JP6579281B2 - Adsorbing member and manufacturing method thereof - Google Patents

Description

  The present invention relates to a water treatment adsorbing member used for adsorbing and removing contaminants.

  There is known a solution processing system that removes unnecessary components from a solution to make the solution more suitable for the purpose. In particular, water treatment systems for treating water are often used.

  In water treatment systems, separation membranes (reverse osmosis membranes, etc.) that remove substances to be separated from raw water (treated water) are used. When fouling occurs in the separation membrane, the substances to be separated are used. Separation performance for removing water from raw water is reduced.

  Therefore, in order to extend the exchange life of the separation membrane, a membrane clogging substance (foreign matter) that causes the degradation of the performance of the separation membrane is preliminarily adsorbed on the adsorption member provided in the previous stage of the separation membrane and selectively from raw water. A method of removing is known. For example, when processing water such as seawater, rivers, lakes, etc., dissolved organic matter can be cited as a main membrane clogging substance. Of the dissolved organic matter, polysaccharides are particularly viscous and are likely to clog the separation membrane, and therefore are required to be removed in advance.

  Japanese Patent Application Laid-Open No. 2012-91151 includes an outer wall, a plurality of flow paths provided inside the outer wall, and a partition wall that separates the plurality of flow paths, and the partition wall communicates with the adjacent flow paths. Disclosed is an adsorption structure that has pores and adsorbs organic matter in the water to be treated. The partition is made of alumina or a composite oxide containing alumina, and the surface of the partition or the communication hole surface in the partition The structure which formed the film containing an alumina is disclosed. Japanese Patent Application Laid-Open No. 2012-91151 describes that dissolved organic substances in the treated water can be adsorbed and removed by constituting a part of the partition walls with alumina.

  JP 2016-198742 includes an outer wall, a plurality of flow paths provided inside the outer wall, and a partition wall that separates each of the plurality of flow paths from each other, and the partition wall is formed between adjacent flow paths. An adsorption structure comprising a porous ceramic honeycomb structure having a plurality of communicating holes to be communicated and having at least the surface of the partition walls formed of alumina is disclosed. Japanese Patent Laid-Open No. 2016-198742 discloses that the adsorbing structure is one in which alumina is formed on a partition wall made of a ceramic such as cordierite, but the entire partition wall is formed of alumina. It is described as good. JP-A-2016-198742 discloses a method for forming alumina on a ceramic such as cordierite, and a slurry containing alumina is sucked into a porous ceramic body made of cordierite and then dried. A method of firing is described.

  However, the adsorption structure in which alumina is formed on a ceramic such as cordierite described in JP 2012-91151 A and JP 2016-198742 A, when alumina is coated on cordierite by firing, the alumina particles Depending on the composition of the binder, fine pores may be difficult to form, or the specific surface area may be significantly reduced by firing, so that the function as an adsorbent may not work sufficiently. In addition, the adsorption structure made of alumina as a whole of the partition walls cannot sufficiently increase the adsorption capacity because fine pores are hardly formed.

  International Publication No. 2015/199017 is an adsorbing member having an outer wall and a flow path provided inside the outer wall, into which water to be treated containing a hydrophilic substance and a hydrophobic substance is introduced, The flow path has an adsorbing portion having a member that adsorbs the hydrophilic substance and a member that adsorbs the hydrophobic substance, and a member that adsorbs the hydrophilic substance or a member that adsorbs the hydrophobic substance Is disclosed in the form of particles, and (a) the hydrophilic fine particles and the hydrophobic fine particles are combined with a surface of the partition wall and the communication holes using a binder such as an acrylic polymer or methyl cellulose. A method of fixing to the inner surface, (b) a method of fixing hydrophobic fine particles to the surface of the partition wall and the inner surface of the communication hole using an inorganic sol-based hydrophilic binder such as alumina sol or silica sol, and (c) hydrophilicity Fine particles, aromatic carboxylic acid and aromatic Using a hydrophobic binder of the mixed solution or the like and Min, describes a method of fixing to the inner surface of the surface and the communicating hole of the partition wall.

  However, in International Publication No. 2015/199017, the adsorbing member thus obtained does not sufficiently exhibit the adsorbing ability of the fine particles because the surface of the hydrophilic and hydrophobic fine particles is coated with a binder. Therefore, it is described that it is desirable to remove the binder covering the surface in advance, and extra work is required for use. In addition, by removing the binder, a part of the fine particles may be exfoliated and the adsorption capacity of the adsorption member may be reduced.

  On the other hand, WO 2015/083628 discloses a porous ceramic support made of metal oxide A, a filtration membrane layer made of metal oxide A particles coated on the surface of the support, and supported on the particle surface. The metal oxide B (which is different from the metal oxide A) is a ceramic that is a metal oxide in which the surface charge of the filtration membrane layer has the same polarity as the surface charge of the fouling-causing substance. A filter is disclosed. In this way, by supporting the metal oxide B having the same polarity as the surface charge of the fouling substance on the particle surface of the filtration membrane layer, the filter membrane layer surface of the filter and the fouling-causing substance are electrically repelled. Therefore, there is an advantage that clogging is difficult to occur and can be easily removed even once clogging occurs.

  However, the ceramic filter described in International Publication No. 2015/083628 basically has a pore blocking type filter that removes foreign matters by blocking foreign matters larger than the pore diameter by pores formed in the filter. Therefore, the pressure loss of the filter due to the fouling substance is inevitable.

  Accordingly, an object of the present invention is to provide an adsorbing member comprising a porous ceramic honeycomb structure excellent in adsorbing ability of dissolved organic substances such as polysaccharides.

  As a result of diligent research in view of the above object, the present inventors are composed of a base material made of porous ceramic and metal oxide particles fixed to at least a part of the surface of the base material and the inner surface of the communication hole. A porous ceramic honeycomb structure having a partition wall, wherein the total pore volume having a pore diameter of 10 to 200 nm measured by a mercury intrusion method is 0.1% or more per apparent volume of the partition wall, The inventors have found that the ability to adsorb dissolved organic substances (polysaccharides, etc.) in the water to be treated is remarkably excellent, and have arrived at the present invention.

That is, the adsorbing member of the present invention includes a plurality of axially extending flow paths partitioned by a porous partition wall, and adsorbs foreign matter in the treated water by passing the treated water through the plurality of flow paths. Consisting of a porous ceramic honeycomb structure to be removed,
The flow path is alternately plugged on the treated water inflow side or the treated water outflow side,
The partition is
Having communication holes connecting the flow paths;
A substrate made of porous ceramic;
It is composed of metal oxide particles fixed to at least a part of the surface of the base material and the inner surface of the communication hole,
The total pore volume having a pore diameter of 10 to 200 nm measured by a mercury intrusion method is 0.1% or more per apparent volume of the partition wall.

