WO2019027047A1

WO2019027047A1 - Adsorption member and production method therefor

Info

Publication number: WO2019027047A1
Application number: PCT/JP2018/029284
Authority: WO
Inventors: 石澤　俊崇; 佐伯　智則; 未映子菓子; 敬子中野
Original assignee: 日立金属株式会社
Priority date: 2017-08-04
Filing date: 2018-08-03
Publication date: 2019-02-07
Also published as: JP6579281B2; JPWO2019027047A1

Abstract

An adsorption member having a porous ceramic honeycomb structure including a plurality of flow channels separated by porous partition walls and extending in an axial direction, wherein water to be treated is passed through the plurality of flow channels so that foreign matter within the water to be treated is adsorbed and removed. The adsorption member is characterized in that: in the flow channels, the side into which the to-be-treated water flows and the side from which the treated water flows are alternately sealed; the partition walls have connection holes through which the flow channels are connected; the partition walls are formed of a base material made of porous ceramic, and metal oxide particles fixed to at least a portion of the inner surfaces of the communication holes and the surface of the base material; and the total volume of pores having a pore diameter of 10-200 nm as measured by mercury intrusion is 0.1% or more per apparent volume of the partition walls.

Description

Adsorption member and method of manufacturing the same

The present invention relates to a water treatment adsorptive member used to adsorb and remove contaminants.

Solution processing systems are known which remove unnecessary components from the solution to make the solution more suitable for the purpose. Among them, a water treatment system that treats water in particular is widely used.

The water treatment system uses a separation membrane (reverse osmosis membrane etc.) for removing the substance to be separated from the raw water (water to be treated), but if fouling (clogging) occurs in the separation membrane, the substance to be separated is The separation performance to remove water from raw water is reduced.

Therefore, in order to extend the exchange life of the separation membrane, a membrane clogging substance (foreign substance) causing deterioration of the performance of the separation membrane is adsorbed beforehand to the adsorption member provided in the previous stage of the separation membrane to selectively select from raw water Methods for removal are known. For example, when processing water such as seawater, rivers, lakes, etc., the main membrane clogging substances include dissolved organic matter. Among the dissolved organic substances, polysaccharides are particularly viscous and easily clog the separation membrane, and therefore, are required to be removed in advance.

Unexamined-Japanese-Patent No. 2012-91151 is provided with the outer wall, the several flow path provided inside the said outer wall, and the partition which separates the said several flow path, The said partition connects the communication which connects the said adjacent flow path. An adsorption structure having pores and adsorbing an organic substance in the water to be treated is disclosed, wherein the partition wall is made of alumina or a composite oxide containing alumina, and the surface of the partition wall or the communication hole surface within the partition wall Disclosed is a configuration in which a coating containing alumina is formed. Japanese Patent Laid-Open No. 2012-91151 describes that dissolved organic matter in treated water can be adsorbed and removed by forming a part of the partition with alumina.

JP-A-2016-198742 includes an outer wall, a plurality of flow channels provided inside the outer wall, and a partition separating each of the plurality of flow channels from each other, and the partition is disposed between adjacent flow channels. The adsorption | suction structure which has several communicating holes to make it connect and which consists of a porous ceramic honeycomb structure by which the at least surface of the said partition was formed with the alumina is disclosed. According to JP-A-2016-198742, even if alumina is formed on a partition made of ceramic such as cordierite as the adsorption structure, the entire partition is formed of alumina. Also stated that it is good. As a method of forming alumina on ceramic such as cordierite, JP-A-2016-198742 sucks and supplies a slurry containing alumina into the inside of the ceramic porous body made of cordierite and then dries it. The method of baking is described.

However, an adsorption structure in which alumina is formed on a ceramic such as cordierite described in JP-A-2012-91151 and JP-A-2016-19872 is an alumina particle when alumina is coated on cordierite by firing. Depending on the composition of the binder, fine pores may not be easily formed, or the specific surface area may be significantly reduced by firing, so that the function as an adsorbent may not work sufficiently. In addition, in the adsorption structure in which the whole partition wall is made of alumina, fine pores can not be easily formed, and therefore the adsorption capacity can not be sufficiently enhanced.

WO 2015/199017 is an adsorptive member having an outer wall and a flow path provided inside the outer wall, into which treated water 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 the member that adsorbs the hydrophilic substance or a member that adsorbs the hydrophobic substance Discloses an adsorption member formed in the form of particles, and (a) hydrophilic fine particles and hydrophobic fine particles, using a binder such as an acrylic polymer and methyl cellulose, on the surface of the partition wall and the communication holes 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 communicating hole using an inorganic sol-based hydrophilic binder such as alumina sol or silica sol, and (c) hydrophilicity Fine particles, aromatic carboxylic acid and aroma Described is a method of fixing on the surface of the partition wall and the inner surface of the communicating hole by using a hydrophobic binder such as a mixed solution with a group amine.

However, according to WO 2015/199017, in the adsorption member thus obtained, the surface of hydrophilic and hydrophobic particles is coated with a binder so that the adsorption ability of the particles is not sufficiently exhibited. Therefore, it is described that it is desirable to remove the binder covering the surface beforehand, and extra work is required for use. In addition to that, 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, in WO 2015/083628, a porous ceramic support made of metal oxide A, a filtration membrane layer made of particles of metal oxide A coated on the surface of the support, and a particle supported on the particle surface A ceramic comprising a metal oxide B (different from metal oxide A), the metal oxide B having the same polarity as the surface charge of the fouling agent as the surface charge of the filtration membrane layer Disclosed filter. Thus, 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 filtration membrane layer surface of the filter and the fouling-causing substance electrically repel each other. As a result, it has the advantage of being less likely to cause clogging and of being easily removable once it is generated.

