JP2008055282A - Filtration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable removal of microorganisms, such as cryptosporidium, and fine particles which cannot be sufficiently removed by conventional filtration treatment, and suppression of clogging of both a membrane and a filter medium layer, thereby reducing backwashing frequency, backwashing time, and the amount of backwashing water and increasing their exchange life. <P>SOLUTION: A membrane 15 made of anisotropic porous material, such as metal and ceramics, and having an adjusted porous diameter of 0.1 to several 10 μm is arranged under a filter medium layer 3 made by accumulating sieved natural filter mediums, such as silica sand, granular activated carbon and anthracite, according to the particle diameter. Water to be treated flowing into a filter basin 2 flows through a route from the filter medium layer 3 to the membrane 15 to be filtered. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a filtration system used in a water purification plant or the like.

  In the water treatment plant, raw water is taken from water sources such as rivers and reservoirs, and suspended and colloidal substances are removed and bacteria are harmed by five unit processes of coagulation, flock formation, sedimentation, filtration and sterilization. It is supplied to customers as tap water.

  For a series of turbidity treatments by agglomeration, flock formation, precipitation, and filtration, a method using an aggregating agent is common, and an inorganic metal salt such as iron or aluminum is usually used as the aggregating agent. The effect of the flocculant is influenced by various physical and biochemical factors, and the optimum flocculation condition is based on a complex equilibrium determined by many factors. Cost.

  FIG. 20 is a flowchart showing a conventional turbidity treatment system for filtering treated water after aggregation and precipitation.

  In this figure, raw water is once stored in the landing well 100, and the amount of water sent to the water purification process is adjusted here. The raw water sent from the landing well 100 enters the agglomeration / sedimentation basin 101, where a large suspension, which is the majority of the turbidity in the raw water, is obtained by the procedure of coagulant injection → rapid stirring → slow stirring → precipitation. After being removed, it is sent to the filter basin 102. In the filtration basin 102, the filtered water separated by filtering the fine suspended matter that cannot be removed in the flocculation / sedimentation basin 101 is sent to the next water purification treatment step.

  At this time, the filtration basin 102 includes a slow filtration (filtration rate 3 to 6 m / day) and a rapid filtration (filtration rate 120 to 150 m / day). Today, the installation area is small and the turbidity is high. For this reason, rapid filtration is often used.

  Next, the rapid filtration basin used as the filtration basin 102 is demonstrated, referring the block diagram of FIG.

  The rapid filtration pond 131 includes a filter medium layer 103 on which “filter medium” made of natural silica sand that has been sieved is spread, a porous concrete layer 104 that prevents the filter medium from flowing out, a dispersed gravel layer 105 that supports them, and a perforated concrete plate And a supporting beam 107 that supports 106. Further, backwashing water is introduced into the catchment basin 108 formed in the lower part of the rapid filtration basin 131 to introduce backwash water necessary for backwashing the filter medium layer 103 (hereinafter referred to as backwashing or backwashing). A water introduction pipe 109 and an air introduction pipe 113 for introducing air are connected, and the amount of backwash water and the flow rate of air can be adjusted by valves 111 and 114. Further, a backwash drainage pipe 110 for discharging backwash drainage is connected above the filter medium layer 103, and the amount of backwash drainage can be adjusted by a valve.

  Then, when the water to be treated is introduced into the upper part of the rapid filtration pond 131, the suspended matter in the water to be treated enters the gaps in the sand while descending through the filter medium layer 103 due to gravity and flowing down through the filter medium. And removed from the water to be treated. The flow rate is about 8 to 10 cm per minute (filtration speed 120 to 150 m / day), and the filtered water passes through the porous concrete layer 104, the dispersed gravel layer 105, and the perforated concrete plate 106, and the water collecting rod 108. After being temporarily stored, it is sent to the next water purification process. In order to prevent clogging of the filter medium, the filter medium layer 103 uses “anthracite” having a large particle size and a small specific gravity in the upper part and silica sand having a small particle diameter and a large specific gravity in the lower part.

When clogging occurs, the backwashing water is introduced from the lower backwashing water introduction pipe 109 and the water flows from the bottom to the top, so that the clogging is removed from the filter medium layer 103. And drained from the backwash drainage pipe 110. The backwashing is composed of two stages. In the first stage, the filter medium of the filter medium layer 103 is made into a fluid state by backwash water, and the filter medium particles collide and friction with each other due to a local short circuit flow or a small vortex. And the shearing force of the water stream promote separation and separation of adhering turbidity. In the second stage, as the valve 112 is opened, the suspended matter separated from the filter medium and the membrane is discharged from the backwash drainage pipe 110 and sent to a wastewater treatment process (not shown). Further, in the air cleaning method, in combination with the backflow cleaning, air is blown from the air introduction pipe 113 provided on the lower side of the filter basin 102 to peel off the turbidity adhering to the filter medium. Either cleaning method is performed, and there are various methods such as blowing air and water at the same time, blowing air for several minutes and then introducing water, and the amount of air is 0.8 to 1.5 m ³ / ( min · m ² ) and the amount of water are adjusted by valves 111 and 114 so that the amount of water is 0.6 to 0.8 m ³ / (min · m ² ).

  As a technique for optimizing such a conventional turbidity treatment operation method, there is one described in JP-A-2002-192163 (Patent Document 1). On the other hand, according to the “Cryptosporidium Provisional Countermeasure Guidelines for Waterworks” issued by the Ministry of Health and Welfare (currently the Ministry of Health, Labor and Welfare) in October 1996, the turbidity at the outlet of the filtration basin is always grasped, and the turbidity at the outlet of the filtration basin is 0.1 It has been enacted to maintain the temperature below this level, and turbidity management at water treatment plants has become an important issue.

  Cryptosporidium is a parasitic protozoa that infects animals, exists outside the body in the form of oocysts, and is said to be 4-6 μm in size. Cryptosporidium oocyst removal rate is 97-99% in the case of normal treatment, and 99.7-99.9% even when coagulation sedimentation and sand filtration are used in combination. And all Cryptosporidium cannot be removed reliably.

  In particular, the rapid filtration basin 131, which is widely used as a filtration means because of its small installation area and high turbidity, is the final process of removing suspended substances in the water purification process of the water purification plant. Cryptosporidium However, it is an important final removal process. However, when the filtration flow rate changes suddenly during the transition from the filter media washing to the filtration process, or when the amount of treated water is changed, turbidity or Cryptosporidium flows out to the filtrate water side, or the washing wastewater is not drained sufficiently. , There is a risk of mixing into the filtered water after resumption of treatment.