  The total pore volume having a pore diameter of 10 to 200 nm is preferably 1.0% or more, more preferably 8% or less, per apparent volume of the partition wall.

  In the adsorbing member, the volume-based median pore diameter measured by the mercury intrusion method (however, the volume-based median pore diameter is the total pore volume in a curve indicating the relationship between the pore diameter of the partition walls and the cumulative pore volume). Is the median pore diameter based on the surface area (however, the median pore diameter based on the surface area is the relationship between the pore diameter of the partition wall and the cumulative pore surface area). In the curve shown, it is preferably 50 to 5000 times the pore diameter at the pore surface area corresponding to 50% of the total pore surface area.

When the thickness of the partition wall is d and the width of the flow path is w,
d is 0.1-2 mm,
Formula: 0.20 ≦ d / w ≦ 1.25
It is preferable to satisfy.

The partition is
The porosity is 25 to 70%, and the volume-based median pore diameter measured by the mercury intrusion method (however, the volume-based median pore diameter is a curve indicating the relationship between the pore diameter of the partition wall and the cumulative pore volume, The pore diameter at a pore volume corresponding to 50% of the total pore volume.) Is preferably 1 to 50 μm, and preferably 0.005 to 0.15 times the thickness d of the partition wall.

  The metal oxide particles are preferably made of a material whose surface is positively charged when in contact with the water to be treated. The metal oxide particles are preferably made of a material having an isoelectric point of pH 8-10.

  The metal oxide is preferably alumina.

The partition is
A substrate made of porous cordierite;
Preferably, the substrate comprises alumina particles coated on at least a part of the surface of the substrate and the inner surface of the communication hole.

  The alumina is preferably α alumina or γ alumina. The alumina is preferably α-alumina.

The method for producing an adsorbing member of the present invention includes a plurality of axially extending flow paths partitioned by a porous partition wall, and allows the treated water to pass through the plurality of flow paths to remove foreign matters in the treated water. A method of manufacturing an adsorbing member for adsorbing and removing,
The clay containing the ceramic raw material is extruded into a predetermined molded body, and the molded body is dried and fired to form a ceramic honeycomb structure having a plurality of axially extending channels partitioned by porous partition walls. And a process of
Alternately forming plugged portions at the channel end of the ceramic honeycomb structure; and
Coating the partition walls of the ceramic honeycomb structure with metal oxide particles, drying and firing,
By coating the metal oxide particles, drying and firing, the partition wall has communication holes connecting the flow paths, and has a pore diameter of 10 to 200 nm measured by mercury porosimetry. The pore volume is 0.1% or more per apparent volume of the partition wall.

  The ceramic raw material is preferably a cordierite forming raw material.

  The metal oxide is preferably alumina.

  It is preferable to use alumina sol as an inorganic binder for coating the metal oxide particles.

  The firing temperature of the metal oxide particles is preferably 900 ° C. or lower.

  The adsorbing member of the present invention is suitable as a pretreatment for a treatment step using a separation membrane (such as a reverse osmosis membrane) in a water treatment system because it has an excellent ability to adsorb foreign substances such as dissolved organic matter. By adding the treatment using the adsorbing member of the present invention, it is possible to extend the life of the reverse osmosis membrane and reduce the running cost for water treatment.

It is a schematic diagram which shows the axial direction end surface of the ceramic honeycomb structure which comprises the adsorption | suction member of this invention. It is a schematic diagram which shows the cross section containing the central axis of the ceramic honeycomb structure which comprises the adsorption | suction member of this invention. It is a schematic diagram which shows the partition cross section of the ceramic honeycomb structure which comprises the adsorption | suction member of this invention. It is a schematic diagram which expands and shows the partition cross section of the ceramic honeycomb structure which comprises the adsorption | suction member of this invention. It is a schematic cross section for demonstrating the apparent volume of a partition. It is a flowchart which shows typically the water treatment facility using the adsorption | suction member of this invention. It is a schematic diagram which shows the adsorption | suction module incorporating the adsorption | suction member of this invention.

[1] Adsorption member
(1) Porous ceramic honeycomb structure As shown in FIGS. 1 to 3, the adsorbing member 1 of the present invention includes a plurality of flow paths 3 extending in the axial direction partitioned by porous partition walls 2, and the plurality The porous ceramic honeycomb structure 4 is configured to allow the water to be treated to pass through the flow path 3 and adsorb and remove foreign matters (dissolved organic substances and the like) in the water to be treated. The partition wall 2 has a communication hole 5 that connects between the adjacent flow paths 3, and is fixed to at least a part of the base material 6 made of porous ceramic, the surface 6a of the base material 6, and the inner surface 6b of the communication hole. The total pore volume having a pore diameter of 10 to 200 nm measured by a mercury intrusion method is 0.1% or more per apparent volume of the partition wall. To do.

  The porous ceramic honeycomb structure 4 is composed of an outer peripheral wall 8, a plurality of axially extending flow paths 3 provided inside the outer peripheral wall 8, and a partition wall 2 separating the plurality of flow paths 3. The partition wall 2 has a communication hole 5 that connects the adjacent flow paths 3 to each other.

  The plurality of flow paths 3 extending in the axial direction (longitudinal direction) of the porous ceramic honeycomb structure 4 are formed in a honeycomb shape, and one end of the porous ceramic honeycomb structure 4 (inflow side of the water to be treated) ) Or the other end (the outflow side of the treated water) have plugged portions 9a, 9b alternately, so that the end surface 10a on the inflow side of the treated water is opened and the treated water on the opposite side is opened. The first flow path 3a in which the end surface 10b on the outflow side is plugged by the plugging portion 9a, the end surface 10b on the outflow side of the treated water is opened, and the end surface 10a on the opposite inflow side is the plugging portion And a second flow path 3b plugged by 9b. The first flow path 3a and the second flow path 3b are alternately arranged both vertically and horizontally as viewed in the axial direction.

  The flow of the water to be treated when the water to be treated flows into the porous ceramic honeycomb structure 4 constituting the adsorbing member 1 will be described with reference to FIGS. The treated water that has flowed into the first flow path 3a that opens to the end face 10a on the inflow side passes through the fine communication holes 5 in the partition wall 2 and flows into the second flow path 3b, where the end face 10b on the outflow side Is discharged out of the adsorbing member 1 as treated water. When the water to be treated passes through the first flow path 3a and the second flow path 3b, and when passing through the fine communication hole 5 in the partition wall 2, the surface 6a of the base 6 of the partition wall 2 and the inner surface 6b of the communication hole It is possible to remove foreign matter from the water to be treated by contacting the metal oxide particles 7 fixed on the surface and adsorbing foreign matter (dissolved organic matter such as polysaccharides) in the water to be treated. it can.