However, in the ceramic filter described in WO 2015/083628, as a basic configuration, a pore blocking type filter that removes foreign matter by blocking foreign matter larger than the pore diameter by pores formed in the filter. Because of this, the pressure loss of the filter due to the fouling substances is inevitable.

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

In view of the above objects, as a result of earnest research, the present inventors are composed of a base material made of porous ceramic and particles of a metal oxide fixed on at least a part of the surface of the base material and the inner surface of communicating holes. A porous ceramic honeycomb structure having bulky partition walls, wherein the total pore volume having a pore diameter of 10 to 200 nm measured by mercury penetration method is 0.1% or more per apparent volume of the partition walls, The present invention was conceived based on the finding that the ability to adsorb dissolved organic matter (polysaccharides and the like) in water to be treated was extremely excellent.

That is, the adsorption member according to the present invention includes a plurality of axially extending flow paths partitioned by porous partition walls, and the water to be treated is allowed to pass through the plurality of flow paths to adsorb foreign substances in the water to be treated It consists 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 wall is
It has a communicating hole which connects between the flow paths,
A substrate made of porous ceramic,
It is comprised by the particle | grains of the metal oxide fixed to at least one part of the surface of the said base material, and the communicating hole inner surface,
It is characterized in that a 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.

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

In the adsorption member, the volume-based median pore diameter measured by mercury porosimetry (however, the volume-based median pore diameter is a total pore volume in a curve showing the relationship between the pore diameter of the partition wall and the cumulative pore volume) Is the pore diameter at a pore volume corresponding to 50% of), the median pore diameter on a surface area basis (however, the median pore diameter on a surface area basis, the relationship between the pore diameter of the partition and the cumulative pore surface area In the curve shown, the pore size at the pore surface area corresponding to 50% of the total pore surface area is preferably 50 to 5000 times).

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

The partition wall is
The porosity is 25 to 70%, and the volume-based median pore diameter measured by mercury porosimetry (however, the volume-based median pore diameter is a curve showing 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 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 wall is
A substrate made of porous cordierite,
It is preferable to be made of 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 manufacturing method of the adsorption member according to the present invention includes a plurality of axially extending flow paths partitioned by porous partition walls, and the water to be treated is allowed to pass through the plurality of flow paths to remove foreign substances in the water to be treated. A method of manufacturing a suction member to remove by suction
A clay containing a 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 flow paths partitioned by porous partition walls. The process to
Alternately forming plugging portions at flow path ends of the ceramic honeycomb structure;
Coating the partition walls of the ceramic honeycomb structure with metal oxide particles, and drying and firing the particles;
In the step of coating the particles of the metal oxide, drying and firing, the partition wall has communicating holes connecting between the flow channels, and all of the pores have a pore diameter of 10 to 200 nm measured by mercury intrusion method. It is characterized in that the pore volume is 0.1% or more per apparent volume of the partition wall.

The ceramic material is preferably a cordierite-forming material.

The metal oxide is preferably alumina.

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

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

Since the adsorption member of the present invention is excellent in adsorption capacity of foreign matter such as dissolved organic matter, it is suitable as a pretreatment of the treatment process by the separation membrane (reverse osmosis membrane etc.) in the water treatment system. By adding the treatment using the adsorption member of the present invention, the life of the reverse osmosis membrane can be extended, and the running cost for water treatment can be reduced.

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 wall 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 installation using the adsorption member of this invention. It is a schematic diagram which shows the adsorption | suction module incorporating the adsorption 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 comprises a plurality of axially extending flow channels 3 partitioned by porous partition walls 2; The porous ceramic honeycomb structure 4 is configured to allow the water to be treated to pass through the flow path 3 and to adsorb and remove foreign matter (dissolved organic matter etc.) in the water to be treated. The partition wall 2 has a communicating hole 5 connecting adjacent flow paths 3 and is fixed to at least a part of the base 6 made of porous ceramic, the surface 6 a of the base 6 and the inner surface 6 b of the communicating hole. Characterized in that the total pore volume of the metal oxide particles 7 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. Do.

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

The plurality of flow channels 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 water to be treated ) Or the other end (outgoing side of treated water) by alternately having plugged

portions

9a, 9b, the end face 10a on the inflow side of the to-be-treated water opens, and the opposite side of the treated water The first flow path 3a in which the end face 10b on the outflow side is plugged by the plugging portion 9a and the end face 10b on the outflow side of the treated water are opened, and the end face 10a on the inflow side on the other side is plugged And a second flow path 3b plugged by 9b. The first flow path 3a and the second flow path 3b are alternately arranged in the vertical and horizontal directions 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 adsorption member 1 will be described using FIGS. 2 and 3. The water to be treated that has flowed into the first flow path 3a opened to the end face 10a on the inflow side flows into the second flow path 3b through the fine communication holes 5 in the partition 2, and the end face 10b on the outflow side Are discharged to the outside of the adsorption 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 it passes through the fine communication holes 5 in the partition 2, the surface 6a of the base 6 of the partition 2 and the inner surface 6b of the communication hole Removing particles from the water to be treated by contacting the particles 7 of the metal oxide fixed on the metal particles, and the particles 7 of the metal oxide 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 the base material 6 made of porous ceramic, and the metal oxide particles 7 fixed to at least a part of the surface 6a of the base material 6 and the inner surface 6b of the communication hole. . The metal oxide particle 7 may be fixed to at least a part of the surface 6a of the base 6 and the inner surface 6b of the communication hole, and is preferably mainly fixed to the inside of the communication hole 6b. When the water to be treated passes through the adsorption member, the water to be treated is made of the metal oxide particles 7 fixed to the inner surface 6b of the communication hole rather than the metal oxide particles 7 fixed to the surface 6a of the substrate 6 Since the contact time is longer, by fixing a large number of metal oxide particles 7 on the inner surface 6b of the communication hole, foreign matter such as dissolved organic matter can be efficiently adsorbed and removed.