  Against this background, research and development on microfiltration membranes and ultrafiltration membranes have advanced as an alternative to conventional turbidity treatment, and membrane filtration has begun to spread rapidly in water purification plants in Japan. Overseas, membrane filtration water treatment plants with a scale of several hundred thousand tons per day are already in operation.

  However, membrane filtration using microfiltration membranes and ultrafiltration membranes has the advantage of reliably removing turbid substances and obtaining good quality treated water, but it is the most popular material for microfiltration membranes and ultrafiltration membranes. Organic polymer compounds (cellulose acetate, polysulfone, polyethylene, polypropylene, polyacrylonitrile) membranes are subject to physical degradation such as consolidation and damage of the membrane over time, and chemical degradation due to hydrolysis and oxidation. The performance is degraded by external factors such as degradation of the membrane itself, such as biological deterioration that is utilized by microorganisms, and accumulation of fine particles and suspended substances on the membrane surface. For this reason, the lifetime is assumed to be 3 to 5 years, and the running cost is higher than the conventional water purification system due to the cost required for membrane replacement.

As a conventional technique for reducing the running cost, there is a technique described in Japanese Patent Laid-Open No. 2001-225057 (Patent Document 2). In this prior art, a flocculant is formed using a flocculant, and this is removed by sand filtration. Furthermore, it is a filtration system that reliably removes fine particles and suspended solids with a highly durable metal membrane filtration device.
JP 2002-192163 A JP 2001-225057 A

  However, the conventional turbidity treatment by the above-mentioned conventional aggregation, floc formation, precipitation, and filtration has the following problems.

[1] Residual micropathogenic protozoa such as Cryptosporidium in filtered water Micropathogenic protozoa such as Cryptosporidium that could not be removed even in the filtration basin, which is the final process of removing suspended substances, may remain in filtered water. is there. In particular, in rapid filtration ponds, when the flow rate of filtration changes suddenly from the washing of the filter medium to the filtration process or when the amount of treated water changes, turbidity or Cryptosporidium flows out to the filtered water side, or the filter medium is backwashed There is a risk that the drainage will not be drained sufficiently.

[2] Injection of a large amount of flocculant and increase in filtration loss head of the filter basin To increase the turbidity, if the amount of flocculant injected is increased, the flocculant that cannot be removed by the sedimentation basin flows into the filter basin. The filtration pond is clogged and the loss head of the filtration pond rises. On the other hand, microfiltration membranes and ultrafiltration membranes developed as an alternative to conventional turbidity treatment have the advantage of reliably removing turbid matter and obtaining good quality treated water, but have the following problems: It was.

[3] Increasing running costs Membranes of organic polymer compounds (cellulose acetate, polysulfone, polyethylene, polypropylene, polyacrylonitrile) that are most popular as materials for microfiltration membranes and ultrafiltration membranes, as the operating time elapses Physical degradation such as membrane consolidation or damage, chemical degradation due to hydrolysis, oxidation, etc., degradation of the membrane itself, such as biological degradation assimilated by microorganisms, Performance decreases due to external factors such as accumulation on the membrane surface. For this reason, the lifetime is assumed to be 3 to 5 years, and the running cost is higher than that of the conventional water purification system due to the cost required for membrane replacement. Moreover, in the combination of the conventional turbidity system described in JP-A-2001-225057 described above and a metal membrane filtration device, a non-woven cloth-like metal film obtained by laminating and sintering metal fibers is pleated. It was composed of a cylindrical element that was folded into two, and had the following problems.

[4] Reduction of permeation flux due to non-woven structure The metal film of non-woven structure has a structure that can be captured not only on the surface of the metal film but also inside the metal film. While there is a merit that particles and suspended substances can be trapped inside the membrane, fine particles and suspended substances that have entered the inside of the membrane cannot be removed by normal washing, and the permeation flux tends to decrease over time. There's a problem. Since the metal membrane by a cylindrical element has a small membrane filtration area effective with respect to the space filled with the metal membrane, there is a problem that the metal membrane filtration device becomes large and the installation space increases. There is a method of increasing the number of cylinders that are filled by narrowing the cylinder, but it is not appropriate to round the cylinder more thinly than necessary because the pore diameter of the membrane may increase.

  In view of the above circumstances, the present invention can ensure a high permeation flow rate and increase the flow rate of water to be treated, and reduce the treatment cost while reliably removing micropathogenic protozoa such as Cryptosporidium, It aims at providing the filtration system which can reduce the frequency | count of back washing | cleaning of a film | membrane, and can hold down operating cost low.

  In order to achieve the above object, the present invention provides a filtration system for filtering water to be treated using a filter basin, and a membrane using an anisotropic porous material is provided on the lower side of the filter basin, It is characterized in that the upper part of the filtration pond is filled with a filter medium for filtering suspended substances in the water to be treated.

  The membrane using the anisotropic porous material is characterized by having a plurality of stages having different pore diameters.

  Furthermore, a backwash drainage discharge pipe is connected to the upper side of the membrane of the filtration basin, and the backwash drainage discharged when the membrane is backwashed is discharged from the backwash drainage discharge pipe.

  Furthermore, a backwash water introduction pipe is connected to the upper side of the membrane of the filtration basin, and the backwash water is introduced into the filtration basin through the backwash water introduction pipe to wash the filter medium. It is said.

  Further, a part or all of the backwash water for the membrane is utilized as backwash water for the filter medium, and the membrane and the filter medium are backwashed simultaneously.

  Further, the cleaning of the membrane and the cleaning of the filter medium are respectively performed with different water amounts or backwashing cycles.

Furthermore, the amount of backwash water of the membrane is 0.1 to 0.5 m ³ / (min · m ² ).

Furthermore, the total amount of the backwash water amount of the membrane and the backwash water amount of the filter medium is adjusted to be 0.6 to 0.8 m ³ / (min · m ² ).

  Further, the filter medium is supported by a structure made of the membrane.

  Furthermore, the membrane is provided in a catchment basin below the filtration pond.

  Furthermore, in the filtration system for filtering the water to be treated using the filtration pond, the pore diameter is sequentially increased toward the upper side of the plurality of membranes constituted by the plurality of anisotropic porous materials having different pore diameters. It piles up so that it may become large, and it has arranged at the lower part of the above-mentioned filtration pond.

  Furthermore, the backwash water amount or backwash cycle of each membrane is changed for each membrane.