(2) Partition Wall The partition wall 2 is composed of a base material 6 made of porous ceramic and metal oxide particles 7 fixed to at least a part of the surface 6a of the base material 6 and the communication hole inner surface 6b. . The metal oxide particles 7 need only be fixed to at least a part of the surface 6a and the communication hole inner surface 6b of the substrate 6, and are preferably fixed mainly to the communication hole 6b. When the water to be treated passes through the adsorbing member, the water to be treated has a metal oxide particle 7 fixed to the inner surface 6b of the communication hole rather than the metal oxide particle 7 fixed to the surface 6a of the substrate 6. Therefore, it is possible to efficiently adsorb and remove foreign substances such as dissolved organic substances by fixing more metal oxide particles 7 to the inner surface 6b of the communication hole.

  As shown in FIG. 4, the metal oxide particles 7 are preferably laminated and fixed on the surface 6a of the substrate 6 and the inner surface 6b of the communication hole. By having such a configuration, a large number of fine pores of 1 μm or less are formed, and an adsorbing member having a high specific surface area can be formed. For this reason, it becomes possible to efficiently adsorb and remove foreign substances such as dissolved organic matter in the water to be treated. That is, the partition wall 2 has a structure composed of relatively large pores constituting the communication holes 5 and fine pores of 1 μm or less formed by the metal oxide particles 7.

(a) Pore structure In the partition wall 2, the total pore volume having a pore diameter of 10 to 200 nm measured by mercury porosimetry is 0.1% or more per apparent volume of the partition wall. This value is the ratio of “total pore volume having a pore diameter of 10 to 200 nm” existing in “per apparent volume of partition wall”, and the pore volume of 10 to 200 nm per apparent volume of partition wall. It is also called the ratio. The pores having a pore diameter of 10 to 200 nm are mainly formed by the metal oxide particles 7 and greatly contribute to the adsorption of foreign substances (dissolved organic substances and the like) in the water to be treated. If the total pore volume having a pore diameter of 10 to 200 nm measured by the mercury intrusion method is less than 0.1% per apparent volume of the partition wall, is there not enough pores having a pore diameter of 10 to 200 nm? Since a large amount of the contact time with the water to be treated is present on the surface 6a of the substrate 6, the effect of adsorbing and removing dissolved organic matter is insufficient. The total pore volume having a pore diameter of 10 to 200 nm measured by the mercury intrusion method is preferably 0.5% or more, more preferably 1.0% or more, per apparent volume of the partition wall. Here, the apparent volume of the partition wall does not increase even when the metal oxide particles 7 are fixed to the communication hole inner surface 6b. Therefore, the metal oxide particles 7 are fixed more to the communication hole inner surface 6b than to the surface 6a of the substrate 6. In this case, the ratio of the pore volume of 10 to 200 nm per apparent partition wall volume becomes larger.

  The upper limit of the ratio of the pore volume of 10 to 200 nm per partition wall apparent volume is not particularly limited, but if this ratio is too large, excessively fixed metal oxide particles 7 narrow the communication holes 5 of the partition wall 2, Not only does the passage of the partition wall 2 of the water to be treated interfere, but it also does not contribute to an increase in the chance of contact between the water to be treated and the metal oxide particles 7. For this reason, the total pore volume having a pore diameter of 10 to 200 nm measured by mercury porosimetry is preferably 8% or less, more preferably 6% or less, per apparent volume of the partition wall. The apparent volume of the partition wall is the total volume of the communication holes 5, the base material 6 and the metal oxide particles 7 constituting the partition wall 2, as indicated by a frame 2s in FIG.

  Below, the mechanism by which metal oxides adsorb and remove dissolved organic substances such as polysaccharides will be briefly described. For example, in seawater desalination treatment, as described above, among organic substances dissolved in seawater, dissolved organic substances such as polysaccharides that selectively adhere to the reverse osmosis membrane and cause clogging are adsorbed and removed by pretreatment. It is hoped that. Many of these polysaccharides have an acidic group such as a carboxyl group and are therefore negatively charged in seawater. On the other hand, metal oxides such as alumina have hydroxyl groups on the surface due to adsorption of water in water, and the hydroxyl groups on the alumina surface usually have an isoelectric point near pH = 9. The surface of the alumina is positively charged in seawater with a nearby pH. Accordingly, the positively charged alumina can adsorb and remove dissolved organic substances such as polysaccharides. Further, since there are many oxygen atoms on the metal oxide such as alumina, the dissolved organic matter is adsorbed to the metal oxide by hydrogen bonds between these oxygen atoms and the hydroxyl group of the dissolved organic matter.

  Accordingly, the metal oxide particles 7 are preferably made of a material whose surface is positively charged when it comes into contact with the water to be treated, and in particular, a material having an isoelectric point of pH 8 to 10. If the isoelectric point is pH 8 or higher, the charge on the partition wall surface can be made positive in most of the treated water close to neutrality, and it becomes possible to adsorb and hold negatively charged organic substances. In addition, since seawater etc. show a little alkalinity, when processing such treated water, it is preferable to select a metal oxide having an isoelectric point such that the partition wall surface is positively charged in the treated water. For example, it is preferable to apply a metal oxide having an isoelectric point of 8.2 or higher.

  The upper limit of the isoelectric point of the metal oxide is preferably pH 10. In the case of an adsorbing member that adsorbs and removes foreign matter in the water to be treated as in the present invention, if the adsorption performance is reduced, the surface charge plus / minus is reversed during cleaning, and the adsorbed and retained foreign matter is removed from the surface. By separating, the adsorption performance of the adsorption member can be regenerated. When a metal oxide having an isoelectric point exceeding pH 10 is used, a sufficient repulsive force cannot be obtained by reversing the surface charge unless a stronger alkaline aqueous solution is used as a cleaning liquid. When strong alkali is used as the cleaning liquid, damage to the adsorbing member and other members increases. Therefore, in order to reduce the use of strong alkali as much as possible, the isoelectric point of the metal oxide is set to pH 10 or less.

  Examples of the metal oxide particles include α-alumina, γ-alumina, zinc oxide, and the like. Particularly preferred are α-alumina and γ-alumina which are excellent in the ability to adsorb dissolved organic matter. α-alumina is most preferable because it is excellent in corrosion resistance.

A typical example of a dissolved organic substance present in seawater is a polysaccharide. For example, when considering a molecule with a molecular weight of 1 million as a polysaccharide, its molecular size (assuming a sphere with a density of 1 g / cm ³ ) is about 15 nm, and when considering a molecule with a molecular weight of 5 million, The molecular size (assuming a sphere with a density of 1 g / cm ³ ) is about 30 nm. Therefore, if there are many pores having a pore diameter of 10 to 200 nm formed by the metal oxide particles 7, there will be many surfaces on which these dissolved organic substances can be adsorbed, and the dissolved organic substances can be adsorbed efficiently. It can be removed.