Preferably, the metal oxide particles 7 are laminated and fixed to the surface 6 a of the base 6 and the inner surface 6 b of the communication hole, as shown in FIG. 4. By having such a configuration, a large number of fine pores of 1 μm or less can be formed, and an adsorption member having a high specific surface area can be formed. Therefore, foreign matter such as dissolved organic matter in the water to be treated can be efficiently adsorbed and removed. That is, the partition wall 2 has a structure including relatively large pores forming the communication holes 5 and fine pores of 1 μm or less formed by the particles 7 of the metal oxide.

(a) Pore Structure The partition 2 has a total pore volume with a pore diameter of 10 to 200 nm measured by mercury porosimetry at 0.1% or more per apparent volume of the partition. This value is the ratio of "total pore volume having a pore diameter of 10 to 200 nm" 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 percentage of Pores having a pore diameter of 10 to 200 nm are mainly formed by the metal oxide particles 7 and largely contribute to the adsorption of foreign substances (dissolved organic matter etc.) in the water to be treated. If the total pore volume with a pore size of 10 to 200 nm measured by mercury porosimetry is less than 0.1% per apparent volume of the partition wall, are not enough pores having a pore size of 10 to 200 nm? Since many are present on the surface 6a of the base material 6 having a short contact time with the water to be treated, the effect of adsorbing and removing the dissolved organic matter becomes insufficient. The total pore volume having a pore diameter of 10 to 200 nm measured by mercury porosimetry is preferably 0.5% or more per apparent volume of the partition wall, and more preferably 1.0% or more. Here, since the apparent volume of the partition wall does not increase even if the metal oxide particles 7 are fixed to the inner surface 6b of the communication hole, the metal oxide particles 7 are fixed more to the inner surface 6b of the communication hole than the surface 6a of the substrate 6 In this case, the ratio of pore volume of 10 to 200 nm per apparent volume of partition wall becomes larger.

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

The mechanism by which metal oxides adsorb and remove dissolved organic matter such as polysaccharides will be briefly described below. For example, in the seawater desalination treatment, as described above, among organic substances dissolved in seawater, dissolved organic substances such as polysaccharides which selectively adhere to the reverse osmosis membrane and cause clogging are adsorbed and removed by pretreatment. Is desired. Most of these polysaccharides have an acid group such as a carboxyl group and so are negatively charged in seawater. On the other hand, metal oxides such as alumina have a hydroxyl group on the surface when water is adsorbed in water, and the hydroxyl group on the surface of alumina usually has an isoelectric point near pH = 9, so it is neutral The alumina surface is positively charged in seawater having a near pH. Therefore, alumina having a positively charged surface can adsorb and remove dissolved organic matter such as polysaccharides. Further, since many oxygen atoms exist on the metal oxide such as alumina, the dissolved organic matter is adsorbed to the metal oxide by the hydrogen bond between these oxygen atoms and the hydroxyl group possessed by the dissolved organic matter.

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

The upper limit of the isoelectric point of the metal oxide is preferably pH 10. In the adsorption member of the type that adsorbs and removes foreign matter in the water to be treated as in the present invention, if the adsorption performance decreases, the plus / minus of the surface charge is reversed during washing, and the adsorbed foreign matter is removed from the surface By peeling, the adsorption performance of the adsorption member can be regenerated. If a metal oxide having an isoelectric point of more than pH 10 is used, the surface charge can not be reversed to obtain sufficient repulsive force unless a stronger alkaline aqueous solution is used as a cleaning solution. When a strong alkali is used as the cleaning liquid, damage to the adsorption member and other members is increased. Therefore, in order to reduce the use of strong alkali as much as possible, the isoelectric point of the metal oxide is adjusted to pH 10 or less.

Examples of metal oxide particles include particles of α-alumina, γ-alumina, zinc oxide, etc. In particular, α-alumina and γ-alumina having excellent adsorption ability for dissolved organic matter are preferable, and in particular, the isoelectric point is around 9.1 Alpha alumina is most preferable because it is also excellent in corrosion resistance.

As a dissolved organic substance which exists in seawater, a polysaccharide is mentioned as a typical thing. For example, when a molecule having a molecular weight of 1,000,000 is considered as a polysaccharide, its molecular size (assumed to be a sphere with a density of 1 g / cm ³ ) is about 15 nm, and a molecule having a molecular weight of 5,000,000 is considered. The molecular size (assumed to be a sphere with a density of 1 g / cm ³ ) will be about 30 nm. Therefore, when many pores having a pore diameter of 10 to 200 nm formed by the metal oxide particles 7 exist, many surfaces on which these dissolved organic substances can be adsorbed exist, and the dissolved organic substances are efficiently adsorbed. It becomes possible to remove.