  Furthermore, the filtration rate of the filtration basin is adjusted to 1 to 1000 m / day, preferably 1 to 200 m / day.

  Furthermore, each of the membranes is back-washed at a permeation rate of 1 to 1000 m / day.

  Furthermore, an ultraviolet irradiation facility is provided below the film.

  Furthermore, an ultraviolet irradiation facility is provided on the upper part of the film.

  Furthermore, a unit structure is provided on the lower side of the filtration basin, and the membrane is disposed in the unit structure in a replaceable manner.

  In addition, a membrane using anisotropic porous material is provided on the lower side of the existing rapid filtration basin or slow filtration basin, and the upper side is filled with a filter medium for filtering suspended substances in the treated water. It is said.

  Furthermore, the filter medium includes any one of sieved natural silica sand, anthracite, and granular activated carbon.

  Furthermore, the pore diameter of the membrane is in the range of 0.1 μm or more and less than 10 μm, preferably 4 μm or less.

  According to the present invention, it is possible to ensure a high permeation flow rate and increase the flow rate of water to be treated, and to reliably remove micropathogenic protozoa such as Cryptosporidium while reducing the treatment cost, and to reverse the membrane. The number of washings can be reduced, and the operating cost can be kept low.

<Anisotropic porous material>
First, the anisotropic porous material developed by the present inventors will be described.

  In the filtration device using a metal film, the problem described in the background art section occurs. For this reason, the membrane filtration apparatus using the ceramic membrane which can form a fine pore diameter compared with a metal membrane and was excellent in backwashing property can be considered. However, since the ceramic film is basically a porous body in which fine particles are sintered in the form of a network, it has a structure that captures not only the surface of the film but also the inside as well as the metal film described above. There is a problem that it is difficult to wash the suspended solids and the permeation flux tends to decrease with the passage of operating time. In addition, because of the structure in which the pores form a complex network, the pressure loss is relatively large even in the initial characteristics.

  Therefore, in view of the above, the present inventors can perform a large amount of separation processing with high accuracy in a fluid filter, reduce the decrease in permeation flux, and improve the cleanability as follows (1) to (1) It came to develop the anisotropic porous material shown to 7).

(See Japanese Patent Application No. 2005-322629, unpublished).

  (1) It contains a plurality of pores, each of the pores has an anisotropic shape capable of defining a major axis and a minor axis, and the plurality of pores are arranged in a direction. Anisotropic porous material.

  (2) An anisotropic porous material, wherein the ratio of the major axis / minor axis length of each pore is 10 or more.

  (3) An anisotropic porous material characterized in that the short axis length of the plurality of pores is 0.001 to 500 μm.

  (4) The anisotropic porous material, wherein the plurality of pores are classified into one or more orientation groups whose major axis direction is included within a solid angle range of ± 10 degrees.

  (5) An anisotropic porous material, wherein at least some of the plurality of pores belonging to the same orientation group are through-pores.

  (6) An anisotropic porous material characterized in that the variation in the length of the short axis of the plurality of pores is ± 15% or less in the same orientation group.

  (7) An anisotropic porous material having a through porosity of 70% or more in the same orientation group.

  Hereinafter, the anisotropic porous material used in the membrane module of the present invention will be described in detail with reference to FIGS.

  First, the concept of the anisotropic porous material according to the present invention will be described with reference to FIG. The anisotropic porous material contains a plurality of pores, which have an anisotropic shape that can define a major axis and a minor axis, such as the pores 51 and 52 shown in FIG. . When the gaps between the arbitrary reference direction and the major axis are displayed as the inclination θ for the pores 51 and 52, the inclination θ has a tendency to be distributed in the directionality, that is, in a specific range. On the other hand, a material having no directionality in the pores is an isotropic porous material.

<< First example, part 1 >>
FIG. 13 is a schematic view showing the structure of the anisotropic porous material of the first example. As shown in FIG. 13, the anisotropic porous material 53 of the first example includes a plurality of elliptic spherical pores 52 shown in FIG. 12. The pores 52 included in the anisotropic porous material 53 shown in FIG. 13 are closed pores in which the entire pores are mainly contained in the material.

  Here, the ratio (aspect ratio) a / b of the major axis length a and minor axis length b of the pores 52 is preferably 10 or more. In the case of mainly composed of closed pores, the source of developing directional characteristics is due to the anisotropic form of closed pores. When the aspect ratio is less than 10, even if there is directionality in the arrangement between the pores, the characteristics as an isotropic porous material are not sufficiently exhibited because the characteristics are almost isotropic as a whole.

  Further, if the major axis direction of each pore is included in the range of the solid angle Ω, the solid angle Ω is preferably in the range of ± 10 degrees. In the case of mainly composed of closed pores, even if each closed pore has a high aspect ratio, if the directionality varies more than ± 10 degrees, it exhibits characteristics close to isotropic as a whole. The characteristics as a quality material are not fully exhibited.

  In addition, the short axis length b of each pore is preferably 0.001 to 500 μm. When the thickness is less than 0.001 μm, the shape is controlled on the order of the distance between atoms and molecules, and it is difficult to realize the structure of the anisotropic porous material of the present invention as a practical material. When it is larger than 500 μm, it is in a category that can be manufactured by existing machining such as drilling. This is not included in the concept of the anisotropic porous material of the present invention.

  Moreover, it is preferable that the variation of the short axis length b of each pore is ± 15% or less. In the case of mainly composed of closed pores, if the diameter of each closed pore is larger than ± 15%, the characteristic directivity as a whole becomes weaker and the characteristics are closer to isotropic. The characteristics as a material are not fully exhibited.

<< First example, part 2 >>
FIG. 14 shows a modification of the first example. The anisotropic porous material 54 of the modification of the first example contains a plurality of pores 51 having an anisotropic shape shown in FIG. The long axis of each pore is arranged in one direction.

  Also in the anisotropic porous material 54 shown in FIG. 14, the aspect ratio of each pore is 10 or more and the direction of the major axis of each pore is the same as the anisotropic porous material 53 shown in FIG. 13. It is included within a solid angle range of ± 10 degrees, the short axis length b of each pore is 0.001 to 500 μm, and the variation of the short axis length b of each pore is ± 15% or less. It is preferable. The reason for selecting these numerical values is also the same as described above.

