] (drying process) The washed activated material was dried to obtain a dried material, which was then pulverized to obtain a carbonaceous material.

[0202] [Example 2] A carbonaceous material was obtained in the same manner as in Example 1, except that the activation time in the activation step was changed to 200 minutes.

[0203] [Example 3] (preparation process) Bituminous coal was pulverized to obtain coal powder. The coal powder and water were kneaded to obtain a kneaded mixture. The kneaded mixture was compacted and molded using an extrusion molding machine to obtain a molded product. The molded product was crushed, and the crushed product was sieved and then dried to obtain a raw material component containing bituminous coal.

[0204] (carbonization process) The raw material components were heat-treated under a nitrogen atmosphere using the same rotary kiln as in Example 1 to obtain a carbide. The heat treatment conditions are as follows.

[0205] Heat treatment conditions Initial temperature: 200℃ Heating rate: 10℃ / min Heat treatment time: 50 minutes Rotation speed: 3.0 rpm

[0206] (Activation process) The carbide was charged into the rotary kiln, and while rotating the rotary kiln, steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0207] Activation conditions Activation temperature: 950℃ Activation time: 260 minutes Rotation speed: 3.0 rpm

[0208] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0209] [Example 4] (preparation process) Bituminous coal was pulverized to obtain coal powder. The coal powder and water were kneaded to obtain a kneaded mixture. The kneaded mixture was molded into spherical shapes using a tumbling granulator to obtain a molded product. The molded product was dried to obtain a raw material component containing bituminous coal.

[0210] (carbonization process) The raw material components were heat-treated under a nitrogen atmosphere using the same rotary kiln as in Example 1 to obtain a carbide. The heat treatment conditions are as follows.

[0211] Heat treatment conditions Initial temperature: 200℃ Heating rate: 10℃ / min Heat treatment time: 50 minutes Rotation speed: 3.0 rpm

[0212] (Activation process) The carbide was charged into the rotary kiln, and while rotating the rotary kiln, steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0213] Activation conditions Activation temperature: 900℃ Activation time: 100 minutes Rotation speed: 3.0 rpm

[0214] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0215] [Example 5] (preparation process) 50 parts by mass of subbituminous coal and 50 parts by mass of bituminous coal were mixed and crushed to obtain coal powder. The coal powder, pitch, and water were kneaded to obtain a kneaded mixture. The kneaded mixture was molded into spheres using a tumbling granulator to obtain a molded product. The molded product was dried to obtain a raw material component containing subbituminous coal and bituminous coal.

[0216] (carbonization process) The raw material components were heat-treated under a nitrogen atmosphere using the same rotary kiln as in Example 1 to obtain a carbide. The heat treatment conditions are as follows.

[0217] Heat treatment conditions Initial temperature: 200℃ Heating rate: 10℃ / min Heat treatment time: 50 minutes Rotation speed: 3.0 rpm

[0218] (Activation process) The carbide was charged into the rotary kiln, and while rotating the rotary kiln, steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0219] Activation conditions Activation temperature: 900℃ Activation time: 100 minutes Rotation speed: 3.0 rpm

[0220] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0221] [Example 6] (preparation process) Coconut shells were prepared as a raw material component.

[0222] (carbonization process) The raw material components were heat-treated under a nitrogen atmosphere using the same rotary kiln as in Example 1 to obtain a carbide. The heat treatment conditions are as follows.

[0223] Heat treatment conditions Initial temperature: 200℃ Heating rate: 5℃ / min Heat treatment time: 80 minutes Rotation speed: 3.0 rpm

[0224] (Activation process) The carbide was charged into the rotary kiln, and while rotating the rotary kiln, steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0225] Activation conditions Activation temperature: 900℃ Activation time: 400 minutes Rotation speed: 3.0 rpm

[0226] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0227] [Example 7] (preparation process) Subbituminous coal was pulverized to obtain coal powder. The coal powder was kneaded with pitch and water to obtain a kneaded mixture. The kneaded mixture was molded into spherical shapes using a tumbling granulator to obtain a molded product. The molded product was dried to obtain a raw material component containing subbituminous coal.