In the mercury intrusion method, pore distribution is obtained by immersing and pressing a bulkhead sample placed in vacuum into mercury, and determining the relationship between the pressure at the time of pressurization and the volume of mercury pressed into the pores of the sample. Is a way to In the mercury intrusion measurement, when the pressure is gradually increased, mercury is injected sequentially from the large diameter pore of the sample surface, and finally all the pores are filled with mercury. However, in the case of pores having a diameter of less than a few nm in practice, depending on the material, it may not be possible to accurately measure, therefore, in the present invention, measurement values obtained for pores of 6 nm or more are used The volume-based pore distribution (the relationship between the pore diameter of the partition wall and the cumulative pore volume) was determined. Therefore, the total pore volume is a value determined from the amount of mercury filled in the pores of 6 nm or more.

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

The volume-based median pore diameter D ₅₀ measured by mercury porosimetry is preferably 50 to 5000 times the surface-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 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 such as those formed by metal oxide particles are contained, the median pore diameter d _{50 on} a surface area basis is significantly smaller than the median pore diameter D _{50 on a} volume basis Shift to the side. Therefore, when many pores having a pore diameter of 10 to 200 nm, which are effective for adsorbing and removing the dissolved organic matter, are present, 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 decreases, and the effect of adsorbing and removing the dissolved organic matter is significantly reduced. When the value of D ₅₀ / d ₅₀ is more than 5000, many finer pores less than 10 nm exist, and the effect of adsorbing the dissolved organic matter is saturated. The value of D ₅₀ / d ₅₀ is more preferably 100 to 2500, and most preferably 150 to 1000.

As described above, the volume-based median pore diameter D ₅₀ is a value mainly reflecting the pores forming the communicating holes in the partition wall, and is preferably in the range of 1 to 50 μm, and is 1 to 30 μm. Is more preferable, 5 to 25 μm is more preferable, and 10 to 20 μm is most preferable. The volume-based median pore diameter D ₅₀ is preferably in the range of 0.005 to 0.15 times the thickness d of the partition walls. When the median pore diameter D _{50 on a} volume basis is less than 1 μm and / or less than 0.005 times the thickness d of the partition walls, the diameter of the communication holes becomes too small, so the resistance when passing water (pressure loss) In addition, clogging by components other than the adsorptive component becomes remarkable, 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 is more than 0.15 times the thickness d of the partition walls, the pores are too large, so the area of the inner surface of the through hole for fixing the metal oxide particles is It becomes smaller and the amount of metal oxide particles is reduced. Therefore, the ability to adsorb dissolved organic matter is reduced.

Since the adsorption member of the present invention removes dissolved organic matter by adsorption, even if the median pore diameter D _{50 on} a volume basis is in the range of 1 to 50 μm, it is dissolved in water with a size of 10 to 20 nm. It can remove organic matter. For this reason, unlike the pore blocking type filter (filtration membrane) which removes foreign substances by blocking foreign substances larger than the pore diameter by pores formed in the filter, small pressure loss and high removal performance of dissolved organic matter It is compatible.

(b) Porosity The porosity of the partition walls 2 is preferably 25 to 70%. The porosity of the partition wall 2 is determined by the pore volume of the communication hole 5 in the partition wall 2 of the substrate 6, the surface 6a of the substrate 6, the communication hole inner surface 6b, and the surface of the plugging

portions

9a and 9b. It is calculated from the sum of the volume of fine pores of 1 μm or less formed by coating the particles 7. Since the pore volume of the communication holes 5 is larger than the volume of fine pores of 1 μm or less formed in the coating, the porosity is almost determined by the pore volume of the communication holes 5. When the porosity of the partition wall 2 is less than 25%, many pores which do not form the communication holes 5 will be present, and the amount of the communication holes 5 will be reduced. When the porosity of the partition wall 2 is more than 70%, the mechanical strength of the partition wall 2 is reduced, and there is a possibility of breakage when a large pressure is applied to the treated water.

(c) Structure The thickness d of the partition 2 is preferably 0.1 to 2 mm, and the ratio d / w of the thickness d to the width w of the flow path formed by the partition 2 is expressed by the equation: 0.20 ≦ d / It is preferable to satisfy w ≦ 1.25. If the thickness of the partition 2 is less than 0.1 mm and / or 0.20> d / w, the mechanical strength of the partition 2 is reduced, and there is a possibility of breakage when a large pressure is applied to the water to be treated. At the same time, the length of the communication hole 5 can not 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 2 is more than 2 mm and / or d / w> 1.25, the pressure required to permeate the treated water becomes large (pressure loss increases), and time and energy for water treatment are increased. It takes The thickness d of the partition 2 and the width w of the flow path can be appropriately set by changing the dimension of the molding die.

Although not limited, it is preferable that the partition walls 2 be provided in a lattice shape or a mesh shape in the axial direction. Therefore, for example, when the partition walls 2 are provided in a lattice, the flow path 3 has a rectangular shape in the axial direction. In this case, the flow path 3 is preferably a square having a side of 0.5 to 8 mm in the axial direction. If one side of the flow path 3 is less than 0.5 mm, foreign matter other than the dissolved organic matter in the water to be treated may block the flow path 3a opened in the end face 10a on the inflow side of the ceramic honeycomb structure 4 Decreases. On the other hand, when one side of the flow path 3 is more than 8 mm, mechanical strength is insufficient unless the thickness of the partition 2 of the ceramic honeycomb structure 4 is sufficiently taken, and a large pressure is applied to the water to be treated. It is more likely to break. The shape of the flow path 3 is not limited to a square as shown in FIG. 1, and may be a shape that can be filled on a plane such as another quadrilateral, triangle, hexagon, combination of octagon and quadrilateral, etc. .

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

In the present invention, it is preferable that the base material of the partition walls be cordierite and the metal oxide particles be alumina. Cordierite is a substrate capable of easily forming pores, and contains alumina as a component, and therefore is effective in firmly fixing alumina.