<< Second example >>
FIG. 15 is a schematic view showing the structure of the anisotropic porous material of the second example. As shown in FIG. 15, the anisotropic porous material 55 of the second example contains a plurality of pores 52a and 52b. The pores contained in the anisotropic porous material 55 are mainly closed pores. The pores 52a constitute a first orientation group whose major axis has directionality with respect to the direction A, and the pores 52b have a second orientation group whose major axis has directionality with respect to the direction B different from the direction A. Configure.

  Here, similarly to the first example, the aspect ratio of the pores 52a and 52b is 10 or more, and the short axis length b of each pore is preferably 0.001 to 500 μm. The reason for selecting these numerical values is also the same as in the first example.

  If the direction of the major axis of each pore of the first orientation group is included in the range of the solid angle ΩA, the solid angle ΩA is preferably in the range of ± 10 degrees. Further, if the major axis direction of each pore of the second orientation group is included in the range of the solid angle ΩB, the solid angle ΩB is preferably in the range of ± 10 degrees. If the directionality varies more than ± 10 degrees, the characteristic as an anisotropic porous material is not sufficiently exhibited because the characteristics as a whole are nearly isotropic.

  Further, in the same orientation group, the variation of the short axis length b of each pore is preferably ± 15% or less. If the minor axis length b varies more than ± 15%, the characteristic directivity as a whole will be weakened and the characteristics will be closer to isotropic. Not.

<Third example>
FIG. 16 is a schematic view showing the structure of the anisotropic porous material of the third example. As shown in FIG. 16, the anisotropic porous material 56 of the third example has a plurality of through pores 57. Through-holes are pores that are open at the surface of the material at both ends. The anisotropic porous material 56 of the third example has a form in which the anisotropic porous material of the first example shown in FIG. 13 is cut out in two planes perpendicular to the major axis direction of the pores and parallel to each other. Yes.

  Here, the aspect ratio of the through-hole 57 is preferably 10 or more. When the aspect ratio is 10 or more, an excellent film material with a well-balanced strength characteristic suitable for filtering and the like can be obtained.

  Moreover, it is preferable that the direction of the long axis of each through-hole is included in a solid angle range of ± 10 degrees. If the directionality varies more than ± 10 degrees, characteristic characteristics such as pressure loss in filtering and the like deteriorate.

  Moreover, it is preferable that the length of the short axis of each through-hole is 0.001-500 micrometers. When the thickness is less than 0.001 μm, the shape is controlled on the order of the distance between atoms and molecules, and it is difficult to realize the structure of the anisotropic porous material of the present invention as a practical material. When it is larger than 500 μm, it is in a category that can be manufactured by existing machining such as drilling.

This is not included in the concept of the anisotropic porous material of the present invention.

  Further, the variation in the length of the short axis of each through-hole is preferably ± 15% or less. If the length of the short axis is more than ± 15%, the characteristic characteristics deteriorate, for example, the separation accuracy in filtering or the like is lowered.

  Moreover, it is preferable that the ratio (through-porosity) of the through-hole in all the pores which the anisotropic porous material 56 has is 70% or more. When the through-porosity is less than 70%, the permeate flow rate in filtering or the like is lowered, and the influence of pores other than the through-holes (open pores and closed pores) becomes obvious. Specifically, there is an influence such as a decrease in detergency in filtering and a decrease in film strength. Here, the open pores are pores that are open at the material surface only at one end.

  FIG. 17 is a schematic view showing a modification of the third example. As shown in FIG. 17, the anisotropic porous material 58 of the modified example of the third example has a plurality of through-holes 59, and the through-holes 59 correspond to the upper surface and the lower surface of the anisotropic porous material 58. It is formed in a non-vertical direction. The anisotropic porous material 58 of the modified example of the third example is different from the anisotropic porous material of the first example shown in FIG. 15 in parallel to each other at an angle other than perpendicular to the major axis direction of the pores. It has a form cut out on one side.

<< 4th example >>
FIG. 18 is a schematic view showing the structure of the anisotropic porous material of the fourth example. As shown in FIG. 18, the anisotropic porous material 60 of the fourth example has a plurality of through-holes 61a and 61b. The anisotropic porous material 60 of the fourth example has a form in which the anisotropic porous material of the second example shown in FIG. 15 is cut out from two parallel surfaces. The through-hole 61a constitutes a first alignment group, and the through-hole 61b constitutes a second alignment group.

  Here, as in the third example, the aspect ratio of the through-holes 61a and 61b is 10 or more, and the length b of the short axis of each pore is 0.001 to 500 μm. The through porosity is preferably 70% or more. The reason for selecting these numerical values is also the same as in the third example.

  Further, in the same orientation group, the direction of the long axis of each through-hole is preferably included in a solid angle range of ± 10 degrees. If the directionality varies more than ± 10 degrees, characteristic characteristics such as pressure loss in filtering and the like deteriorate. Moreover, in the same orientation group, the variation in the length of the short axis of each through-hole is preferably ± 15% or less. If the length of the short axis is more than ± 15%, the characteristic characteristics deteriorate, for example, the separation accuracy in filtering or the like is lowered.

  FIG. 19 is a schematic view showing a modification of the fourth example. As shown in FIG. 19, the anisotropic porous material 63 of the modification of the fourth example has a plurality of through-holes 64a and 64b, respectively, and the anisotropic porous material of the first example shown in FIG. What was cut out by two parallel surfaces has a form in which the direction of the through pores is shifted by 90 ° for each layer.

  Each of the above-described anisotropic porous materials is different from existing porous materials such as general porous materials or porous membranes used for the purpose of water purification described above, The pores with a short axis and large aspect ratio are arranged with directionality. For this reason, when the one-dimensional anisotropic porous material of the first and third examples is used for a fluid filter, fine particles and suspended substances are captured on the surface of the filter, so that a large amount of separation processing can be performed with high accuracy. It is possible to reduce the decrease in the permeation flux and improve the cleanability of the filter.

  Further, when the two-dimensional anisotropic porous material of the second and fourth examples is used as a heat exchange material, energy loss due to fluid resistance is greatly reduced, so that the heat exchange efficiency per volume can be improved.

  Although the applications of each of the anisotropic porous materials described above are various, the one-dimensional anisotropic porous materials of the first and third examples can perform a large amount of separation processing with high accuracy and provide a high permeation flux. Examples include various filters having excellent characteristics such as ensuring and excellent cleaning properties.

  Further, in the two-dimensional anisotropic porous material of the second and fourth examples, a heat exchanger in which heat exchange efficiency per volume is remarkably excellent and energy loss due to fluid resistance is greatly reduced can be mentioned. .