[0228] (carbonization process) The raw material components were heat-treated under a nitrogen atmosphere using the same rotary kiln as in Example 1 to obtain a carbide. The heat treatment conditions are as follows.

[0229] Heat treatment conditions Initial temperature: 200℃ Heating rate: 10℃ / min Heat treatment time: 50 minutes Rotation speed: 3.0 rpm

[0230] (Activation process) The carbide was charged into the rotary kiln, and while rotating the rotary kiln, steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0231] Activation conditions Activation temperature: 900℃ Activation time: 110 minutes Rotation speed: 3.0 rpm

[0232] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0233] [Comparative Example 1] (preparation process) Coconut shells were prepared as a raw material component.

[0234] (carbonization process) The raw material components were heat-treated in a nitrogen atmosphere using a known rotary kiln (not shown) without stirring blades to obtain a carbide. The heat treatment conditions are as follows:

[0235] Heat treatment conditions Initial temperature: 150℃ Heating rate: 10℃ / min Heat treatment time: 70 minutes Rotation speed: 3.0 rpm

[0236] (Activation process) The carbide was charged into a known rotary kiln (not shown) without stirring blades, and the rotary kiln was rotated while steam was introduced into the kiln to activate the carbide, obtaining an activated product. The amount of the carbide was approximately 0.06 times the volume of the rotary kiln. The activation conditions are as follows:

[0237] Activation conditions Activation temperature: 900℃ Activation time: 130 minutes Rotation speed: 3.0 rpm

[0238] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0239] Comparative Example 2 Wood flour obtained from cedar was dried to obtain dried wood flour. Next, 100 parts by mass of the dried wood flour was mixed with 300 parts by mass of an aqueous zinc chloride solution (70% by mass concentration) to obtain a mixture. The mixture was heated to 700°C in a rotary electric furnace for 1 hour to activate the dried wood flour with zinc chloride, obtaining an activated product.

[0240] (Washing process and drying process) The activated product was washed and dried in the same manner as in Example 1, and the dried product was then crushed to obtain a carbonaceous material.

[0241] Comparative Example 3 A carbonaceous material was obtained in the same manner as in Comparative Example 1, except that the heat treatment conditions in the carbonization step and the activation treatment conditions in the activation step were changed as follows.

[0242] Heat treatment conditions Initial temperature: 150℃ Heating rate: 15℃ / min Heat treatment time: 30 minutes Rotation speed: 3.0 rpm

[0243] Activation conditions Activation temperature: 900℃ Activation time: 120 minutes Rotation speed: 3.0 rpm

[0244] 2. Evaluation The carbonaceous materials were evaluated by the following methods, and the results are shown in Tables 1 to 3.

[0245] [N2 adsorption isotherms of carbonaceous materials at -196℃] Using a specific surface area / pore distribution measuring device (BELSORP (registered trademark)-mini II (product name) manufactured by Microtrack-Bell), the carbonaceous material was heated at 250°C under reduced pressure (vacuum degree: 0.1 kPa or less) for 3 hours. Thereafter, the N adsorption isotherm of the carbonaceous material at -196°C was measured.

[0246] [BET specific surface area] Specific surface area of ​​carbonaceous material (unit: m 2 / g) was determined by the BET method from the N2 adsorption isotherm at -196°C.

[0247] That is, using the above N2 adsorption isotherm, a straight line was obtained in the region of relative pressure P / P0 = 0.01 or more and 0.10 or less by BET analysis (multipoint method), and the BET specific surface area was calculated from the obtained straight line.

[0248] [Pore volume of pores with diameters of 2 to 4 nm (A)] The cumulative pore volume of pores with diameters of 2 to 4 nm contained in 1 g of the carbonaceous material (i.e., pore volume (A) of pores with diameters of 2 to 4 nm, unit: mL / g) was calculated by the CI method from the above N2 adsorption isotherm.

