JP5261784B2 - Water treatment filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter for water treatment which is excellent in removal performance of pollutants and turbidity components, and hardly causes clogging due to the turbidity components. <P>SOLUTION: The filter for water treatment having a laminated structure of a melt-blow nonwoven fabric and a porous material is provided. The filter for water treatment is laminated with the melt-blow nonwoven fabric and the porous material so that water to be treated passes through the melt-blow nonwoven fabric and then through the porous material. The melt-blow nonwoven fabric has a polystyrene particle collection efficiency of 90% or more when passing a polystyrene particle having a 0.3 &mu;m diameter at a wind velocity of 1.5 m/minute. The thickness of the melt-blow nonwoven fabric is 0.5-3.0 mm. The porous material is obtained by solidifying a mixture containing activated carbon and a resin. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a water treatment filter that removes contaminants (low-molecular organic compounds such as trihalomethane, chlorine and the like) and turbidity components contained in drinking water and the like.

  Drinking water such as tap water is required to contain free chlorine at a certain concentration or more for the purpose of sterilization. However, this free chlorine not only kills bacteria, but also reacts with natural organic compounds such as humic acid (humic substances) present in the raw water of tap water to produce carcinogenic low molecular weight organic compounds such as trihalomethanes. Produces chlorine compounds. Furthermore, drinking water also contains turbidity components that cause water turbidity.

  In order to remove pollutants (low molecular organic compounds such as trihalomethane, chlorine, etc.), a filter for water treatment using activated carbon is generally used.

  On the other hand, in order to remove the turbidity component, a hollow fiber membrane filter is generally used.

  The hollow fiber membrane filter has a feature that clogging hardly occurs and turbidity components are efficiently removed. However, when a hollow fiber membrane filter is used, the filter part generally has a two-layer structure of an activated carbon layer and a hollow fiber membrane, and there is a problem that the entire filter becomes large.

  When these activated carbon filters and hollow fiber membrane filters are used in combination, the apparatus becomes complicated and the cost increases. Accordingly, there is a need for a water treatment filter that simultaneously satisfies the performance of both removal of contaminants and removal of turbidity components. As such a water treatment filter, an activated carbon molded filter in which activated carbon particles are bonded and solidified with a heat-meltable polymer binder has been studied (Patent Documents 1 to 3).

  Patent Document 1 describes a water treatment filter formed of a porous body obtained by solidifying an activated carbon and an inorganic composite that adsorbs ions with a high molecular weight porous polymer. In this inorganic composite, particles having an average particle diameter of 5 to 40 μm and particles having an average particle diameter of more than 40 μm and 200 μm or less are mixed at a mass ratio of 1: 1 to 1: 7. The resulting mixture is described. Thus, it is described that a water treatment filter having good water purification performance can be obtained by limiting the particle diameter of the inorganic composite.

Patent Document 2 describes an activated carbon filter containing activated carbon and a polyethylene homopolymer or polyethylene copolymer. This polyethylene homopolymer or polyethylene copolymer has a melt flow index (MFI 190/15) of 1.2 to 10 g / min, a ratio of number average molecular weight to weight average molecular weight (Mw / Mn) of 3 to 30, It is described that the bulk density is 0.05 to 0.5 g / cm ³ and the particle diameter is 5 to 300 μm. Such polyethylene homopolymers and polyethylene copolymers have a relatively low melt flow index (low fluidity), so that they do not lose the inherent porosity of activated carbon, that is, the surface of activated carbon is coated with the polymer. It is described that the pores of the activated carbon are difficult to block.

  In Patent Document 3, a thin coating layer is formed on the surface of 100 parts by mass of activated carbon particles with a fine particle of 2 to 40 parts by mass of a polyolefin resin or polyamide resin having a center particle diameter of 1 to 30 μm, and then press molding. It is described that the activated carbon adsorbent obtained in this way can be used as a water purification material (filter).