(3) Plugging portion The plurality of channels 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 face on the inflow side of the treated water 10a is open, the first flow path 3a in which the end face 10b on the opposite side on the outflow side of treated water is plugged by the plugging portion 9a, and the end face 10b on the outflow side of treated water is open on the opposite side The end face 10a on the inflow side of the water to be treated has a second flow path 3b plugged by a plugging portion 9b. The first flow path 3a and the second flow path 3b are disposed adjacent to each other through the one partition wall 2, and the water to be treated flowing from the first flow path 3a is the partition wall 2 Treated water is configured to be discharged from the second flow passage 3b through the inner communication hole.

The plugged

portions

9a and 9b may be formed of the same material as the porous ceramic honeycomb structure 4 (the base 6 of the partition 2), an organic material, or a material which does not dissolve in treated water such as other inorganic materials. it can. In the case of forming the same material as the porous ceramic honeycomb structure 4, it can be formed by injecting a slurry made of a ceramic material into a predetermined end of the flow path and baking it. Further, examples of the organic material include materials such as polyimide, polyamide, polyimide amide, polyurethane, acrylic, epoxy, polypropylene, Teflon (registered trademark), and the other inorganic materials include ceramics other than the ceramic constituting the partition 2 ( Alumina, silica, magnesia, titania, zirconia, zircon, cordierite, spinel, aluminum titanate, lithium aluminum silicate etc.), glass and the like can be mentioned. Further, the formation of the plugging

portions

9a and 9b can be performed by using a known method.

The porosity of the plugged

portions

9 a and 9 b is preferably 0 to 40%, and is preferably smaller than the porosity of the partition 2. The axial length of the plugging

portions

9 a and 9 b is preferably thicker than the thickness of the partition 2. If the porosity of the material used for the plugging

portions

9a and 9b is more than 40% or higher 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 adsorption member without being adsorbed to the metal oxide particles 7.

[2] Manufacturing method of adsorption member The method of manufacturing the adsorption member of the present invention,
A clay containing a 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 flow paths partitioned by porous partition walls. The process to
Alternately forming plugging portions at flow path ends of the ceramic honeycomb structure;
And coating the particles of the metal oxide on the partition walls of the ceramic honeycomb structure, drying and firing.

(1) Formation of Porous Ceramic Structure The method of 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. Prepare powders such as kaolin, talc, silica, alumina, etc. Cordierite so that the mass ratio is SiO ₂ : 48-52%, Al ₂ O ₃ : 33-37%, and MgO: 12-15%. Preparation materials powder, adding additives such as pore former, binder such as methyl cellulose and hydroxypropyl methyl cellulose, if necessary, dispersant, surfactant, lubricant etc. after dry mixing well Add water and mix to make plasticized ceramic cups. Next, the clay is extruded using a molding die, cut and dried, and processing such as end face and outer periphery is performed as needed to obtain a dried body having a honeycomb structure. The dried product is fired (for example, at 1400 ° C.), and then a coating agent containing cordierite particles and colloidal silica is applied to the outer periphery and fired, and the cross section partitioned inside the outer peripheral wall 8 by the partition 2 is The cordierite porous ceramic honeycomb structure 4 is formed with a large number of rectangular channels 3. The formation of the outer peripheral wall 8 may be performed after the formation of plugging portions described later.

(2) Formation of plugged portions A binder and a dispersion medium (solvent) are added to the cordierized raw material powder used for producing the porous ceramic structure 4 to prepare a slurry for forming plugged portions. . A plurality of nozzles are used to alternately plug the slurry into the flow path 3 of the porous ceramic honeycomb structure 4 at the inflow side end of the water to be treated and the end side at the outflow side of the process water. The mixture is poured using a dispenser having the following, dried and fired to form the plugged

portions

9a and 9b.

Screen printing can be used to form the plugged

portions

9a and 9b, in addition to the dispenser. In the case of using the screen printing method, a printing mask having a predetermined position opened is disposed in alignment with the predetermined position of the ceramic honeycomb structure 4, and a high viscosity slurry is injected through the opening of the printing mask, and then The resultant is dried and fired to form plugging

portions

9a and 9b.

The plugged

portions

9a and 9b may be formed of the same material as the porous ceramic honeycomb structure 4 or may be formed of another ceramic material. In addition, 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, etc. And cordierite, spinel, aluminum titanate, lithium aluminum silicate, etc.) and the above-mentioned organic polymer material. For example, the plugging

portions

9a and 9b may be formed by pressing and fixing a plug prepared in advance with a material such as Teflon (registered trademark) with a rod or a syringe. In the case of using an organic polymer material, the temperature at which the plugging

portions

9 a and 9 b are formed is lower than the temperature at which the partition wall 2 is formed.

(3) Coating of metal oxide particles After formation of the plugging

portions

9a and 9b, the surface 6a and the communication hole inner surface 6b of the partition 2 of the porous ceramic honeycomb structure 4 and the plugging

portion

9a , 9b are coated with metal oxide particles 7. The coating of the metal oxide particles 7 can be carried out by the so-called washcoat method. A slurry containing metal oxide particles 7 (for example, α-alumina, γ-alumina) is drawn into the porous ceramic honeycomb structure 4 by suction, dried, and fired at 900 ° C. or less . An inorganic binder such as alumina sol can be added to the slurry. When firing is performed at more than 900 ° C., it is not preferable because fine crystals in the alumina sol and γ-alumina grow to form coarse particles, which may decrease the specific surface area. In order to obtain an adsorption member having fine pores of 1 μm or less formed by particles of metal oxide, the temperature of firing after coating of the particles of metal oxide is 900 ° C. or less.