[0249] [Volume of pores with diameters of 1.2 nm or less (B)] The cumulative pore volume of pores with a diameter of 1.2 nm or less contained in 1 g of the carbonaceous material (i.e., pore volume (B) of pores with a diameter of 1.2 nm or less, unit: mL / g) was calculated by the CI method from the above N2 adsorption isotherm.

[0250] [Pore volume (C) of pores with diameters of 9 to 25 nm] The cumulative pore volume of pores with diameters of 9 to 25 nm contained in 1 g of the carbonaceous material (i.e., the pore volume (C) of pores with diameters of 9 to 25 nm, unit: mL / g) was calculated by the CI method from the above N2 adsorption isotherm.

[0251] [Pore volume ratio ((A) / (B))] From the above pore volume (A) and the above pore volume (B), the ratio of the volume of pores (A) with a pore diameter of 2 to 4 nm to the volume of pores (B) with a pore diameter of 1.2 nm or less (pore volume ratio (A) / (B)) was calculated.

[0252] [Pore volume ratio ((C) / (B))] From the above pore volume (B) and the above pore volume (C), the ratio of the volume of pores (C) with a pore diameter of 9 to 25 nm to the volume of pores (B) with a pore diameter of 1.2 nm or less (pore volume ratio (C) / (B)) was calculated.

[0253] [Microstrength hardness (MS hardness)] The MS hardness of the carbonaceous material was measured by the following method. First, the carbonaceous material was sieved using a sieve having a predetermined particle size range. The particle size range of the sieve was selected based on the description of "hardness" in JIS K 1474 (2014).

[0254] Next, 10 g of the sieved carbonaceous material was placed in a container (inner diameter 25 mm × 300 mm, stainless steel) shown in Figure 3. Ten steel balls with a diameter of 7.94 mm were also placed in the container. The container was then rotated at 25 revolutions per minute for 40 minutes. The contents of the container were then removed, and the carbonaceous material and the steel balls were separated.

[0255] The carbonaceous material was then sieved using a sieve having the above-mentioned predetermined particle size range, and the MS hardness was calculated according to the following formula.

[0256] MS hardness (%) = [mass of carbonaceous material on sieve] / [mass of carbonaceous material on sieve + mass of carbonaceous material under sieve] × 100 (%)

[0257] [Average particle size] The average particle size (representative diameter) of the carbonaceous material was calculated according to the method for calculating the mass average particle size in JIS K 1474 (2014).

[0258] That is, the carbonaceous material was dried for 3 hours in a constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C to obtain a dried product. Thereafter, the dried carbonaceous material was left in a desiccator equipped with silica gel as a desiccant and allowed to cool to room temperature. Next, 100 g of the carbonaceous material after cooling was taken, and its mass was measured to the nearest 0.1 g.

[0259] On the other hand, multiple sieves were stacked on a tray, with the mesh sizes decreasing from the top to the bottom.

[0260] The carbonaceous material was placed on the top sieve of the stacked sieves and covered. These were then attached to a sieve shaker (manufactured by Iida Seisakusho Co., Ltd.) and sieved for 10 minutes (beating rate: 130-165 rpm, rotation rate: 240-295 rpm). The mass of the carbonaceous material remaining on each sieve and in the receiving tray was then measured to the nearest 0.1 g. The particle size (%) of the carbonaceous material on each sieve was then calculated using the following formula:

[0261] Particle size (%) = [mass of carbonaceous material remaining on each sieve and in the receiving tray] / [total mass of carbonaceous material remaining on each sieve and in the receiving tray] × 100 (%)

[0262] Furthermore, the average particle size (mm) of the carbonaceous material was calculated using the following formula: In the formula, the total number of sieves is n, the mesh size of the sieve with the smallest mesh size is r1 (mm), and the mesh sizes of the sieves with increasing mesh sizes are r2, r3, ...rn (mm).

[0263] Average particle size (mm) = ([average of r1 + r2 (mm)] × [particle size (%) of carbonaceous material on sieve with opening r1] + [average of r2 + r3 (mm)] × [particle size (%) of carbonaceous material on sieve with opening r2] + … [average of rn-1 + rn (mm)] × [particle size (%) of carbonaceous material on sieve with opening rn-1]) / [total particle size (%) of carbonaceous material between the bottom sieve and the top sieve]

[0264] [Filling density] The packing density (g / mL) of the carbonaceous material was determined in accordance with JIS K 1474 (2014).