  In the mercury intrusion method, a partition sample in a vacuum state is immersed in mercury and pressurized, and the pore distribution is obtained by determining the relationship between the pressure during pressurization and the volume of mercury pushed into the pores of the sample. It is a method to ask for. In the measurement of the mercury intrusion method, when the pressure is gradually increased, mercury is injected in order from the pore having the largest diameter on the sample surface, and finally all the pores are filled with mercury. However, in practice, pores having a diameter of less than several nm may not be able to be measured accurately depending on the material. Therefore, in the present invention, the measurement values obtained for pores of 6 nm or more are used. The volume-based pore distribution (relationship between the pore diameter of the partition walls and the cumulative pore volume) was determined. Therefore, the total pore volume was a value obtained from the amount of mercury filled in pores of 6 nm or more.

  Here, the pore diameter at the time when 50% of the total volume of mercury is injected is the median pore diameter (volume basis) measured by the mercury intrusion method. Further, the relationship between the pore diameter of the partition walls and the cumulative pore surface area is obtained, and from the curve, the pore diameter at the pore surface area corresponding to 50% of the total pore surface area is obtained as the median pore diameter based on the surface area.

The volume-based median pore diameter D ₅₀ measured by the mercury intrusion method is preferably _{50 to} 5000 times the surface area-based median pore diameter d ₅₀ , that is, 50 ≦ D ₅₀ / d ₅₀ ≦ 5000. The volume-based median pore diameter D ₅₀ is a value mainly reflecting a relatively large pore structure such as pores forming communication holes in the partition walls, and is preferably in the range of 1 to 50 μm. On the other hand, when many pores having a pore diameter of 1 μm or less as formed by metal oxide particles are included, the median pore diameter d _{50 based on the} surface area is remarkably smaller than the median pore diameter D _{50 based on the} volume. Shift to the side. Therefore, when there are many pores having a pore diameter of 10 to 200 nm that are highly effective for adsorbing and removing dissolved organic substances, the value of D ₅₀ / d ₅₀ becomes larger. When the value of D ₅₀ / d ₅₀ is less than _50, the number of pores having a pore diameter of 10 to 200 nm is reduced, and the effect of adsorbing and removing dissolved organic substances is greatly reduced. When the value of D ₅₀ / d ₅₀ is more than 5000, there are many finer pores of less than 10 nm, and the effect of adsorbing dissolved organic matter is saturated. The value of D ₅₀ / d ₅₀ is more preferably from 100 to 2500, and most preferably from 150 to 1000.

As described above, the volume-based median pore diameter D ₅₀ is a value mainly reflecting the pores that form the communication holes in the partition walls, and is preferably in the range of 1 to 50 μm, and preferably 1 to 30 μm. More preferably, it is 5-25 micrometers, and it is most preferable that it is 10-20 micrometers. The volume-based median pore diameter D ₅₀ is preferably in the range of 0.005 to 0.15 times the partition wall thickness d. When the volume-based median pore diameter D ₅₀ is less than 1 μm and / or when it is less than 0.005 times the partition wall thickness d, the diameter of the communication hole becomes too small, so the resistance (pressure loss) when water passes through In addition, the clogging due to components other than the adsorbed component becomes significant, and may be damaged when a large pressure is applied to the water to be treated. When the volume-based median pore diameter D ₅₀ is more than ₅₀ μm and / or more than 0.15 times the partition wall thickness d, the area of the inner surface of the communication hole for fixing the metal oxide particles is too large because the pores are too large. Smaller and less metal oxide particles. As a result, the ability to adsorb dissolved organic matter decreases.

Since the adsorbing member of the present invention removes dissolved organic substances by adsorption, even if the volume-based median pore diameter D ₅₀ is in the range of 1 to ₅₀ μm, the dissolved member exists in water with a size of 10 to 20 nm. Organic matter can be removed. For this reason, unlike the pore-blocking filter (filter membrane) that removes foreign matters by blocking foreign matters larger than the pore diameter by the pores formed in the filter, it has a small pressure loss and high removal performance of dissolved organic matter. Can be compatible.

(b) Porosity The porosity of the partition wall 2 is preferably 25 to 70%. The porosity of the partition wall 2 is that the volume of the communication hole 5 in the partition wall 2 of the base material 6, the surface 6a of the base material 6 and the inner surface of the communication hole 6b, and the surface of the plugging portions 9a and 9b are made of metal oxide. It is calculated from the total volume of fine pores of 1 μm or less formed by coating the particles 7. Since the pore volume of the communication hole 5 is larger than the volume of fine pores of 1 μm or less formed by coating, the porosity is almost determined by the pore volume of the communication hole 5. When the porosity of the partition wall 2 is less than 25%, many pores that do not form the communication holes 5 exist, and the amount of the communication holes 5 decreases. When the porosity of the partition wall 2 is more than 70%, the mechanical strength of the partition wall 2 decreases, and there is a possibility that the partition wall 2 may be damaged when a large pressure is applied to the treated water.

(c) Structure The thickness d of the partition wall 2 is preferably 0.1 to 2 mm, and the ratio d / w between the thickness d and the width w of the flow path formed by the partition wall 2 is expressed by the formula: 0.20 ≦ d / It is preferable to satisfy w ≦ 1.25. When the thickness of the partition wall 2 is less than 0.1 mm and / or 0.20> d / w, the mechanical strength of the partition wall 2 is reduced, and there is a possibility that the partition wall 2 may be damaged when a large pressure is applied to the water to be treated. At the same time, the length of the communication hole 5 cannot be secured sufficiently, and the amount of metal oxide particles is reduced, so that the adsorption performance is lowered. When the thickness of the partition wall 2 exceeds 2 mm and / or d / w> 1.25, the pressure required to permeate the water to be treated increases (pressure loss increases), and the time and energy required for water treatment It takes. Note that the thickness d of the partition wall 2 and the width w of the flow path can be appropriately set by changing the dimensions of the molding die.

  Although not limited, the partition walls 2 are preferably provided in a lattice shape or a mesh shape as viewed in the axial direction. Therefore, for example, when the partition walls 2 are provided in a lattice shape, the flow path 3 has a quadrangular shape when viewed in the axial direction. In this case, the flow path 3 is preferably a quadrangle having a side of 0.5 to 8 mm as viewed in the axial direction. If one side of the flow path 3 is less than 0.5 mm, foreign matter other than dissolved organic matter in the water to be treated may block the flow path 3a that opens to the end surface 10a on the inflow side of the ceramic honeycomb structure 4, and the processing capacity Decreases. On the other hand, when one side of the flow path 3 exceeds 8 mm, the mechanical strength becomes insufficient unless the partition wall 2 of the ceramic honeycomb structure 4 is sufficiently thick, and a large pressure is applied to the water to be treated. The possibility of breakage increases. The shape of the flow path 3 is not limited to a regular square as shown in FIG. 1, and may be a shape that can be filled on a plane such as another square, a triangle, a hexagon, a combination of an octagon and a square, or the like. .