  The activated carbon filter obtained by solidifying activated carbon particles described in Patent Documents 1 to 3 with a heat-meltable binder has a dense structure, that is, activated carbon particles, in order to improve the removal performance of contaminants such as trihalomethane dissolved in water. The structure needs to have a large specific surface area. The activated carbon filter having such a structure has high contact efficiency between water and activated carbon, and the contaminant removal performance is enhanced.

  However, the activated carbon filter having the above structure is likely to be clogged by the turbidity component when water containing the turbidity component is allowed to pass through.

Therefore, there is a need for a water treatment filter that is excellent in removing pollutants and turbidity components and is less likely to be clogged with turbidity components.
JP 2002-273417 A Special table 2002-525400 gazette Japanese Patent Publication No. 7-90168

  An object of the present invention is to provide a water treatment filter that is excellent in removing pollutants (particularly trihalomethane) and turbidity components and is less prone to clogging by turbidity components.

  The present invention provides a water treatment filter having a laminated structure of a melt blown nonwoven fabric and a porous body, and the water treatment filter passes the porous body after water to be treated passes through the melt blown nonwoven fabric. The melt blown nonwoven fabric and the porous body are laminated so as to pass through, and the melt blown nonwoven fabric passes polystyrene particles having a particle diameter of 0.3 μm through the melt blown nonwoven fabric at a wind speed of 1.5 m / min. And having a polystyrene particle collection efficiency of 90% or more, the thickness of the melt blown nonwoven fabric is 0.5 mm to 3.0 mm, and the porous body solidifies the mixture containing activated carbon and resin. Can be obtained.

  In one embodiment, the melt blown nonwoven fabric has a polystyrene particle collection efficiency of 98% or more when polystyrene particles having a particle diameter of 0.3 μm are passed through the melt blown nonwoven fabric at a wind speed of 3 m / min. .

  In one embodiment, the meltblown nonwoven fabric is electretized.

  In one embodiment, the electretization is performed by corona discharge, glow discharge, or arc discharge.

  In one embodiment, when water containing trihalomethane and a turbidity component is allowed to pass through, the accumulated water flow rate in which the trihalomethane is removed by 80% or more is 8000 L or more, and the water flow rate is 50% of the initial flow rate. The accumulated water flow rate at the time of becoming% is 6500L or more.

  ADVANTAGE OF THE INVENTION According to this invention, the filter for water treatment which is excellent in the removal performance of a pollutant (especially trihalomethane) and a turbidity component, and cannot be easily clogged with a turbidity component can be provided. Therefore, the replacement period of the water treatment filter can be lengthened.

  Hereinafter, the water treatment filter of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an example of the structure of the water treatment filter of the present invention. This water treatment filter 1 has a cylindrical shape having layers of a nonwoven fabric 8, a melt blown nonwoven fabric 2, a porous body 3, and a tubular body 4 in order from the outside to the inside, and for fixing them. It has an upper surface cap 5 and a lower surface cap 6. The inner hole of the cylindrical body 4 is a central hole 7, which functions as a water passage hole. In FIG. 1, the nonwoven fabric 8 is provided outside the melt blown nonwoven fabric 2, but the nonwoven fabric 8 is not necessarily provided.

  The melt blown nonwoven fabric 2 is mainly used for the purpose of removing solid content (turbidity component) in water. Examples of the raw material for the melt blown nonwoven fabric 2 include thermoplastic resins such as polyolefin (for example, polyethylene and polypropylene) and polystyrene. Among these, polyolefins such as polyethylene and polypropylene are preferable because the melting point is low, and the heat molding temperature can be set low, and in terms of operability and cost, production is advantageous. The thickness of the melt blown nonwoven fabric 2 is 0.5 mm to 3.0 mm, preferably 1.5 mm to 2.8 mm. When the thickness of the melt blown nonwoven fabric 2 is less than 0.5 mm, the turbidity component may not be efficiently removed. On the other hand, when the thickness of the melt blown nonwoven fabric 2 exceeds 3.0 mm, the nonwoven fabric is likely to be clogged.