[0265] Specifically, the carbonaceous material was dried for 3 hours in a constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C to obtain a dried product. Thereafter, the dried carbonaceous material was left in a desiccator equipped with silica gel as a desiccant and allowed to cool to room temperature.

[0266] Next, the carbonaceous material after cooling was introduced into the storage funnel of a bulk specific gravity measuring instrument (Tsutsui Scientific Instruments Co., Ltd.). Then, the carbonaceous material was filled up to the marked line of a 100 mL measuring cylinder (Shibata Chemical Industries, Ltd. (trade name)) while adjusting the sample supply rate to 0.75 to 1.0 mL / s using the attached vibrator. The mass of the carbonaceous material after filling was then measured to the nearest 0.1 g.

[0267] Next, the packing density (g / mL) of the carbonaceous material was calculated using the following formula.

[0268] Packing density (g / mL) = mass of carbonaceous material (g) / measured sample volume (mL)

[0269] [Reactive Black Pentavalent (RB Pentavalent)] The pentavalent content of Reactive Black (g / L) was measured using the following method.

[0270] That is, the carbonaceous material is divided into particles with a particle diameter of 50% of the cumulative volume distribution (D 50 The carbonaceous material was pulverized so that the particle size was 10.0 μm or less. The pulverized carbonaceous material was then dried for 3 hours in a constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C to obtain a dried product. Thereafter, the carbonaceous material was left in a desiccator equipped with silica gel as a desiccant and allowed to cool to room temperature.

[0271] Separately, test solution A containing phosphate buffer and Reactive Black 5 (Sigma-Aldrich) was prepared by the following method. Specifically, 7.26 g of potassium dihydrogen phosphate (Fujifilm Wako Pure Chemical Industries, Ltd.) and 28.66 g of disodium hydrogen phosphate dodecahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in 2 L of distilled water to prepare phosphate buffer (pH: 7.0). Then, Reactive Black 5 was added to 1 L of phosphate buffer to prepare test solution A.

[0272] The amount of Reactive Black 5 to be added to Test Solution A was determined by the following method. Specifically, the amount of Reactive Black 5 to be added to 1 L of phosphate buffer was adjusted so that when Test Solution A was diluted 20 times with distilled water, a diluted solution (hereinafter referred to as Test Solution B) having an absorbance of 1.18 to 1.23 was obtained. The amount of Reactive Black 5 was 0.5 to 1.2 g.

[0273] Next, the carbonaceous material and 50 mL of test liquid A were placed in a 100 mL Erlenmeyer flask with a stopper and mixed to obtain a mixed liquid. Specifically, the carbonaceous material and test liquid A were shaken in a water bath at 40°C at a speed of 150 times per minute for 5 hours using a constant temperature shaking bath (manufactured by Taitec Corporation, Water Bath Shaker MM-10 (trade name)), to obtain a mixed liquid.

[0274] The amount of carbonaceous material added to test liquid A was adjusted so that the residual rate of Reactive Black 5 in the filtrate described below was about 1%.

[0275] Next, the mixed liquid was filtered using a membrane filter (DISMIC (registered trademark) 25HP045AN (product name) manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate.

[0276] Next, the absorbance of Test Solution B (i.e., a 20-fold diluted solution of Test Solution A) and the absorbance of the filtrate were each measured. The absorbance was the absorbance of light with a wavelength of 594 nm. The absorbance was measured using a glass cell with an optical path length of 10 mm with a UV-visible spectrophotometer (Hitachi High-Technologies, Double Beam Spectrophotometer U-2910 (product name)).

[0277] Next, the amount of Reactive Black 5 adsorbed per 1 g of the carbonaceous material (hereinafter referred to as "RB5 adsorption amount ( / g) per 1 g of the carbonaceous material") was calculated using the following formula.