(d) Material The base material 6 of the partition wall 2 is made of a ceramic mainly composed of alumina, silica, cordierite, titania, mullite, zirconia, spinel, silicon carbide, silicon nitride, aluminum titanate, lithium aluminum silicate, or the like. Is preferred. In particular, the substrate 6 is preferably alumina or cordierite, and most preferably cordierite. As cordierite, the main crystal phase may be cordierite, and may contain other crystal phases such as spinel, mullite, sapphirine, and further glass components. Therefore, the adsorbing member of the present invention is preferably composed of a base material made of porous cordierite and alumina particles coated on at least a part of the surface of the base material and the inner surface of the communicating hole.

  In the present invention, the base material of the partition walls is preferably cordierite, and the metal oxide particles are preferably alumina. Cordierite is a base material on which pores can be easily formed, and contains alumina as a component, and is therefore effective for firmly fixing alumina.

(3) Plugged portion The plurality of flow paths 3 of the ceramic honeycomb structure 4 are alternately plugged on the treated water inflow side or the treated water outflow side, and as a result, the end surface of the treated water inflow side The first flow path 3a in which the end surface 10b on the opposite side of the treated water outflow side is plugged by the plugging portion 9a and the end surface 10b on the outflow side of the treated water is opened on the opposite side The end surface 10a on the inflow side of the water to be treated has the second flow path 3b plugged by the plugging portion 9b. The first flow path 3a and the second flow path 3b are arranged so as to be adjacent to each other via the single partition wall 2, and the water to be treated flowing from the first flow path 3a is separated from the partition wall 2. The treated water is configured to be discharged from the second flow path 3b through the communication hole therein.

  The plugging portions 9a and 9b may be formed of the same material as the porous ceramic honeycomb structure 4 (base material 6 of the partition wall 2), an organic material, a material that does not dissolve in the treated water, such as other inorganic materials. it can. When the porous ceramic honeycomb structure 4 is formed of the same material, it can be formed by pouring a slurry made of a ceramic material into a predetermined end of the flow path and firing it. Examples of the organic material include polyimide, polyamide, polyimide amide, polyurethane, acrylic, epoxy, polypropylene, Teflon (registered trademark), and other inorganic materials include ceramics other than the ceramic that forms the partition 2 ( Alumina, silica, magnesia, titania, zirconia, zircon, cordierite, spinel, aluminum titanate, lithium aluminum silicate, etc.) and glass. A known method can be used to form the plugged portions 9a and 9b.

  The porosity of the plugged portions 9a and 9b is preferably 0 to 40%, and is preferably smaller than the porosity of the partition wall 2. Further, it is desirable that the axial lengths of the plugged portions 9a and 9b are thicker than the thickness of the partition wall 2. When the porosity of the material used for the plugging portions 9a and 9b exceeds 40% or is larger than the porosity of the partition walls 2, the water to be treated passes through not only the partition walls 2 but also the plugging portions 9a and 9b. The dissolved organic matter is discharged from the adsorbing member without being adsorbed by the metal oxide particles 7.

[2] Method for producing adsorption member The method for producing the adsorption member of the present invention comprises:
The clay containing the ceramic raw material is extruded into a predetermined molded body, and the molded body is dried and fired to form a ceramic honeycomb structure having a plurality of axially extending channels partitioned by porous partition walls. And a process of
Alternately forming plugged portions at the channel end of the ceramic honeycomb structure; and
Coating the partition walls of the ceramic honeycomb structure with metal oxide particles, and drying and firing.

(1) Formation of Porous Ceramic Structure A method for forming the porous ceramic structure 4 will be described by taking the case of the porous ceramic structure 4 made of cordierite as an example. Kaolin, talc, silica, were prepared powders such as alumina, SiO ₂ in a weight _{ratio: 48~52%, Al 2 O 3} : 33~37%, and MgO: 12 to 15% become so cordierite Prepare powdered raw material powder, add binder such as pore former, methylcellulose, hydroxypropylmethylcellulose, etc., and add additives such as dispersant, surfactant, lubricant, etc. Add water and knead to make a plasticized ceramic clay. Next, the clay is extruded using a molding die, cut, cut and dried, and the end face and outer periphery are processed as necessary to obtain a dried body having a honeycomb structure. After the dried body is fired (for example, 1400 ° C.), a coating agent containing cordierite particles and colloidal silica is applied to the outer periphery and fired, and the cross section partitioned by the partition walls 2 inside the outer peripheral wall 8 A cordierite porous ceramic honeycomb structure 4 in which a large number of rectangular channels 3 are formed. The formation of the outer peripheral wall 8 may be performed after the formation of a plugging portion described later.

(2) Formation of plugging portion A binder and a dispersion medium (solvent) are added to the cordierite forming raw material powder used for the production of the porous ceramic structure 4 to prepare a plugging portion forming slurry. . The slurry is provided with a plurality of nozzles so as to alternately plug the treated water inflow side end and the treated water outflow side end of the flow path 3 into the flow path 3 of the porous ceramic honeycomb structure 4. Then, the plugging portions 9a and 9b are formed by drying and baking.

  In addition to the dispenser, a screen printing method can be used for forming the plugged portions 9a and 9b. When using the screen printing method, a print mask having an opening at a predetermined position is arranged in accordance with a predetermined position of the ceramic honeycomb structure 4, and a high-viscosity slurry is injected through the opening of the print mask, and then Then, the plugged portions 9a and 9b are formed by drying and firing.

  The plugging portions 9a and 9b may be formed of the same material as that of the porous ceramic honeycomb structure 4 or may be formed of a different ceramic material. Organic polymer materials (polyimide, polyamide, polyimide amide, polyurethane, acrylic, epoxy, polypropylene, Teflon (registered trademark), etc.), inorganic materials (glass, etc.) or ceramic particles (alumina, silica, magnesia, titania, zirconia, zircon) , Cordierite, spinel, aluminum titanate, lithium aluminum silicate, etc.) and a composite material composed of the above organic polymer material. For example, the plugged portions 9a and 9b may be formed by pushing and fixing a stopper prepared in advance using a material such as Teflon (registered trademark) with a stick or syringe. When an organic polymer material is used, the temperature for forming the plugging portions 9a and 9b is set lower than the temperature for forming the partition walls 2.

(3) Coating of metal oxide particles After the formation of plugging portions 9a and 9b, the surface 6a of the base 6 of the partition wall 2 of the porous ceramic honeycomb structure 4 and the inner surface 6b of the communication hole, and the plugging portion 9a The surface of 9b is coated with metal oxide particles 7. The coating of the metal oxide particles 7 can be performed by a so-called known washcoat method. A slurry containing metal oxide particles 7 (for example, α-alumina, γ-alumina) is sucked and supplied into the porous ceramic honeycomb structure 4, and then dried and fired at 900 ° C. or lower. . An inorganic binder such as alumina sol can be added to the slurry. When firing at a temperature higher than 900 ° C., the crystallites in the alumina sol or γ-alumina grows to form coarse particles, which is not preferable. In order to obtain an adsorbing member having fine pores of 1 μm or less formed by metal oxide particles, the firing temperature after coating the metal oxide particles is 900 ° C. or less.