  The melt blown nonwoven fabric 2 used for the water treatment filter of the present invention is 90% or more when polystyrene particles having a particle diameter of 0.3 μm are passed through the melt blown nonwoven fabric 2 at a wind speed of 1.5 m / min. Has polystyrene particle collection efficiency. “Polystyrene particles having a particle diameter of 0.3 μm” is assumed to be general atmospheric dust (size: 0.3 μm). The measurement of the polystyrene particle collection efficiency is performed according to JIS K 0901.

  Preferably, the melt blown nonwoven fabric 2 has a polystyrene particle collection efficiency of 98% or more when polystyrene particles having a particle diameter of 0.3 μm are passed through the melt blown nonwoven fabric 2 at a wind speed of 3 m / min. When the melt blown nonwoven fabric 2 having such polystyrene particle collection efficiency is used, it is possible to remove a finer solid content (turbidity component).

  Further, the melt blown nonwoven fabric 2 is preferably electretized. Electretization is performed by corona discharge, glow discharge, arc discharge, or the like.

  The electret melt blown nonwoven fabric 2 becomes activated (state in which radicals and the like are generated) because the energy of the nonwoven fabric surface is increased. Therefore, since more fine solid content is adsorbed, the polystyrene particle collection efficiency of the melt blown nonwoven fabric 2 is improved (that is, solid content (turbidity component) existing in water is easily adsorbed). Furthermore, since the surface of the nonwoven fabric is in a radical state, polar groups such as carbonyl groups produced by the reaction of carbon on the nonwoven fabric with oxygen in the air are introduced, improving wettability and improving the adsorption of turbidity components. To do.

  The porous body 3 used for the water treatment filter of the present invention can be obtained by solidifying a mixture containing activated carbon, a resin, and, if necessary, an ion exchanger. Solidification is performed by melting the resin contained in the mixture by heating and bonding the activated carbon particles or the activated carbon particles to the ion exchanger particles.

  Examples of the carbonaceous material of activated carbon contained in the porous body 3 include plants such as fruit shells (coconut shells, walnut shells, etc.), wood, sawdust, charcoal, fruit seeds, pulp production by-products, lignin, and molasses. Materials: Mineral materials such as peat, grass charcoal, lignite, lignite, lignite, anthracite, coke, coal tar, coal pitch, petroleum distillation residue; synthetic materials such as phenol resin, saran resin, acrylic resin; recycled fiber (For example, rayon). Among these, plant-based activated carbon is preferable and coconut shell activated carbon is more preferable in terms of adsorption performance and water purifier application.

  Conditions for carbonizing the carbonaceous material are not particularly limited. For example, in the case of a granular carbonaceous material, a condition such as processing at a temperature of 300 ° C. or higher while flowing a small amount of inert gas through a batch rotary kiln is adopted. can do.

  Activated carbon is obtained by a general method for producing activated carbon, and is not particularly limited. Usually, the activated carbon used in the present invention is produced by sufficiently carbonizing a carbonaceous material and then activating it by a method such as gas activation or drug activation. For example, examples of the gas used in the gas activation method include water vapor, carbon dioxide gas, oxygen, LPG combustion exhaust gas, or a mixed gas thereof. In consideration of safety and reactivity, a water vapor-containing gas (a gas containing 10 to 50% by volume of water vapor) is preferable.

  The activation temperature is usually 700 ° C to 1100 ° C, preferably 800 ° C to 1000 ° C. However, the activation temperature, time, and heating rate are not particularly limited, and vary depending on the type, shape, size, etc. of the carbonaceous material to be selected. Activated carbon obtained by activation can be used as it is, but in practice, it is preferable to remove the adhering component by acid washing, water washing or the like.

  The shape of the activated carbon is not particularly limited, and may be in any state such as powder, granule, or fiber. When powdered or granular activated carbon is used, activated carbon having an average particle diameter of 35 μm to 2.8 mm (350 mesh to 7 mesh) is preferable from the viewpoint of workability, contact efficiency with water, water passage resistance, and the like.