[0278] Amount of RB5 adsorbed per 1 g of carbonaceous material ( / g) = [(absorbance of test solution B at a wavelength of 594 nm) × 20] - [absorbance of filtrate at a wavelength of 594 nm] / mass of carbonaceous material (g)

[0279] Furthermore, the residual rate of Reactive Black 5 contained in the filtrate (hereinafter referred to as "RB5 residual rate (%)") was calculated using the following formula.

[0280] RB5 residual rate (%) = [absorbance of filtrate at 594 nm] / [(absorbance of test solution B at 594 nm) × 20] × 100

[0281] Next, a power approximation curve was created using the RB5 residual rate (%) as the horizontal axis and the RB5 adsorption amount ( / g) per 1 g of carbonaceous material as the vertical axis.

[0282] Next, the adsorption amount of Reactive Black 5 when the residual rate of Reactive Black 5 was 1% (hereinafter referred to as "RB5 adsorption amount ( / g) when RB5 residual rate is 1%) was determined using the above power approximation formula.

[0283] Next, the pentavalent value of Reactive Black (g / L) was calculated using the following formula.

[0284] Reactive Black Pentavalent (g / L) = [(Absorbance of Test Solution B at 594 nm) x 20] x 0.99 / [RB5 adsorption amount ( / g) at 1% RB5 residual rate] / 0.05 (L)

[0285] In the above formula, 0.05 (L) represents the amount of test liquid.

[0286] [2-MIB titer] The 2-MIB value of carbonaceous materials was measured in accordance with JWWA K 113 (2005-2) using the following method.

[0287] That is, the carbonaceous material is divided into particles with a particle diameter of 50% of the cumulative volume distribution (D 50The carbonaceous material was then pulverized to a particle size of approximately 10.0 μm or less. The pulverized carbonaceous material was then dried for 3 hours in a constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C to obtain a dried product. Thereafter, the carbonaceous material was left in a desiccator equipped with silica gel as a desiccant and allowed to cool to room temperature.

[0288] Separately, test solution C containing methanol and 2-MIB (2-methylisoborneol) was prepared by the following method. Specifically, a 2-MIB standard solution (0.1 mg / mL methanol solution, Fujifilm Wako Pure Chemical Industries, Ltd.) was diluted with methanol (Fujifilm Wako Pure Chemical Industries, Ltd.) to prepare a 1 mg / L 2-MIB solution. The resulting 2-MIB solution was used as test solution C.

[0289] Next, test solution C was diluted with distilled water to prepare a diluted solution (hereinafter referred to as test solution D). 100 mL of test solution D was dispensed into a 200 mL Erlenmeyer flask with a ground stopper.

[0290] Meanwhile, about 0.2 g of the carbonaceous material was dispensed into a 1 L measuring flask and the volume was increased to 1 L using distilled water, thereby obtaining a suspension containing the carbonaceous material and water.

[0291] Next, the suspension and 100 mL of test solution D were placed in a 200 mL Erlenmeyer flask with a stopper, and distilled water was added to the Erlenmeyer flask so that the total volume was 200 mL. The mixture was mixed to obtain a mixed solution. More specifically, the suspension, test solution D, and water were shaken in a 25°C water bath at a speed of 150 rpm for 60 minutes using a constant temperature shaking bath (manufactured by Taitec Corporation, Water Bath Shaker MM-10 (trade name)) to obtain a mixed solution. The mixed solution was then allowed to stand for 30 minutes. The blending amounts of the suspension (i.e., carbonaceous material and water) were adjusted so that the "residual 2-MIB concentration" described below was approximately 20 ng / L.

[0292] Thereafter, the mixed liquid was filtered using a membrane filter (DISMIC (registered trademark) 25HP045AN (trade name), manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate.

[0293] Next, the 2-MIB content of the filtrate was measured by the calibration curve method using a gas chromatograph-mass spectrometer (manufactured by Shimadzu Corporation, GCMS-QP2020 (trade name)).