  As the metal oxide particles 7 to be coated, for example, alumina powder having an average particle size of 0.1 to 1 μm is preferably used. Examples of such alumina powder include pulverized alumina A-26 manufactured by Sumitomo Chemical. As the binder, alumina sol having an average particle size of 100 to 500 nm is preferable, and specifically, the Cataloid AS series manufactured by JGC Catalysts & Chemicals is exemplified.

  The coating amount of the metal oxide particles 7 on the base material 6 of the partition wall 2 is preferably 0.2 to 5 μm as the thickness of the metal oxide particles 7 formed after firing, and is preferably 0.5 to 2 μm. More preferred. The total pore volume having fine pores of 1 μm or less formed by metal oxide particles and having a pore diameter of 10 to 200 nm measured by mercury porosimetry is 0.1% or more per apparent volume of the partition wall. In order to obtain the adsorbing member, the thickness of the metal oxide particles after firing is 0.2 μm or more. The coating amount can be adjusted by the viscosity of the slurry, the particle concentration of the metal oxide, and the like. If a predetermined amount of metal oxide particles is not coated at one time, the wash coat method may be repeated a plurality of times.

[3] Water Treatment Facility The adsorbing member 1 of the present invention is used in, for example, a water treatment facility 100 as shown in the flowchart in FIG. The water treatment facility 100 includes an adsorption module 101 incorporating the adsorption member 1 of the present invention, a water storage tank 102 for storing water treated by the adsorption module 101, a water supply pump 103 for supplying water from the water storage tank 102, and a water supply And a reverse osmosis membrane module 104 having a reverse osmosis membrane 105 for removing a substance to be separated from water sent from the pump 103.

  A suction module 101 incorporating the suction member 1 of the present invention is shown in FIG. The adsorbing module 101 includes the adsorbing member 1 of the present invention, a filter support 110 that supports the treated liquid inflow side end surface and the treated water outflow side end surface of the adsorbing member 1 via a gripping member (not shown), A housing 111 (for example, an acrylic container) that houses the adsorbing member 1 and the filter support 110 is configured. The filter support 110 may be of a material and a material that can pass through the water to be treated without resistance, has a strength that does not easily deform due to the pressure of the water to be treated, and does not have an eluate into the water. For example, a resin mesh spacer such as polyethylene, polypropylene, polyethylene terephthalate, or polystyrene, a metal mesh such as stainless steel or titanium, or a punching metal can be used.

  The adsorption module 101 is subjected to a primary process such as a process of removing dust etc. through a screen, a process of adding fine flocculant such as sand to settle and removing it, and a process of decomposing organic matter using microorganisms. Water is supplied, and this primary treated water contains salts and dissolved organic matter. The primary treated water supplied to the adsorption module 101 passes through the adsorption member 1 to adsorb and remove foreign matter (dissolved organic matter, etc.) in the treated water, and reverse osmosis while being pressurized by the water supply pump 103 via the water storage tank 102. The membrane 105 is separated into permeated water from which organic substances and salts in the treated water have been removed and concentrated water from which organic substances and salts have been concentrated. By adsorbing and removing foreign substances (dissolved organic substances, etc.) in the primary treated water by the adsorbing member 1, clogging of the reverse osmosis membrane 105 can be prevented and the replacement life of the reverse osmosis membrane 105 can be extended.

  Since the adsorbing member 1 of the present invention functions as a pretreatment step for selectively and efficiently removing organic substances adhering to the surface of the reverse osmosis membrane 105, such a water treatment facility 100 is used for seawater desalination, semiconductor Water treatment using reverse osmosis membrane 105, such as pure water production used in the manufacture of precision electronic equipment such as advanced water treatment, sewage and wastewater regeneration treatment (including those not combined with microbial treatment), especially seawater Applicable to desalination process.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(1) Preparation of adsorption member The adsorption members of the example (the present invention) and the comparative example were produced as follows.

Example 1
Kaolin, talc, silica, by adjusting the powder of aluminum hydroxide and alumina, cordierite-forming raw material powder chemical composition is 50% by weight of SiO _2, 36 wt% of Al ₂ O ₃ and 14% by weight of MgO Got. To this cordierite-forming raw material powder, methylcellulose and hydroxypropylmethylcellulose are added as molding aids, and thermally expandable microcapsules are added as a pore-forming material, a prescribed amount of water is injected, and sufficient mixing is performed to obtain a honeycomb structure. An extrudable clay was prepared.

  The obtained kneaded material was extruded using a molding die to produce a honeycomb structure molded body. After drying, the peripheral portion was removed and fired at 1400 ° C. for 24 hours. A plugging material made of cordierite forming raw material so that the treated water inflow side end portion or the treated water outflow side end portion of the flow path of the ceramic honeycomb body after firing is alternately plugged. After filling the slurry, the plugging material slurry was dried and fired. The outer periphery of the ceramic honeycomb structure after forming the plugged portions is coated with a coating agent containing cordierite particles and colloidal silica, dried and fired to form an outer peripheral wall. A porous ceramic honeycomb structure having a thickness of 0.3 mm, a partition wall thickness of 0.3 mm, and a cell pitch of 1.6 mm was obtained.

  The porous ceramic honeycomb structure in which the plugged portions are formed is immersed in a slurry containing alumina fine particles originating from γ-alumina and an alumina sol binder, and is inserted into the communication holes formed in the partition walls of the porous ceramic honeycomb structure. After sufficiently infiltrating the slurry, it is taken out from the slurry, dried, and fired at 500 ° C. for 5 hours to form the base material surface of the partition wall of the porous ceramic honeycomb structure, the inner surface of the communication hole, and the surface of the plugging portion. The adsorption member of the present invention was produced by coating metal oxide particles (alumina fine particles). The layer of coated alumina particles had a thickness in the range of 0.2-1 μm. The coated alumina was confirmed to be α-alumina by electron diffraction.

Example 2
An adsorbing member of the present invention was produced in the same manner as in Example 1 except that alumina fine particles originating in α-alumina were used instead of the alumina fine particles originating in γ-alumina used in Example 1. The layer of coated alumina particles had a thickness in the range of 0.3 to 0.8 μm. The coated alumina was confirmed to be α-alumina by electron beam diffraction.

Example 3
An adsorbing member of the present invention was produced in the same manner as in Example 1 except that alumina fine particles originating in another γ alumina were used instead of the alumina fine particles originating in γ alumina used in Example 1. The layer of coated alumina particles had a thickness in the range of 0.5 to 1.5 μm. The coated alumina was confirmed to be α-alumina by electron beam diffraction.