  When using fibrous activated carbon, it cuts into about 0.1 mm-3 mm from the point of a moldability, and is used. Furthermore, when using fibrous activated carbon, it is preferable to use activated carbon with an iodine adsorption amount of 1200 to 3000 mg / g from the viewpoint of the removal performance of free chlorine.

  The resin contained in the porous body 3 is used as a binder for fixing the activated carbon. Examples of such resins include thermoplastic resins and thermosetting resins.

  Thermoplastic resins include polyethylene, polypropylene, polystyrene, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene resin, polyethylene terephthalate, polybutylene terephthalate, ethylene acrylic resin, polymethyl methacrylate, nylon, mesophase pitch, hydrophilic resin (For example, polyvinyl alcohol resin, ethylene-vinyl alcohol resin, etc.).

  Examples of the thermosetting resin include furan resin and phenol resin.

  Examples of the ion exchanger that can be included in the porous body 3 include inorganic ion exchangers and ion exchange resins. When the temperature at the time of solidification of the mixture containing activated carbon, ion exchanger, and resin is 100 ° C. or higher, it is preferable to use an inorganic ion exchanger having heat resistance. Examples of the inorganic ion exchanger include zeolite (for example, aluminosilicate), titanosilicate, titanium dioxide, silicon dioxide, hydroxyapatite and the like. Among these, titanosilicate and aluminosilicate are particularly preferable because of their large ion exchange capacity and high selectivity for heavy metals. When titanosilicate is used, amorphous titanosilicate is more preferable. Furthermore, antibacterial properties are imparted by using an ion exchanger (for example, silver-carrying zeolite) that supports an antibacterial substance such as silver.

  The ratio of the activated carbon and resin contained in the porous body 3 is not particularly limited. When the mass of the activated carbon is 100 parts by mass, the resin is preferably contained in a proportion of 5 to 50 parts by mass, more preferably 6 to 20 parts by mass. When using an ion exchanger, activated carbon and an ion exchanger are contained preferably in a mass ratio of 100: 1 to 100: 50, more preferably 100: 2 to 100: 10.

  The cylindrical body 4 is provided so that the treated water does not contain solid content such as fragments of the porous body 3. The cylindrical body 4 is not particularly limited as long as it is a material that does not pass solid content such as fragments of the porous body 3 and allows only water to pass through. Examples of such a material include a nonwoven fabric, a plastic porous molded body, and a ceramic molded body.

  The upper surface cap 5 and the lower surface cap 6 are molded bodies made of synthetic resin or the like, and are used for fixing the melt blown nonwoven fabric 2, the porous body 3, and the cylindrical body 4 as shown in FIG. The upper surface cap 5 and the lower surface cap 6 are fixed to the upper and lower surfaces of the melt blown nonwoven fabric 2, the porous body 3, and the cylindrical body 4, and are preferably bonded and fixed. A hole is formed in the lower surface cap 6 according to the size of the diameter of the central hole 7 of the cylindrical body 4. The treated water is taken from this hole.

  In the water treatment filter 1 of the present invention, when water containing trihalomethane and a turbidity component is allowed to pass through, the accumulated water flow rate from which 80% or more of the trihalomethane has been removed is preferably 8000 L or more, more preferably 10,000 L or more. And the accumulated water flow rate when the flow rate of water reaches 50% of the initial flow rate is preferably 6500 L or more, more preferably 8000 L or more.

  The water treatment filter 1 shown in FIG. 1 has a structure in which a melt blown nonwoven fabric 2 and a porous body 3 are laminated in the lateral direction (that is, an out-in-flow type). The filter may have a structure in which the melt blown nonwoven fabric 2 and the porous body 3 are laminated in the vertical direction (that is, may be a downflow type).

  In the water treatment filter of the present invention, a nonwoven fabric 8 may be further laminated on the outer surface of the melt blown nonwoven fabric 2. This laminated nonwoven fabric 8 is not specifically limited, Arbitrary nonwoven fabrics are used.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to these Examples.