  The method for producing an anisotropic porous material of the present invention includes a method using a template for forming pores or through-holes, a method of forming pores or through-holes by transfer, and stretching the original structure of the pores or through-holes. It is possible to adopt a method of forming pores or through-holes by crystal structure growth, and a method of forming pores or through-holes by a gas phase synthesis method.

  In each of the above-described embodiments, the anisotropic porous material in which the pores are composed of one or two orientation groups is shown, but the number of orientation groups to be classified is not limited to this.

<Description of Embodiment>
Hereinafter, embodiments of a filtration system according to the present invention will be described with reference to the drawings. In the filtration system described below, any one of the anisotropic porous materials 53, 54, 55, 56, 58, 60, and 63 described above is used for the filtration membrane constituting the membrane module.

First Embodiment (corresponding to claims 1, 18, 19 and 20)
FIG. 1 is a block diagram showing an embodiment of a filtration system according to the present invention.

[Constitution]
The filtration system 1 shown in this figure is composed of any one of anisotropic porous materials 53, 54, 55, 56, 58, 60, 63 made of metal or ceramic, and is arranged in the filtration pond 2. The membrane 15 is combined with a filter medium layer 3 in which filter media such as sieved natural “silica sand”, “granular activated carbon”, “anthracite” and the like are laminated according to particle size.

  Specifically, it is composed of a filter medium layer 3 laid with “filter medium” made of natural silica sand that has been sieved, and an anisotropic porous material made of metal or ceramic having pores of 0.1 μm to several tens of μm. A membrane 15 disposed below the filter medium layer 3, a porous concrete layer 4 disposed below the membrane 15, a dispersed gravel layer 5 disposed below the porous concrete layer 4, and a dispersed gravel. It consists of a perforated concrete plate 6 disposed below the layer 5 and a support beam 7 that supports the perforated concrete plate 6.

  In addition, the drainage basin 8 formed in the lower part of the filtration basin 2 includes a backwash water introduction pipe 9 for introducing the backwash water and air for washing the filter medium layer 3 and the membrane 15, an air introduction pipe 13, While the valves 11 and 14 are connected, a backwash drainage discharge pipe 10 for discharging backwash drainage and a valve 12 are connected above the filter medium layer 3. When the main purpose is to remove Cryptosporidium, the size of Cryptosporidium is 4 to 6 μm. Therefore, in order to ensure the removal, the pore diameter of the membrane 15 is preferably less than 4 μm.

  At this time, when a new filtration system 1 is to be made, a membrane 15 using an anisotropic porous material made of metal or ceramic is laid on the lower part of the rapid filtration pond, and then a natural filter is directly formed on the membrane 15. A filter medium layer 3 in which filter media such as “silica sand”, “granular activated carbon”, and “anthracite” are laminated according to particle size is spread.

  Moreover, when remodeling the existing rapid filtration basin to the filtration system 1 of the present invention, the porous concrete layer 4 and the dispersed gravel layer 5 for preventing the flow of the existing filter medium may be left. Although the membrane 15 is laid between the concrete layer 4 and the filter medium layer 3, it is preferable that the porous concrete layer 4 and the dispersed gravel layer 5 are not provided even when a filter basin is newly constructed or an existing filter basin is modified. .

[Action]
In the filtration system 1, when the water to be treated is introduced from above the filtration pond 2, the suspended matter in the water to be treated is sanded while descending the filter medium layer 3 by gravity and flowing down the filter medium. It will be removed from the water to be treated. Next, a substance larger than the pores is trapped on the membrane surface by the sieving action of the membrane 15 using the anisotropic porous material having pores of 0.1 μm to several tens of μm. The filtered water that has passed through the pores passes through the porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete plate 6, and is stored in the catchment 8. At this time, the speed at which the water to be treated flows down the filter medium layer 3 and the membrane 15 using the anisotropic porous material is about 8 to 10 cm per minute (filtration speed 120 to 150 m / day). And the filtered water which stored the water collection tank 8 is sent to the following water-purification process not shown.

  In order to prevent clogging of the filter medium, the filter medium layer 3 uses “anthracite” having a large particle diameter and a small specific gravity in the upper part, and silica sand having a small particle diameter and a large specific gravity in the lower part. Further, when clogging occurs in the membrane 15 using the anisotropic porous material or the filter medium layer 3, the backwash water is introduced from the backwash water introduction pipe 9 at the bottom, and the water flows from the bottom to the top. As a result, the clogged material is removed from the membrane 15 and the filter medium layer 3 and drained from the backwash drainage pipe 10.

  The backwashing is composed of two stages. In the first stage, the filter medium in the filter medium layer 3 is made into a fluid state by backwash water, and the filter medium particles collide and friction with each other due to a local short circuit flow or small vortex. And the shearing force of the water stream promote separation of adhering turbidity and separate. In the second stage, as the valve 12 is opened, the suspended matter separated from the filter medium and the membrane is discharged from the backwash drainage pipe 10 and sent to a separate wastewater treatment process.

In the air cleaning method, air is blown from the air introduction pipe 13 at the lower part of the filter basin 2 together with the backflow cleaning, and the suspended matter adhering to the filter medium is peeled off. In the backwashing, any cleaning method is performed. There are various methods such as blowing air and water at the same time, or blowing air for several minutes and then introducing water, and the amount of air is 0.8-1. The valves 11 and 14 are adjusted so that the amount of water is 5 m ³ / (min · m ² ) and the amount of water is 0.6 to 0.8 m ³ / (min · m ² ).

[effect]
As described above, in the first embodiment, the membrane 15 using the anisotropic porous material has the pores in the same direction as the permeation direction of the feed water, and the ratio of the space occupied in the material (space ratio). Since it is large, the filtration resistance of the supplied water is reduced, and the permeation flow rate can be increased as compared with the microfiltration membrane and the ultrafiltration membrane that are usually used for water supply. That is, when the membrane 15 is introduced into the conventional rapid filtration pond, the filter medium layer 3 must flow down at a filtration speed of 120 to 150 m / day, but the membrane 15 also flows at the same flow rate. However, with conventional organic polymer microfiltration membranes, ultrafiltration membranes, non-woven fabric-like ceramic membranes, and metal membranes, depending on the pressure applied (in the case of filtration pond 2, loss head), The treated water can flow only at a filtration rate of m / day. On the other hand, in the membrane 15 made of an anisotropic porous material, the water to be treated can flow up to several hundred m / day (effect of claim 1).