As the metal oxide particles 7 to be coated, for example, alumina powder having an average particle diameter of 0.1 to 1 μm is preferably used. As such an alumina powder, one obtained by grinding alumina A-26 manufactured by Sumitomo Chemical Co., Ltd. may, for example, be mentioned. Further, as the binder, an alumina sol having an average particle diameter of 100 to 500 nm is preferable, and specifically, Cataloid AS series manufactured by JGC Co., Ltd. can be mentioned.

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 0.5 to 2 μm. More preferable. The total pore volume having fine pores of 1 μm or less formed by particles of metal oxide and having a pore size of 10 to 200 nm measured by mercury porosimetry is 0.1% or more per apparent volume of partition wall In order to obtain the adsorption member, the thickness of the metal oxide particles after firing is set to 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. In addition, in the case where the predetermined amount of metal oxide particles is not coated at one time, the wash coating method may be repeated plural times.

[3] Water Treatment Equipment The adsorption member 1 of the present invention is used, for example, in a water treatment equipment 100 as shown in the flow chart of 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 the water treated by the adsorption module 101, a water supply pump 103 for supplying water of the water storage tank 102, water supply The reverse osmosis membrane module 104 provided with the reverse osmosis membrane 105 which removes a to-be-separated substance from the water sent from the pump 103 is provided.

An adsorption module 101 incorporating the adsorption member 1 of the present invention is shown in FIG. The adsorption module 101 includes the adsorption member 1 of the present invention, and a filter support 110 supporting the treated liquid inflow side end surface and the treated water outflow side end surface of the adsorption member 1 via a holding member (not shown). It is comprised from the housing 111 (for example, the storage container made from an acryl) which accommodates the said adsorption | suction member 1 and the filter support body 110. The filter support 110 may be made of any material or material that allows the water to be treated to pass without resistance, has a strength not to be easily deformed by the pressure of the water to be treated, and has no eluted material in water. For example, resin mesh spacers such as polyethylene, polypropylene, polyethylene terephthalate and polystyrene, metal meshes such as stainless steel and titanium, or punching metals can be used.

The adsorption module 101 is a primary treatment that has been processed to remove dust and the like through a screen, to add a coagulant to a fine suspension such as sand, and to remove sedimentation, and to decompose organic matter using microorganisms. Water is supplied, and the 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 substances (dissolved organic matter etc.) in the water to be treated, passes through the water storage tank 102 and is pressurized by the water supply pump 103 while reverse osmosis It passes through the membrane 105, and is separated into permeate water from which organic matter and salts in treated water are removed and concentrated water in which organic matter and salts are concentrated. By adsorbing and removing foreign substances (dissolved organic matter and the like) in the primary treated water by the adsorbing member 1, the occurrence of clogging of the reverse osmosis membrane 105 can be prevented, and the exchange life of the reverse osmosis membrane 105 can be extended.

Since the adsorbing member 1 of the present invention functions as a pretreatment step of selectively adsorbing and removing organic substances and the like attached to the surface of the reverse osmosis membrane 105, such a water treatment facility 100 is desalinated by seawater, a semiconductor Water treatment using reverse osmosis membrane 105 such as pure water production used for precision electronic device manufacture, advanced treatment of drinking water, regeneration treatment of sewage and drainage (including not using microorganism treatment etc.), especially seawater Application to the process of desalination is possible.

The present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

(1) Preparation of Suction Member The suction members of the example (the present invention) and the comparative example were manufactured as follows.

Example 1
Preparation of powder of kaolin, talc, silica, aluminum hydroxide and alumina to make a cordierite raw material powder having a chemical composition of 50% by mass SiO ₂ , 36% by mass Al ₂ O ₃ and 14% by mass MgO I got To this cordierite-forming raw material powder are added methylcellulose and hydroxypropyl methylcellulose as a forming aid, and thermally expandable microcapsules as a pore former, and a specified amount of water is injected to carry out sufficient kneading to form a honeycomb structure. An extrudable clay was prepared.

The obtained clay was extruded using a molding die to prepare a honeycomb structure molded body, and after drying, the peripheral portion was removed and processed, and fired at 1400 ° C. for 24 hours. A plugging material made of cordierite-forming material so that the treated water inflow side end or the treated water outflow side end of the flow path is alternately plugged in the flow path of the ceramic honeycomb body after firing After filling the slurry, the plugging material slurry was dried and fired. A coating agent containing cordierite particles and colloidal silica is coated, dried and fired on the outer periphery of the ceramic honeycomb structure after forming the plugged portions to form an outer peripheral wall, and the outer diameter is 285 mm, the total length 330 A porous ceramic honeycomb structure of 0.3 mm in thickness, 0.3 mm in partition wall thickness and 1.6 mm in cell pitch was obtained.

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

Example 2
An adsorptive member of the present invention was produced in the same manner as in Example 1 except that alumina fine particles having α alumina as a source were used in place of the alumina fine particles having γ alumina as a source 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 diffraction.

Example 3
An adsorptive member of the present invention was produced in the same manner as in Example 1, except that the alumina fine particles derived from γ-alumina used in Example 1 were replaced with alumina fine particles derived from γ-alumina. 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 diffraction.