Comparative Example 1
Add enough methyl cellulose and hydroxypropyl methylcellulose as molding aids to α-alumina powder, and add spherical resin with hollow inside structure and average particle size of 10-45μm as pore former, inject a specified amount of water, and knead thoroughly To prepare a clay that can be extruded into a honeycomb structure. The obtained kneaded material was extruded using a molding die to produce a honeycomb structure molded body. After drying, the peripheral portion was removed and fired at 1400 ° C. for 24 hours. In the same manner as in Example 1, cordierite is formed so that the treated water inflow side end or the treated water outflow side end of the flow path is alternately plugged into the flow path of the fired ceramic honeycomb body. After filling the plugging material slurry made of the raw material, the plugging material slurry was dried and fired. The outer periphery of the ceramic honeycomb structure after forming the plugged portions is coated with a coating agent containing cordierite particles and colloidal silica, dried and fired to form an outer peripheral wall. A porous ceramic honeycomb structure made of alumina having a thickness of 0.7 mm, a partition wall thickness of 0.76 mm, and a cell pitch of 2.66 mm was produced as an adsorbing member. The metal oxide particles were not coated, and the thickness of the metal oxide particles was 0 μm.

Comparative Example 2
An adsorbing member made of porous cordierite was produced in the same manner as in Example 1 except that alumina was not coated on the partition wall surface and the communication holes. The metal oxide particles were not coated, and the thickness of the metal oxide particles was 0 μm.

Comparative Example 3
The adsorbing member obtained in Example 1 was further baked at 1400 ° C. for 24 hours to produce an adsorbing member. The layer of alumina particles had a thickness in the range of 0.2 to 1 μm before firing at 1400 ° C., but the surface of the ceramic honeycomb structure reacted with the alumina particles by firing at 1400 ° C. The thickness of the integrated layer of alumina particles was less than 0.2 μm.

(2) Evaluation of pore structure The pore distribution of the obtained adsorbing member was measured by a mercury intrusion method. In the mercury intrusion measurement, a test piece (10 mm x 10 mm x 10 mm) cut out from a porous ceramic honeycomb structure after coating with metal oxide particles was placed in a measurement cell of Autopore III manufactured by Micromeritics. After storing and depressurizing the inside of the cell, mercury was introduced and pressurized, and the relationship between the pressure at the time of pressurization and the volume of mercury pushed into the pores present in the test piece was determined. From the relationship between the pressure and the volume, the relationship between the pore diameter and the cumulative pore volume was determined. The pressure for introducing mercury is 0.5 psi (0.35 × 10 ^-3 kg / mm ² ), and the constants for calculating the pore diameter from the pressure are values of contact angle = 130 ° and surface tension = 484 dyne / cm did.

In the present application, measurement by mercury porosimetry was performed for pores of 6 nm or more, and pores having a smaller size were not considered. Therefore, the total pore volume is the total pore volume having a pore diameter of 6 nm or more. From the relationship between the pore size and the cumulative pore volume (volume-based pore distribution data), the pore size at the pore volume corresponding to 50% of the total pore volume is the volume-based median pore size (D ₅₀ ). As sought. Further, the total pore volume having a pore diameter of 10 to 200 nm was determined from the volume-based pore distribution, and indicated as a ratio per apparent volume of the partition walls.

Furthermore, from the volume-based pore distribution data, the relationship between the pore diameter of the partition walls and the cumulative pore surface area (surface area-based pore distribution data) is obtained, and the curve corresponds to 50% of the total pore surface area. The pore diameter at the pore surface area was determined as the median pore diameter (d ₅₀ ) based on the surface area. The porosity was calculated from the measured value of the total pore volume by setting the true specific gravity of cordierite to 2.52 g / cm ³ .

注1：隔壁の見かけ体積当たりに占める10〜200 nmの細孔径を有する全細孔容積の割合

Note 1: Percentage of total pore volume having a pore diameter of 10 to 200 nm per apparent volume of partition walls

(3) Evaluation of adsorption performance The adsorption performance of the adsorbing members of Examples 1 to 3 and Comparative Examples 1 to 3 with respect to dissolved organic substances was evaluated as follows. Mannan, one of the polysaccharides, is dissolved in artificial seawater at a concentration of 6 mg / L to prepare a liquid to be treated, and the 25 mm diameter and 35 mm long adsorbing member incorporated in the adsorption module as shown in Fig. 7 The liquid to be treated was supplied at a volume flow rate (SV) of 120 L / hr. The amount of mannan adsorbed on the adsorbing member by measuring the amount (carbon weight) of mannan in the liquid to be treated at the inlet and outlet of the adsorption module with a TOC (total organic carbon) measuring instrument (TOC-L manufactured by Shimadzu Corporation) (Carbon weight) was calculated, and the cumulative adsorption amount for 90 minutes was evaluated as the adsorption performance. If the adsorption amount evaluated under the above-described adsorption performance evaluation conditions is 1.0 mg or more, it is possible to design a water treatment facility with practically acceptable cost and size. The results are shown in Table 3.

注1：被処理液を90分間処理したときの吸着部材当たりの累積吸着量

Note 1: Cumulative amount of adsorption per adsorption member when the liquid to be treated is treated for 90 minutes

  From Table 2 and Table 3, the adsorbing members of Examples 1 to 3 in which the total pore volume having a pore diameter of 10 to 200 nm is 0.1% or more per apparent volume of the partition wall, the adsorbing amount is 1.0 mg or more. It can be seen that the adsorption performance for dissolved organic matter is excellent. In addition, in Examples 2 and 3, in which the total pore volume having a pore diameter of 10 to 200 nm is 1.0% or more per apparent volume of the partition wall, the adsorption amount is 1.5 mg or more, and the adsorption performance is excellent. Recognize.

(4) Water treatment using the adsorbing member of the present invention A powder of kaolin, talc, silica, aluminum hydroxide and alumina is prepared to have a chemical composition of 50% by mass of SiO ₂ , 36% by mass of Al ₂ O ₃ and A cordierite-forming raw material powder having 14% by mass of MgO was obtained. To this cordierite-forming raw material powder, methylcellulose and hydroxypropylmethylcellulose are added as molding aids, and thermally expandable microcapsules are added as a pore-forming material, a prescribed amount of water is injected, and sufficient mixing is performed to obtain a honeycomb structure. An extrudable clay was prepared.

  The obtained kneaded material was extruded using a molding die to produce a honeycomb structure molded body. After drying, the peripheral portion was removed and fired at 1400 ° C. for 24 hours. A plug made of a cordierite forming raw material is alternately plugged at the end of the flow path of the ceramic honeycomb body after firing so that the end of the water to be treated inflow side or the end of the treated water outflow side is plugged. After filling the stop material slurry, the plugging material slurry was dried and fired. The outer periphery of the ceramic honeycomb structure after forming the plugged portions is coated with a coating agent containing cordierite particles and colloidal silica, dried and fired to form an outer peripheral wall. A porous ceramic honeycomb structure having a thickness of mm, a partition wall thickness of 0.8 mm, and a cell pitch of 1.9 mm was obtained.