  Here, the difference between the conventional film and the film 15 made of an anisotropic porous material will be described with reference to FIGS. FIG. 2A is a structural diagram of a conventional organic polymer material based microfiltration membrane or ultrafiltration membrane module. The filtration membrane 201 made of an organic polymer material has the lowest filtration rate, and the structural strength is weak and no pressure is applied. However, the filtration rate and strength can be improved by processing the organic polymer material-based filter membrane 201 as shown in FIG. 2A into a fiber having an outer diameter of several millimeters. The filtration speed and strength are the best compared to other filtration membranes. However, when a membrane system is introduced into a filtration basin, it must have a flat plate structure, and an organic polymer material membrane cannot be applied due to insufficient filtration speed and insufficient strength.

  Further, the ceramic membrane and metal membrane (filtration membrane 202) having a non-woven cloth structure as shown in FIG. 2 (b) have sufficient strength and can be processed into a flat plate structure as shown in FIG. Although it can be installed, the permeation flow rate is small and the filtration rate of the rapid filtration basin has not been reached. In addition, there is a problem that the fine particles and suspended substances that have entered the inside of the membrane cannot be removed by ordinary washing, and the permeation flow rate tends to decrease with the passage of operating time. In addition, any membrane can be separately provided as a filtration membrane facility after the filtration basin 2.

  On the other hand, the film 15 of anisotropic porous material is a film made of metal or ceramic and having anisotropic pores of 0.1 μm to several tens of μm, as shown in FIG. The water to be treated can be allowed to flow up to / day, and there are no cases where fine particles and suspended substances get inside the membrane and cannot be removed by ordinary washing. That is, in the existing rapid filtration pond, a new facility (site) is unnecessary by providing the membrane 15 using an anisotropic porous material made of metal or ceramic at the lower part of the filter medium layer 3, and These filtration basins and filtration layers can be introduced without significant modification. Thereby, microorganisms and microparticles | fine-particles, such as Cryptosporidium which cannot fully be removed by the conventional filtration process, can be removed (effect of Claim 20).

  Further, the filter medium layer 3 is formed by directly laminating filter media such as natural “silica sand”, “granular activated carbon”, and “anthracite” according to the particle size on the membrane 15, and removal of fine suspended matters is performed by using the membrane 15. By performing a relatively large turbidity component in the filter medium layer 3, clogging of the membrane 15 and the filter medium layer 3 can be suppressed, and the backwash frequency, backwash time, and amount of backwash water can be reduced. Their replacement life can be extended (effect of claim 19).

  Moreover, in the embodiment mentioned above, since the rapid filtration which has a small installation area and high turbidity is used in recent years, the filtration system of the present invention has been described using the rapid filtration pond. However, it can also be applied to highly-treated biological activated carbon tanks, granular activated carbon tanks, and slow filtration ponds with backwashing and leakage of viruses and pathogenic microorganisms.

  When applied to them, the previous two treatment tanks use granular activated carbon as the filter medium, and the filter medium uses silica sand in the slow filter basin having a different structure, but the structure is different from the rapid filter basin. However, the point of combining the filter medium layer 3 of the present invention with the membrane 15 made of an anisotropic porous material is the same as in the case of the rapid filtration pond. In addition, the slow filtration basin has a filtration rate of several meters per day and can be applied to ceramic membranes and metal membranes with a non-woven fabric structure with a slow filtration rate. However, the disadvantage of clogging inside the non-woven fabric structure is considered. Then, the filtration system according to the present invention is superior. Other effects are the same as above.

  Moreover, in this 1st Embodiment, although the case where the existing filtration basin 2 is remodeled to the filtration system 1 of this invention is demonstrated as an example, the existing rapid filtration basin is remodeled to the filtration system 1 of this invention. In that case, it is possible to leave the porous concrete layer 4 and the dispersed gravel layer 5 to prevent the existing filter medium from flowing out (effect of claim 18).

  Also in this configuration diagram, the membrane 15 is laid between the porous concrete layer 4 and the filter medium layer 3, but the porous concrete layer 4 and the dispersed gravel can be obtained even if a filter basin is newly constructed or an existing filter basin is modified. It is preferable that there is no layer 5.

Second Embodiment (corresponding to claims 2 to 8 and 17)
Next, 2nd Embodiment of the filtration system by this invention is described using FIG. 4 and FIG. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 4 shows a film 15 using an anisotropic porous material made of metal or ceramic, and filter media such as natural “silica sand”, “granular activated carbon”, “anthracite”, etc., which have been sieved, are stacked according to particle size. It is a block diagram regarding 2nd Embodiment of the filtration system by this invention which combined the filter medium layer.

[Constitution]
The filtration system 31 shown in this figure is different from the filtration system 1 shown in FIG. 1 in that a membrane 15 using an anisotropic porous material made of metal or ceramic is replaced with two types of membranes 15a and 15b having different pore diameters. A plurality of units 17 each having a space between two membranes by unit structures (beams) 16 are arranged in parallel with the pond surface, and the backwashing method is a membrane 15a and a filter medium layer. 3 and the membrane 15b, the backwash water introduction pipe 18 and the backwash drain discharge pipe 19 are connected between the membranes 15a and 15b to adjust the amount of water. Is connected to each.

  The lower membrane 15a is a membrane using an anisotropic porous material having pores of 0.1 μm to several tens of μm, and the upper membrane 15b has pores larger than the pores of the membrane 15a and is made of silica sand or the like. The filter medium is smaller than the particle diameter of the filter medium so that it does not flow out. When the main purpose is removal of Cryptosporidium, the size of Cryptosporidium is 4 to 6 μm. Therefore, in order to ensure the removal, it is preferable that the pore diameter of the film 15a is 4 μm.

  Further, it is desirable that the air introduction pipe 13 for backwashing is connected between the membranes 15a and 15b in the same manner as the backwash water introduction pipe 18. However, when the filtration system of the present invention is introduced into an existing rapid filtration pond, the equipment connected to the existing catchment basin 8 may be used as it is as shown in FIG.

[Action]
And in this filtration system 31, when to-be-processed water is introduce | transduced from the upper direction of the filtration pond 2, the suspended substance in to-be-processed water will fall in the filter medium layer 3 by gravity, and while flowing in the filter medium, sand It will be removed from the water to be treated.

  Next, a substance larger than each pore is trapped on the membrane surface by the sieving action of the membranes 15a and 15b using the anisotropic porous material having pores of 0.1 μm to several tens of μm. The filtered water that has passed through the pores passes through the porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete plate 6, and is stored in the water collecting basin 8, and then sent to the next water purification treatment step (not shown). At this time, the speed at which the water to be treated flows through the filter medium layer 13 and the membranes 15a and 15b using the anisotropic porous material is about 8 to 10 cm per minute (filtration speed 120 to 150 m / day).