Comparative Example 1
To α-alumina powder, add methylcellulose and hydroxypropyl methylcellulose as a forming aid, and a spherical resin with a hollow structure and an average particle diameter of 10 to 45 μm as a pore forming material, inject water in a specified amount, and sufficiently knead To prepare a honeycomb structure which can be extruded into a honeycomb structure. The obtained clay was extruded using a molding die to prepare a honeycomb structure molded body, and after drying, the peripheral portion was removed and processed, and fired at 1400 ° C. for 24 hours. In the same way as in Example 1, cordierite is formed in the same manner as in Example 1 so that the treated water inflow side end or the treated water outflow side end of the flow passage is alternately plugged in the flow passage of the ceramic honeycomb body after firing. After filling the plugging material slurry made of the raw material, the plugging material slurry was dried and fired. A coating agent containing cordierite particles and colloidal silica is coated, dried and fired on the outer periphery of the ceramic honeycomb structure after forming the plugged portions to form an outer peripheral wall, and the outer diameter is 285 mm, the total length 330 A porous ceramic honeycomb structure made of alumina of mm, a partition wall thickness of 0.76 mm and a cell pitch of 2.66 mm was produced and used as an adsorption member. Coating of the metal oxide particles was not performed, and the thickness of the metal oxide particles was 0 μm.

Comparative example 2
An adsorption member made of porous cordierite was produced in the same manner as in Example 1 except that alumina was not coated on the surface of the partition wall and in the communicating hole. Coating of the metal oxide particles was not performed, and the thickness of the metal oxide particles was 0 μm.

Comparative example 3
The adsorption member obtained in Example 1 was further fired at 1400 ° C. for 24 hours to produce an adsorption member. The layer of alumina particles had a thickness in the range of 0.2 to 1 μm before firing at 1400 ° C. However, the surface of the ceramic honeycomb structure was 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 adsorption member was measured by mercury porosimetry. In the measurement by mercury intrusion method, a test piece (10 mm × 10 mm × 10 mm) cut from a porous ceramic honeycomb structure after coating of metal oxide particles is placed in a measurement cell of Micropores Autopore III. 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. The relationship between pore diameter and cumulative pore volume was determined from the relationship between pressure and volume. The pressure for introducing mercury is 0.5 psi (0.35 × 10 ^-3 kg / mm ² ), and the constants used to calculate the pore size from pressure use the values of contact angle = 130 ° and surface tension = 484 dyne / cm did.

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

Furthermore, from the volume-based pore distribution data, the relationship between the pore diameter of the partition wall and the cumulative pore surface area (data of the pore distribution based on surface area) is determined, and from the curve, it 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 measurement value of the total pore volume, assuming that the true specific gravity of cordierite is 2.52 g / cm ³ .

Note 1: Proportion of total pore volume with pore diameter of 10 to 200 nm in apparent volume of partition wall

(3) Evaluation of adsorption performance The adsorption performance of the adsorption members of Examples 1 to 3 and Comparative Examples 1 to 3 to dissolved organic matter was evaluated as follows. A solution to be treated is prepared by dissolving mannan, which is one of polysaccharides, in artificial seawater at a concentration of 6 mg / L, and is incorporated into an adsorption module as shown in FIG. 7 into a 25 mm diameter, 35 mm long adsorption member The liquid to be treated was supplied at a volumetric flow rate (SV) of 120 L / hr. The amount of mannan in the liquid to be treated at the inlet and outlet of the adsorption module (weight of carbon) measured with a TOC (total organic carbon) measuring instrument (TOC-L manufactured by Shimadzu Corporation), the amount of mannan adsorbed on the adsorption member The (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 evaluation conditions of the adsorption performance described above is 1.0 mg or more, it is possible to design a water treatment facility at practically acceptable cost and size. The results are shown in Table 3.

Note 1: Cumulative adsorption amount per adsorption member when treated liquid for 90 minutes

From Tables 2 and 3, the adsorption 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 partition wall have an adsorption amount of 1.0 mg or more in all It can be seen that the adsorption performance to dissolved organic matter is excellent. In Examples 2 and 3 in which the total pore volume with a pore diameter of 10 to 200 nm is 1.0% or more per apparent volume of partition wall, the adsorption amount is 1.5 mg or more, and the adsorption performance is further excellent Recognize.

(4) Water treatment using the adsorptive member of the present invention Kaolin, talc, silica, aluminum hydroxide and alumina powder are prepared to have a chemical composition of 50% by mass SiO ₂ , 36% by mass Al ₂ O ₃ and The cordierized raw material powder which becomes 14 mass% MgO was obtained. To this cordierite-forming raw material powder are added methylcellulose and hydroxypropyl methylcellulose as a forming aid, and thermally expandable microcapsules as a pore former, and a specified amount of water is injected to carry out sufficient kneading to form a honeycomb structure. An extrudable clay was prepared.

The obtained clay was extruded using a molding die to prepare a honeycomb structure molded body, and after drying, the peripheral portion was removed and processed, and fired at 1400 ° C. for 24 hours. A plugging made of cordierite-forming material so that the treated water inflow side end or the treated water outflow side end of the flow path is alternately plugged at the flow path end of the fired ceramic honeycomb body After filling the plug material slurry, the plugging material slurry was dried and fired. A coating agent containing cordierite particles and colloidal silica is coated, dried and fired on the outer periphery of the ceramic honeycomb structure after forming the plugged portions to form an outer peripheral wall, and the outer diameter is 267 mm, the total length 185 A porous ceramic honeycomb structure having a diameter of 0.8 mm and a cell pitch of 1.9 mm was obtained.