[0294] The calibration curve used for the measurements was prepared as follows: 1 to 50 mL of test solution C was dispensed stepwise into 100 mL measuring flasks, and these were diluted with distilled water to a total volume of 100 mL. The 2-MIB content of the diluted solution was then measured using a gas chromatograph-mass spectrometer (Shimadzu Corporation, GCMS-QP2020 (trade name)), and a calibration curve was prepared based on these results.

[0295] The 2-MIB concentration in the filtrate was defined as the "residual 2-MIB concentration," and the amount of 2-MIB adsorbed per mg of carbonaceous material was calculated using the following formula.

[0296] Amount of 2-MIB adsorbed per 1 g of carbonaceous material (ng / mg) = [2-MIB concentration in test solution D (400 ng / L)] - [residual 2-MIB concentration in filtrate] × 0.2 (L) / 0.2 (mg)

[0297] Then, according to Freundlich's adsorption isotherm, an adsorption isotherm was created using the "residual 2-MIB concentration" as the horizontal axis and the "amount of 2-MIB adsorbed per 1 mg of carbonaceous material" as the vertical axis.

[0298] Next, using the above adsorption isotherm, the amount of 2-MIB adsorbed per mg of carbonaceous material (ng / mg) when the residual 2-MIB concentration was 20 ng / L was calculated.Then, the 2-MIB titer was calculated using the following formula.

[0299] 2-MIB titer = [200 - 20] / [2-MIB adsorption amount (ng / mg) per mg of carbonaceous material when the residual 2-MIB concentration is 20 ng / L]

[0300] [Iodine adsorption amount] The iodine adsorption capacity (mg / g) of the carbonaceous material was determined in accordance with JIS K 1474 (2014).

[0301] That is, the carbonaceous material was pulverized in accordance with JIS Z 8801-1. Pulverization was continued until 90% or more of the pulverized carbonaceous material passed through a 45 μm mesh sieve. Next, the pulverized carbonaceous material was dried for 3 hours in a constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C. Thereafter, the dried carbonaceous material was left in a desiccator containing silica gel as a desiccant and allowed to cool to room temperature.

[0302] Meanwhile, 25.0 g of potassium iodide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 13.0 g of iodine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in approximately 1 L of distilled water to prepare an iodine solution.

[0303] The iodine solution was titrated with a 0.1 mol / L sodium thiosulfate solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to measure the concentration of the iodine solution. Next, distilled water was added to the iodine solution to adjust the concentration of the iodine solution. In this way, a 0.05 mol / L iodine solution was prepared.

[0304] Next, the carbonaceous material was weighed and placed in a 100 mL Erlenmeyer flask with a stopper. 50 mL of the 0.05 mol / L iodine solution was added to the Erlenmeyer flask using a volumetric pipette. The amount of carbonaceous material was adjusted so that the residual iodine concentration in the supernatant of the filtrate, described below, was approximately 2.5 g / L.

[0305] Next, the content of the Erlenmeyer flask was shaken at room temperature (20°C or higher and 30°C or lower) at 200 rpm for 15 minutes using a shaker (medium-sized shaker Reciprocating Shaker NR-10 (trade name), manufactured by Taitec Co., Ltd.) to obtain a mixed solution. In addition, iodine was adsorbed onto the carbonaceous material in the mixed solution.

[0306] Next, the mixed liquid was filtered using a cellulose mixed ester membrane filter (manufactured by Advantec Toyo Co., Ltd., A045A025A (trade name)) to obtain a filtrate.

[0307] Next, 10 mL of the supernatant of the filtrate was collected with a volumetric pipette and titrated with 0.1 mol / L sodium thiosulfate solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., factor: 1.000).

[0308] The residual iodine concentration in the supernatant of the filtrate was then calculated using the following formula.

[0309] Residual iodine concentration (g / L) = [amount of 0.1 mol / L sodium thiosulfate solution used in titration (mL)] × [factor of 0.1 mol / L sodium thiosulfate solution] × 12.69 / 10

[0310] Then, the amount of iodine adsorbed per 1 g of the carbonaceous material was calculated using the following formula.