  In order to prevent clogging of the filter medium, the filter medium layer 3 uses “anthracite” having a large particle diameter and a small specific gravity in the upper part, and silica sand having a small particle diameter and a large specific gravity in the lower part.

  In addition, when clogging occurs in the membranes 15a and 15b and the filter medium layer 3, clogging occurs by introducing backwash water from the backwash water introduction pipe 9 at the bottom and flowing water from the bottom to the top. Is removed from the membranes 15 a and 15 b and the filter medium layer 3 and drained from the backwash drainage discharge pipes 10 and 19.

  The backwashing is composed of two stages. In the first stage, the filter medium in the filter medium layer 3 is made into a fluid state by backwash water, and the filter medium particles collide and friction with each other due to a local short circuit flow or small vortex. And the shearing force of the water stream promote separation of adhering turbidity and separate. In the second stage, as the valve 12 is opened, the filter medium and the suspended matter separated from the membranes 15a and 15b are discharged from the backwash water discharge pipes 10 and 19 and sent to a wastewater treatment process (not shown).

Further, in the air cleaning method, in combination with the backflow cleaning, air is blown from the air introduction pipe 13 to peel off turbidity adhering to the filter medium. In the backwashing, any cleaning method is performed. There are various methods such as blowing air and water at the same time, or blowing air for several minutes and then introducing water, and the amount of air is 0.8-1. The valves 11, 14, and 20 are adjusted so that 5 m ³ / (min · m ² ) and the amount of water are 0.6 to 0.8 m ³ / (min · m ² ), respectively. At this time, the total amount introduced from the backwash water introduction pipes 9 and 18 is adjusted so as to be the value. That is, backwashing water is introduced from the backwashing water introduction pipe 9 so that the amount of water is 0.1 to 0.5 m ³ / (min · m ² ), and the rest is introduced from the backwashing water introduction pipe 18. .

When only the film 15a is clogged, only the film 15a is back-washed. At that time, backwash water is introduced from the backwash water introduction pipe 9 at 0.1 to 0.5 m ³ / (min · m ² ), and the same amount or the water to be treated remaining on the upper portion of the membrane 15a A slightly added amount of water is discharged from the backwash drain discharge pipe 19.

[effect]
In the second embodiment, the following new effect can be obtained while obtaining the same effect as in the first embodiment.

  By using two membranes 15a and 15b having different pore diameters, suspended substances larger than the pores of the respective membranes 15a and 15b are captured on the respective membrane surfaces. As a result, it is possible to reduce clogging due to suspended substances in the membrane 15a which has a small pore diameter and is easily clogged, and it is possible to reduce the number of invalid pores blocked due to clogging. As a result, the filtration rate (flow rate) equivalent to rapid filtration can be sufficiently secured, and the backwash cycle and replacement life can be extended. Further, the backwash water introduction pipe 18 and the backwash drainage pipe 19 can be connected between the membranes 15a and 15b, and the backwash water amount in the membrane 15a and the backwash water amount in the filter medium layer 3 can be changed (invoice). Effect of item 2).

  Here, the influence of the amount of backwash water on the membranes 15a and 15b will be described with reference to FIG. FIG. 5 is a diagram showing the relationship between the permeation flow rate of the water to be treated and the pressure with respect to the membranes 15a and 15b made of the anisotropic porous material.

As is apparent from this figure, in the membrane 15a having a small pore diameter capable of capturing Cryptosporidium, the water pressure applied to the membrane 15a increases as the permeate flow rate increases. Further, when 0.6 to 0.8 m ³ / (min · m ² ) of backwash water necessary to make the filter medium flowable is passed through the membrane 15a into the filter medium layer 3, the membrane 15a The pressure loss of the backwashing water introduction pump is increased, the running cost such as electricity bill is increased, and the initial cost is increased by improving the pressure resistance performance of the membranes 15a and 15b, the water collecting tank 8 and the like.

That is, if only clogging of the membrane 15a is to be removed, a large amount of backwashing water is not required, so that the backwashing water introduction pipe 9 reverses at 0.2 to 0.3 m ³ / (min · m ² ). Wash water is introduced, backwash water is introduced from the introduction pipe 18 at 0.4 to 0.6 m ³ / (min · m ² ), and the filter medium is brought into a fluid state 0.6 to 0.8 m ³ / ( Min · m ² ) water quantity is secured. Here, since the membrane 15b has a large pore diameter, the pressure loss does not increase even when the backwash water is flowed at 0.4 to 0.6 m ³ / (min · m ² ). ).

  Depending on the quality of the water to be treated (raw water), the clogging period of the membrane 15a does not coincide with the clogging period of the filter medium layer 3 because the pore diameter is small. That is, the optimum interval of the period for performing the backwashing is different, and it is not necessary to backwash both at the same time each time. And since the backwash drainage pipe 19 is connected to the upper part of the membrane 15a, only the membrane 15a can be backwashed, and the membrane 15a, the membrane 15b and the filter medium layer 3 are individually or simultaneously optimally Backwashing can be performed with the amount of water (effects of claims 3, 4, 5 and 6).

  On the other hand, at the time of filtration (filtration speed 150 m / day), the pressure loss of the membranes 15a and 15b must be added, and the amount of the resistance of the sedimentation basin 2 is increased accordingly. For example, in the sedimentation basin 2 where the pressure loss is less than 0.005 MPa, the resistance increase must be added by 50 cm. However, if the turbidity of the membrane 15b is taken into consideration and the type of the filter medium of the filter medium layer 3 and the method of pulling it are optimized, the increase in filter resistance can be reduced.

  Next, unitization of the films 15a and 15b will be described with reference to FIG. FIG. 6 is a view of the filtration pond 2 as viewed from above. Usually, the filtration pond 2 has an area of several meters to several tens of square meters, and the slow filtration is wider than the rapid filtration. It is difficult to manufacture or install an anisotropic porous membrane of such a large area with metal or ceramic, which is not only costly and insufficient in strength but also difficult to replace and clean.