In the same manner as in Example 3, particles (alumina fine particles) of metal oxide were coated on the surface of the base of the partition wall of the obtained porous ceramic honeycomb structure and on the inner surface of the communicating hole to obtain the adsorption 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 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 adsorption member, actual seawater and the demonstration equipment which can add sewage to it were installed. The seawater added with the sewage is used as raw water, and the adsorption members obtained in inexpensive sand filtration (SF) are combined to perform pretreatment with (sand filtration (SF) + adsorption member), and the treated water becomes a reverse osmosis membrane module Strain A was prepared to be sent.

Water treatment system B (comparative example)
Pretreatment was performed with existing ultrafiltration membrane (UF) using seawater added with sewage as raw water, and strain B was produced in which the treated water was sent to the reverse osmosis membrane module.

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

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

By measuring the pressure rise of the reverse osmosis membrane after two weeks, the fouling suppression effect in the reverse osmosis membrane of each system was compared and evaluated. As a result, in the system B in which pretreatment with only the ultrafiltration membrane (UF) was performed without using the adsorption member of the present invention, the pressure increased by about 15%, and sand filtration (SF) was not performed without using the adsorption member of the present invention The pressure was increased by about 30% in the strain A ′ which was pretreated only. On the other hand, no increase in pressure was observed in the system A subjected to the pretreatment with the adsorption member of the present invention. Therefore, it has been confirmed that the pretreatment with the adsorption member of the present invention has a large fouling suppressing effect of the reverse osmosis membrane.

Claims

A porous ceramic honeycomb structure comprising: a plurality of axially extending flow channels partitioned by porous partition walls; and water to be treated is allowed to pass through the plurality of flow channels to adsorb and remove foreign substances in the water to be treated A suction member that
The flow path is alternately plugged on the treated water inflow side or the treated water outflow side,
The partition wall is
It has a communicating hole which connects between the flow paths,
A substrate made of porous ceramic,
It is comprised by the particle | grains of the metal oxide fixed to at least one part of the surface of the said base material, and the communicating hole inner surface,
An adsorptive member characterized in that a 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.
In the suction member according to claim 1,
An adsorptive member characterized in that 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,
An adsorptive member characterized in that a total pore volume having a pore diameter of 10 to 200 nm is 8% or less per apparent volume of the partition wall.
The adsorption member according to any one of claims 1 to 3
Volume-based median pore diameter measured by mercury porosimetry (however, the volume-based median pore diameter corresponds to 50% of the total pore volume in a curve showing the relationship between the pore diameter of the partition wall and the cumulative pore volume) The median pore diameter on the basis of surface area (but the median pore diameter on the basis of surface area is the total pore diameter in the curve showing the relationship between the pore diameter of the partition and the cumulative pore surface area). An adsorption member characterized in that the pore diameter is a pore surface area corresponding to 50% of the pore surface area).
In the suction member according to any one of claims 1 to 4,
When the thickness of the partition is d and the width of the flow path is w,
d is 0.1 to 2 mm,
Formula: 0.20 ≦ d / w ≦ 1.25
A suction member characterized by satisfying.
In the adsorption member according to any one of claims 1 to 5,
The partition wall is
The porosity is 25 to 70%, and the volume-based median pore diameter measured by mercury porosimetry (however, the volume-based median pore diameter is a curve showing the relationship between the pore diameter of the partition wall and the cumulative pore volume, An adsorption member characterized in that the pore diameter at a pore volume corresponding to 50% of the total pore volume is 1 to 50 μm, and 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 6,
An adsorbing member characterized in that the metal oxide particles are made of a material whose surface is positively charged when coming into contact with the water to be treated.
In the suction member according to claim 7,
An adsorbing member characterized in that the metal oxide particles are made of a material having an isoelectric point of pH 8-10.
In the adsorption member according to claim 7 or 8,
An adsorption member characterized in that the metal oxide is alumina.
The adsorption member according to any one of claims 1 to 9,
The partition wall is
A substrate made of porous cordierite,
An adsorption member comprising: particles of alumina coated on at least a part of the surface of the substrate and the inner surface of the communication hole.
The adsorption member according to claim 9 or 10
An adsorbing member characterized in that the alumina is α-alumina or γ-alumina.
In the suction member according to claim 11,
An adsorption member characterized in that the alumina is α-alumina.
A method of manufacturing an adsorption member including a plurality of axially extending flow channels partitioned by porous partition walls, and passing the water to be treated through the plurality of flow channels to adsorb and remove foreign substances in the water to be treated There,
A clay containing a 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 flow paths partitioned by porous partition walls. The process to
Alternately forming plugging portions at flow path ends of the ceramic honeycomb structure;
Coating the partition walls of the ceramic honeycomb structure with metal oxide particles, and drying and firing the particles;
In the step of coating the particles of the metal oxide, drying and firing, the partition wall has communicating holes connecting between the flow channels, and all of the pores have a pore diameter of 10 to 200 nm measured by mercury intrusion method. A pore volume makes 0.1% or more per apparent volume of the said partition, The manufacturing method of the adsorption member characterized by the above-mentioned.
In the manufacturing method of the adsorption member according to claim 13,
The method for manufacturing an adsorption member, wherein the ceramic raw material is a cordierite-forming raw material.
In the manufacturing method of the adsorption member according to claim 13 or 14,
The method for producing an adsorption member, wherein the metal oxide is alumina.
In the method of manufacturing a suction member according to any one of claims 13 to 15,
An alumina sol is used as an inorganic binder for coating of the particles of the metal oxide, and the manufacturing method of the adsorption member characterized by the above-mentioned.
In the method of manufacturing a suction member according to any one of claims 13 to 16,
The method for manufacturing an adsorption member, wherein the temperature of firing of the metal oxide particles is 900 ° C. or less.