Example 1
A water treatment filter 1a was produced using the melt blown nonwoven fabric 2a, the porous body 3a, the cylindrical body 4a, the upper surface cap 5a, and the lower surface cap 6a.

The melt-blown nonwoven fabric 2a was a polypropylene melt-blown nonwoven fabric whose surface was corona discharge treated and electretized (fiber diameter 1.5 μm, basis weight 100 g / m ² , and thickness 0.8 mm). This melt blown non-woven fabric 2a was manufactured under the conditions of 0.2 mm orifice spacing, polypropylene discharge rate of 2 g / min / orifice per orifice, and a heating gas flow rate of 0.15 Nm ³ / min per 1 cm of the orifice row. According to the method of K 0901, when polystyrene particles having a particle size of 0.3 μm were passed at a wind speed of 1.5 m / min, they had a polystyrene particle collection efficiency of 92%.

  The porous body 3a was prepared as follows. 0.9 kg of finely powdered polyethylene having a melt index of 20 g / 10 min and 9.1 kg of granular activated carbon were put into a Henschel mixer, and stirred and mixed uniformly. As fine powder polyethylene, Frocene UF-20 (manufactured by Sumitomo Seika Co., Ltd.) was used. As the granular activated carbon, a 4: 1 mass ratio mixture of Kuraray Coal YP-100 and Kuraray Coal GW 60/150 (both manufactured by Kuraray Chemical Co., Ltd.) was used (particle diameter 50 μm to 250 μm).

Next, an aluminum mold having a bottomed cylindrical outer cylinder 11 as shown in FIG. 2 and an inner cylinder 12 made of a hollow cylinder concentrically with the outer cylinder, which is a thick cylinder A mold 10 capable of forming a shaped molded body was prepared, and this was uniformly filled with 320 g of a mixture of finely powdered polyethylene and granular activated carbon. The inner diameter (d ₁ ) of the outer cylinder 11 of this mold was 68 mm, the outer diameter (d ₂ ) of the inner cylinder 12 was 22 mm, and the depth (d ₃ ) of the outer cylinder 11 was 125 mm. After filling, it is heated and fused at 118 ° C. under a pressure of 7 kgf / cm ² for 150 minutes, allowed to cool for about 10 minutes, and has a cylindrical porous body 3a (outer diameter) having a center hole 7a penetrating from the top surface to the bottom surface 68 mm, center hole diameter 22 mm, and height 125 mm).

  A tubular body 4a made of a nonwoven fabric was bonded to the wall surface forming the central hole 7a of the porous body 3a, and a melt blown nonwoven fabric 2a was bonded to the outer surface of the porous body 3a. Next, the upper surface cap 5a and the lower surface cap 6a were adhered so as to fix the cylindrical body 4a, the porous body 3a, and the melt blown nonwoven fabric 2a, thereby obtaining a water treatment filter 1a.

  About the obtained filter 1a for water treatment, the turbidity component removal performance and the trihalomethane removal performance were evaluated by the following methods. These methods were respectively in accordance with turbidity component removal performance test (6.2.2) and volatile organic compound removal performance test (6.2.3) of JIS S 3201 (house water purifier test method). Is the method.

(Turbidity component removal performance test)
Test water was prepared by adding kaolin to raw water (tap water) to a concentration of 2 ppm. The test water is passed from the outside to the inside of the water treatment filter 1a under a pressure condition of 0.1 MPa (that is, the test water passes through the melt blown nonwoven fabric 2a and the porous body 3a in sequence), 4 . Flowed at an initial flow rate of 6 L / min. The integrated water flow when the water flow reached 50% of the initial flow rate was evaluated as turbidity component removal performance.

(Trihalomethane removal performance test)
Test water having a trihalomethane concentration of 100 ppb was allowed to flow at a flow rate of 4 L / min from the outside to the inside of the water treatment filter 1a under a pressure condition of 0.1 MPa. The integrated water flow rate when the trihalomethane removal rate was less than 80% was evaluated as the trihalomethane removal performance.