  The base material surface of the partition wall and the inner surface of the communication hole of the obtained porous ceramic honeycomb structure were coated with metal oxide particles (alumina fine particles) in the same manner as in Example 3 to obtain the adsorbing member of the present invention. . The layer of coated alumina particles had a thickness in the range of 0.5 to 1.5 μm. The coated alumina was confirmed to be α-alumina by electron beam diffraction.

Water treatment system A (example of the present invention)
In order to verify the fouling suppression effect of the reverse osmosis membrane by the produced adsorbing member, we installed actual seawater and a demonstration facility that can add sewage to it. Seawater added with sewage is used as raw water, and pretreatment is performed by combining the adsorbing material obtained by cheap sand filtration (SF) (sand filtration (SF) + adsorbing material), and the treated water is transferred to the reverse osmosis membrane module. A line A was prepared.

Water treatment system B (comparative example)
Seawater added with sewage was used as raw water for pretreatment with an existing ultrafiltration membrane (UF), and system B was prepared so that the treated water was sent to the reverse osmosis membrane module.

Water treatment system A '(comparative example)
Instead of the pretreatment (sand filtration (SF) + adsorbing member) used in the system A, a system A ′ changed to a pretreatment only with sand filtration (SF) was prepared.

Using these water treatment systems A, B and A ′, an operation for producing 1.7 m ³ / day of fresh water from seawater to which sewage was added was performed for 2 weeks. However, for system A, 20 L of an aqueous NaOH solution (0.1% by mass) was flowed only on the adsorbing member once a day for 10 minutes, and alkali cleaning was performed.

  By measuring the pressure increase of the reverse osmosis membrane after 2 weeks, the fouling suppression effect in the reverse osmosis membrane of each system was comparatively evaluated. As a result, about 15% of the pressure rises in the system B in which the pretreatment using only the ultrafiltration membrane (UF) is performed without using the adsorbing member of the present invention, and sand filtration (SF) without using the adsorbing member of the present invention. Only about 30% of the pressure was increased in the system A ′ which was pre-treated alone. On the other hand, no increase in pressure was observed in the system A subjected to the pretreatment with the adsorbing member of the present invention. Therefore, it was confirmed that the pretreatment with the adsorbing member of the present invention has a large effect of suppressing fouling of the reverse osmosis membrane.

Claims (15)

A porous ceramic honeycomb structure having a plurality of axially extending flow paths partitioned by porous partition walls, and allowing the treated water to pass through the plurality of flow paths to adsorb and remove foreign substances in the treated water An adsorbing member comprising:
The flow path is alternately plugged on the treated water inflow side or the treated water outflow side,
The partition is
Having communication holes connecting the flow paths;
A substrate made of porous ceramic;
It is composed of metal oxide particles fixed to at least a part of the surface of the base material and the inner surface of the communication hole,
The metal oxide particles are alumina particles having an average particle size of 0.1 to 1 μm,
The total pore volume having a pore diameter of 10 to 200 nm measured by a mercury intrusion method is 0.1% or more per apparent volume of the partition wall ,
Volume-based median pore diameter measured by the mercury intrusion method (however, the volume-based median pore diameter corresponds to 50% of the total pore volume in the curve showing the relationship between the pore diameter of the partition wall and the cumulative pore volume) Is the median pore diameter based on the surface area (however, the median pore diameter based on the surface area is a curve indicating the relationship between the pore diameter of the partition wall and the cumulative pore surface area). An adsorbing member having a pore diameter at a pore surface area corresponding to 50% of the pore surface area . In the adsorption member according to claim 1,
The adsorbing member, wherein a total pore volume having a pore diameter of 10 to 200 nm is 1.0% or more per apparent volume of the partition wall. In the adsorption member according to claim 1 or 2,
The adsorbing member, wherein a total pore volume having a pore diameter of 10 to 200 nm is 8% or less per apparent volume of the partition wall. In the adsorption member according to any one of claims 1 to 3 ,
When the thickness of the partition wall is d and the width of the flow path is w,
d is 0.1-2 mm,
Formula: 0.20 ≦ d / w ≦ 1.25
The adsorption member characterized by satisfying. In the adsorption member according to any one of claims 1 to 4 ,
The partition is
Porosity of 25% to 70%, and median pore diameter of the volume reference was measured by mercury porosimetry is 1 to 50 [mu] m, the adsorption member, which is a 0.005 to 0.15 times the thickness d of the partition wall. In the adsorption member according to any one of claims 1 to 5 ,
An adsorption member, wherein the metal oxide particles are made of a material whose surface is positively charged when it comes into contact with the water to be treated. In the adsorption member according to claim 6 ,
An adsorption member, wherein the metal oxide particles are made of a material having an isoelectric point of pH 8-10. In the adsorption member according to any one of claims 1 to 7 ,
The partition is
A substrate made of porous cordierite;
An adsorption member comprising alumina particles coated on at least a part of the surface of the base material and the inner surface of the communication hole. In the adsorption member according to any one of claims 1 to 8 ,
The adsorption member, wherein the alumina is α alumina or γ alumina. In the adsorption member according to claim 9 ,
The adsorption member, wherein the alumina is α-alumina. A method of manufacturing an adsorbing member that includes a plurality of axially extending flow paths partitioned by a porous partition wall, and that allows the treated water to pass through the plurality of flow paths to adsorb and remove foreign substances in the treated water. There,
The clay containing the ceramic raw material is extruded into a predetermined molded body, and the molded body is dried and fired to form a ceramic honeycomb structure having a plurality of axially extending channels partitioned by porous partition walls. And a process of
Alternately forming plugged portions at the channel end of the ceramic honeycomb structure; and
Coating the partition walls of the ceramic honeycomb structure with alumina powder having an average particle size of 0.1 to 1 μm , and drying and firing.
By coating the alumina powder , drying and firing, the partition wall has a communication hole connecting the flow paths, and a total pore volume having a pore diameter of 10 to 200 nm measured by mercury porosimetry. Is made 0.1% or more per apparent volume of the partition wall. In the manufacturing method of the adsorption member according to claim 11 ,
The method for producing an adsorbing member, wherein the ceramic raw material is a cordierite forming raw material. In the method for producing an adsorption member according to claim 11 or 12 ,
A method of manufacturing an adsorbing member, wherein alumina sol is used as an inorganic binder for coating the alumina powder . In the manufacturing method of the adsorption member according to any one of claims 11 to 13 ,
The method for producing an adsorbing member, wherein the firing temperature of the alumina powder is 900 ° C. or lower.   In the manufacturing method of the adsorption member according to claim 14,
A method for producing an adsorbing member, wherein the firing temperature of the alumina powder is 500 ° C.

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