[0311] Amount of iodine adsorbed per 1 g of carbonaceous material = (10 × [factor of 0.05 mol / L iodine solution] - [volume (mL) of 0.1 mol / L sodium thiosulfate solution used for titration] × [factor of 0.1 mol / L sodium thiosulfate solution] × 12.69 × 5 / mass (g) of carbonaceous material

[0312] The factor of the 0.05 mol / L iodine solution was calculated using the following formula.

[0313] Factor of 0.05 mol / L iodine solution = [volume (mL) of 0.1 mol / L sodium thiosulfate solution used in titration] × [factor of 0.1 mol / L sodium thiosulfate solution] / 10

[0314] Then, according to Freundlich's adsorption isotherm, an adsorption isotherm was created using the "iodine residual concentration" as the horizontal axis and the "iodine adsorption amount per 1 g of carbonaceous material" as the vertical axis.

[0315] Next, using the above adsorption isotherm, the amount of iodine adsorbed (mg / g) per 1 g of carbonaceous material when the residual iodine concentration was 2.5 g / L was calculated.

[0316] [PFOS adsorption amount] The amount of PFOS adsorbed (μg / mg) by the carbonaceous material was determined by the following method.

[0317] That is, the carbonaceous material is divided into particles with a particle diameter of 50% of the cumulative volume distribution (D 50 The carbonaceous material was then pulverized to a particle size of approximately 10.0 μm or less. The pulverized carbonaceous material was then dried for 3 hours in a constant temperature dryer (manufactured by Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C to obtain a dried product. Thereafter, the carbonaceous material was left in a desiccator equipped with silica gel as a desiccant and allowed to cool to room temperature.

[0318] Separately, test solution E containing perfluorooctanesulfonic acid (PFOS) was prepared by the following method. Specifically, commercially available perfluorooctanesulfonic acid (100 μg / mL in MeOH) (manufactured by AccuStandard) was diluted with ultrapure water to prepare a diluted solution with a PFOS concentration of 50 μg / L. The resulting diluted solution was used as test solution E.

[0319] Next, 100 mL of test solution E was dispensed into a 200 mL Erlenmeyer flask equipped with a stopper.

[0320] Furthermore, a carbonaceous material was added to the Erlenmeyer flask. The amount of the carbonaceous material added was adjusted so that the "PFOS residual concentration" described below was about 10 μg / L.

[0321] Next, the contents of the Erlenmeyer flask were shaken in a water bath at 25°C for 5 hours at a speed of 148 rpm using a thermostatic shaking bath (manufactured by Taitec Corporation, Water Bath Shaker MM-10 (trade name)), to obtain a mixed solution. Furthermore, by the above operation, PFOS was adsorbed onto the carbonaceous material.

[0322] Thereafter, the mixed liquid was filtered using a filter paper made of cellulose acetate with a pore size of 0.2 μm (DISMIC (registered trademark) 13CP020AN (product name), manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate.

[0323] The PFOS concentration in the filtrate was then quantified using a liquid chromatograph mass spectrometer (Agilent Technologies, 1200 series / 6130 quadrupole LC / MS (trade name)) under the following conditions.

[0324] Delay column: ZORBAX Eclipse Plus C18 4.6x50mm 3.5μm (Agilent Technologies) Separation column: ZORBAX RRHD Eclipse Plus C18 2.1 x 100 mm 1.8 μm (Agilent Technologies) Mobile phase: ammonium acetate solution (i.e., 10 mmol / L ammonium acetate solution prepared by diluting 1 mol / L ammonium acetate solution (Fujifilm Wako Pure Chemical Industries, Ltd.) with ultrapure water), and acetonitrile (for PFOA / PFOS analysis, Fujifilm Wako Pure Chemical Industries, Ltd.)

[0325] The PFOS concentration (measured value) in the filtrate obtained by the above measurement was defined as the "residual PFOS concentration," and the amount of PFOS adsorbed per mg of carbonaceous material was calculated using the following formula.