  Table 1 shows the results of the turbidity component removal performance test and the trihalomethane removal performance test.

(Example 2)
A water treatment filter 1b was produced in the same manner as in Example 1 except that the melt blown nonwoven fabric 2b was used instead of the melt blown nonwoven fabric 2a used in Example 1. As the melt blown nonwoven fabric 2b, a polypropylene melt blown nonwoven fabric whose surface was corona discharge treated and electretized was used (fiber diameter 1.5 μm, basis weight 100 g / m ² , and thickness 0.8 mm). This melt blown nonwoven fabric 2b is manufactured under conditions of an orifice interval of 0.2 mm, a polypropylene discharge speed of 0.5 g / min / orifice per orifice hole, and a heating gas flow rate of 0.2 Nm ³ / min per cm of the orifice row. According to the method of JIS K 0901, when polystyrene particles having a particle diameter of 0.3 μm were passed at a wind speed of 3 m / min, they had a 98% polystyrene particle collection efficiency.

  Using the obtained water treatment filter 1b, a turbidity component removal performance test and a trihalomethane removal performance test were performed in the same procedure as in Example 1. The results are shown in Table 1.

(Example 3)
A water treatment filter 1c was produced in the same manner as in Example 1 except that the melt blown nonwoven fabric 2c was used instead of the melt blown nonwoven fabric 2a used in Example 1. As the melt blown nonwoven fabric 2c, a non-electret polypropylene melt blown nonwoven fabric bonded with diatomaceous earth was used (fiber diameter 1.5 μm, basis weight 100 g / m ² , and thickness 0.8 mm). This melt blown nonwoven fabric 2c had a polystyrene particle collection efficiency of 98% when polystyrene particles having a particle diameter of 0.3 μm were passed at a wind speed of 3 m / min.

  Using the obtained water treatment filter 1c, a turbidity component removal performance test and a trihalomethane removal performance test were performed in the same procedure as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
A filter for water treatment was prepared in the same manner as in Example 1 except that the melt-blown nonwoven fabric 2a was not used in Example 1. Using the obtained water treatment filter, a turbidity component removal performance test and a trihalomethane removal performance test were performed in the same procedure as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
Instead of the melt blown nonwoven fabric 2a used in Example 1, a polypropylene melt blown nonwoven fabric (fiber diameter 1.5 μm, basis weight 100 g / m ² , and thickness 0.8 mm) that was not subjected to corona discharge treatment was used. A water treatment filter was prepared in the same manner as in Example 1. This meltblown nonwoven fabric had a polystyrene particle collection efficiency of 15% when polystyrene particles having a particle diameter of 0.3 μm were passed at a wind speed of 1.5 m / min.

  Using the obtained water treatment filter, a turbidity component removal performance test and a trihalomethane removal performance test were performed in the same procedure as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
Instead of the melt blown nonwoven fabric 2a used in Example 1, when polystyrene particles having a particle diameter of 0.3 μm are passed at a wind speed of 1.5 m / min, the polystyrene particle collection efficiency is 85%. A water treatment filter was prepared in the same manner as in Example 1 except that a melt blown nonwoven fabric made of polypropylene subjected to corona discharge treatment (fiber diameter 1.5 μm, basis weight 100 g / m ² , and thickness 0.8 mm) was used. Produced.

  As shown in Table 1, it can be seen that the water treatment filter of the present invention (Examples 1 to 3) has excellent turbidity component removal performance and trihalomethane removal performance. This is because the melt blown nonwoven fabric with high polystyrene particle collection efficiency used in the filter for water treatment of the present invention captures turbidity components (kaolin particles) and the porous body effectively removes trihalomethane. Therefore, it can be seen that a water treatment filter having excellent turbidity component removal performance and trihalomethane removal performance can be obtained.