[0326] Amount of PFOS adsorbed per 1 mg of carbonaceous material (μg / mg) = [PFOS concentration in test liquid (50 μg / L) - residual PFOS concentration in filtrate (μg / L)] × 0.1 / [mass of carbonaceous material (mg)]

[0327] Then, according to Freundlich's adsorption isotherm, an adsorption isotherm was created using the "PFOS residual concentration" as the horizontal axis and the "PFOS adsorption amount per 1 mg of carbonaceous material" as the vertical axis.

[0328] Next, using the above adsorption isotherm, the amount of PFOS adsorbed per mg of carbonaceous material (μg / mg) when the residual PFOS concentration was 10 μg / L was calculated. The amount of PFOS adsorption was also evaluated as the PFOS adsorption performance.

[0329] [PFOA adsorption amount] The amount of PFOA adsorption (μg / mg) was measured in the same manner as for the measurement of the amount of PFOS adsorption, except that perfluorooctane sulfonic acid (100 μg / mL in MeOH) was replaced with perfluorooctanoic acid (100 μg / mL in MeOH).

[0330] The PFOA concentration (measured value) in the filtrate obtained by the above measurement was defined as the "residual PFOA concentration," and the amount of PFOA adsorbed per mg of carbonaceous material was calculated using the following formula.

[0331] Amount of PFOA adsorbed per 1 mg of carbonaceous material (μg / mg) = [PFOA concentration in test liquid (50 μg / L) - residual PFOA concentration in filtrate (μg / L)] × 0.1 / [mass of carbonaceous material (mg)]

[0332] Then, according to Freundlich's adsorption isotherm, an adsorption isotherm was created using the "PFOA residual concentration" as the horizontal axis and the "PFOA adsorption amount per 1 mg of carbonaceous material" as the vertical axis.

[0333] Next, using the above adsorption isotherm, the amount of PFOA adsorbed per mg of carbonaceous material (μg / mg) when the residual PFOA concentration was 10 μg / L was calculated. The amount of PFOA adsorption was also evaluated as the PFOA adsorption performance.

[0334] [Table 1]

[0335] [Table 2]

[0336] [Table 3] [Explanation of symbols]

[0337] 1. Rotary kiln 2. Body 3 stirring blades 5 Raw material ingredients

Claims

1. N at -196°C ２ In the pore volume obtained by the CI method from the adsorption isotherm, the ratio ((A) / (B)) of the volume of pores having a diameter of 2 to 4 nm to the volume of pores having a diameter of 1.2 nm or less is 0.085 or more and 0.410 or less; A carbonaceous material in which the ratio ((C) / (B)) of the volume of pores having a diameter of 9 to 25 nm to the volume of pores having a diameter of 1.2 nm or less is 0.04 or more and 0.45 or less. A PFAS removal material containing:

2. N at -196°C ２ The specific surface area determined by the BET method from the adsorption isotherm is 900 m ２ / g or more 1760m ２ / g or less, The pore volume (A) of pores with a pore diameter of 2 to 4 nm is 0.030 mL / g or more and 0.100 mL / g or less, The pore volume (B) of pores with a diameter of 1.2 nm or less is 0.230 mL / g or more and 0.350 mL / g or less, A PFAS removal material containing a carbonaceous material having a pore volume (C) of pores with diameters of 9 to 25 nm of 0.011 mL / g or more and 0.140 mL / g or less.

3. A PFAS removal material as described in claim 1 or 2, wherein the MS hardness of the carbonaceous material is 80.0% or more.

4. A PFAS removal material as described in claim 1 or 2, wherein the average particle size of the carbonaceous material is 0.15 mm or more and 1.70 mm or less.

5. A PFAS removal material as described in claim 1 or 2, wherein the pentavalent reactive black of the carbonaceous material is 2.0 g / L or more and 15.0 g / L or less.

6. A PFAS removal material as described in claim 1 or 2, wherein the packing density of the carbonaceous material is 0.350 g / mL or more and 0.550 g / mL or less.

7. An adsorption filter comprising the PFAS removal material according to claim 1 or 2.

8. A water purifier cartridge containing the PFAS remover according to claim 1 or 2.

9. A water purifier comprising the PFAS removal material according to claim 1 or 2.

10. A water purification facility comprising the PFAS removal material according to claim 1 or 2.

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