  Furthermore, as is clear from comparison between Example 2 and Example 3, when an electret meltblown nonwoven fabric is used, fine solids in water are easily adsorbed. Therefore, since the porous body is less likely to be clogged, a water treatment filter having better turbidity component removal performance can be obtained.

  The filter for water treatment (Comparative Example 1) that does not use a melt blown nonwoven fabric has excellent trihalomethane removal performance. However, since the melt-blown nonwoven fabric that captures the turbidity component is not used, the porous body is immediately clogged. Therefore, a water treatment filter that does not use a meltblown nonwoven fabric has poor turbidity component removal performance.

  A filter for water treatment using a melt blown nonwoven fabric having a polystyrene particle collection efficiency of 90% or less (when polystyrene particles having a particle diameter of 0.3 μm are passed at a wind speed of 1.5 m / min) (Comparative Example 2 and 3) has excellent trihalomethane removal performance. However, since the polystyrene particle collection efficiency of the melt blown nonwoven fabric is low and the turbidity component cannot be sufficiently captured, the porous body is likely to be clogged. Therefore, a water treatment filter that does not use a meltblown nonwoven fabric has poor turbidity component removal performance.

  ADVANTAGE OF THE INVENTION According to this invention, the filter for water treatment which is excellent in the removal performance of a pollutant and a turbidity component, and cannot be easily clogged with a turbidity component can be provided. The water treatment filter of the present invention is used, for example, by being filled in a water purifier and connected to a water tap or the like. The water treatment filter of the present invention is useful because the replacement period of the water treatment filter can be extended.

It is sectional drawing which shows an example of the structure of the filter for water treatment of this invention. It is a figure which shows an example of the metal mold | die for forming the porous body used for the filter for water treatment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water treatment filter 2 Melt blown nonwoven fabric 3 Porous body 4 Cylinder 5 Upper surface cap 6 Lower surface cap 7 Center hole 8 Nonwoven fabric 10 Mold 11 Outer cylinder 12 Inner cylinder

Claims (5)

A tap water treatment filter having a laminated structure of a melt blown nonwoven fabric and a porous body,
The melt-blown nonwoven fabric and the porous body are laminated so that the water to be treated passes through the porous body after passing through the melt-blown nonwoven fabric,
The meltblown nonwoven fabric has a polystyrene particle collection efficiency of 98% or more when polystyrene particles having a particle diameter of 0.3 μm are passed through the meltblown nonwoven fabric at a wind speed of 3 m / min,
The meltblown nonwoven is electretized by corona discharge, glow discharge, or arc discharge,
The melt blown nonwoven fabric has a thickness of 0.5 mm to 3.0 mm, and the porous body is obtained by heat-sealing a mixture containing granular activated carbon having a particle diameter of 50 μm to 250 μm and a thermoplastic resin.
Filter for tap water treatment.   The filter for tap water treatment according to claim 1, which is used by being filled in a water purifier.   The filter for tap water treatment according to claim 1 or 2, wherein a raw material of the melt blown nonwoven fabric is polyethylene or polypropylene.   The tap water treatment filter according to any one of claims 1 to 3, which has a thick cylindrical shape. The tap water treatment filter according to claim 4 having an outer shape of 68 mm, a center hole diameter of 22 mm, and a height of 125 mm,
According to the turbidity component removal performance test (6.2.2) and the volatile organic compound removal performance test (6.2.3) of JIS S 3201, the test water added so that trihalomethane becomes 100 ppb was added to tap water. When the flow rate is 4 L / min from the outside to the inside of the water treatment filter under a pressure condition of 0.1 MPa, the integration at the time when the removal rate of the trihalomethane becomes less than 80% Test water having a water flow rate of 8000 L or more and added to tap water so that kaolin is 2 ppm is passed from the outside to the inside of the tap water treatment filter under a pressure condition of 0.1 MPa. A tap water treatment filter having an accumulated water flow of 7500 L or more when the water flow reaches 50% of the initial flow rate when flowing at an initial flow rate of 6 L / min.

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