  Therefore, in the second embodiment, the membranes 15a and 15b and the unit structures (beams) 16 that support them are used to form a unit 17 that can exchange membranes, and a plurality of the same units 17 are provided below the filter medium layer 3. Fix them in parallel so that they are on the same layer surface. The size of each unit 17 is a unit of several tens of cm to several m square. Thereby, those problems can be solved. In addition, since metal and ceramic are used as materials, heating regeneration can be achieved by unitization, and the amount of cleaning chemicals used can be reduced (effect of claim 17).

<< Third Embodiment >> (corresponding to claim 10)
Next, a third embodiment of the filtration system according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment or 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 7 shows a film 15 using an anisotropic porous material made of metal or ceramic, and a filter medium such as natural “silica sand”, “granular activated carbon”, “anthracite”, etc., which have been sieved, stacked according to particle size. It is a block diagram regarding 3rd Embodiment of the filtration system by this invention which combined the filter medium layer.

[Constitution]
The filtration system 32 shown in this figure is different from the filtration system 1 shown in FIG. 1 in that the membrane 15 shown in FIG. 1 is introduced into the air intake pipe 13 of the water collecting basin 8 formed in the lower part of the filtration basin 2 and backwash water introduction. The membrane 15 is provided on the lower side of the tube 9, and the backwash water introduction pipe 18 and the valve 20 for backwashing the membrane 15 are connected to the lower portion of the membrane 15. In addition, when introducing the filtration system 32 of the present invention into the existing rapid filtration pond 2, the air introduction pipe 13 and the backwash water introduction pipe 9 connected to the existing water collecting basin 8 may be used as they are. .

[Action]
In the filtration system 1 shown in FIG. 1, while the water to be treated flows through the route of the filter medium layer 3 → the membrane 15 → the porous concrete layer 4 → the dispersed gravel layer 5 → the perforated concrete plate 6 → the catchment 8. In the filtration system 32 shown in this figure, the filter medium layer 3 → the porous concrete layer 4 → the dispersed gravel layer 5 → the perforated concrete plate 6 → Only the order of the membrane 15 → the water collecting tank 8 is provided, and the action relating to the turbidity treatment is not different from the filtration system 1 shown in FIG. However, the backwashing method for removing clogging of the membrane 15 and the filter medium layer 3 is different from the filtration system 1 shown in FIG.

  Backwashing consists of two stages. In the first stage, the filter medium of the filter medium layer 3 is made into a fluid state by backwash water, and the collision / friction between the filter medium particles due to local short circuit flow or small vortex and water flow. The shearing force of the material promotes the separation of adhering turbidity and separates it. In the second stage, as the valve 12 is opened, the filter medium and the suspended matter separated from the membrane 15 are discharged from the backwash water discharge pipe 10 and sent to a separate wastewater treatment process. In the air cleaning method, air is blown from the air introduction pipe 13 together with the backflow cleaning, and the turbidity adhering to the filter medium is peeled off.

Further, in the backwashing, any of the cleaning methods is performed. There are various methods such as blowing air and water at the same time, blowing air for several minutes and then introducing water. The valves 11, 14, and 20 are adjusted so that 1.5 m ³ / (min · m ² ) and the amount of water is 0.6 to 0.8 m ³ / (min · m ² ). At this time, the total amount of backwash water introduced from the backwash water introduction pipes 9 and 18 is adjusted so as to reach that value. That is, from the backwash water introduction pipe 9, the amount of water is introduced from 0.1 to 0.5 m ³ / (min · m ² ), and the rest is introduced from the backwash water introduction pipe 18.

[effect]
In the third embodiment, the following new effect can be obtained while obtaining the same effect as in the first embodiment.

  First, since the filter media layer 3 and the membrane 15 are physically separated by the porous concrete plate 4 and the dispersed gravel layer 5 and the like, the pores of the membrane 15 are not blocked by the filter media of the filter media layer 3. Thus, each pore of the membrane 15 is prevented from becoming invalid. As a result, the filtration rate (flow rate) equivalent to rapid filtration can be sufficiently secured, and the backwash cycle and replacement life can be extended. Further, since the backwash water introduction pipe 9 for backwashing the filter medium layer is connected to the upper side of the membrane 15 and the backwash water introduction pipe 18 for membrane backwashing is connected to the lower side of the membrane 15, the membrane 15 The amount of backwash water in the inside and the amount of backwash water in the filter medium layer 3 can be changed (effect of claim 10). Note that the influence of the backwash flow rate on the membrane 15 has already been described with reference to FIG. 5 in the description of the second embodiment.

In the membrane 15 having a small pore diameter capable of capturing Cryptosporidium, the water pressure applied to the membrane 15 increases as the permeate flow rate increases. Further, when 0.6 to 0.8 m ³ / (min · m ² ) of backwash water required to make the filter medium flowable is passed through the film 15 into the filter medium layer 3, Therefore, the initial cost increases due to the increase in the size of the backwash water introduction pump, the increase in running cost such as electricity bill, and the pressure resistance performance of the membrane, the water collecting tank 8 and the like.

If the clogging of the membrane 15 is only to be removed, the amount of backwashing water is not so large, so that the backwashing water introduction pipe 18 is 0.2 to 0.3 m ³ / (min · m ² ). The washing water is introduced, and from the backwashing water introduction pipe 9, the backwashing water is introduced at 0.4 to 0.6 m ³ / (min · m ² ), and 0.6 required to make the filter medium fluid. A water amount of ˜0.8 m ³ / (min · m ² ) is secured.

  On the other hand, at the time of filtration (filtration rate 150 m / day), the pressure loss of the membrane 15 has to be added, and the amount of resistance of the sedimentation basin 2 increases accordingly. In sedimentation basin 2 with a loss of less than 0.005 MPa, the resistance increase must be added by 50 cm. However, if the turbidity of the membrane 15 is taken into consideration and the type of the filter medium of the filter medium layer 3 and the method of pulling it are optimized, the increase in filter resistance can be reduced.

  Moreover, in this 3rd Embodiment, when introducing the filtration system 32 of this invention into the existing filtration basin 2, the air introduction pipe | tube 9 designed by the specification of the capacity | capacitance optimized for the washing | cleaning of the filter material layer 3, and reverse Since the washing water introduction pipe 9 can be used as it is, only a slight improvement is required, and the renewal cost can be reduced. In addition, when clogging in the membrane 15 cannot be removed only by backwashing, only the membrane 15 can be replaced without replacing the filter medium of the filter medium layer 3, and the running cost can be reduced.

  In addition, the membrane 15 does not need to withstand the weight of the filter medium, and has a strength structure that can withstand only the water pressure with respect to the permeate flow rate. Although omitted in the third embodiment, a backwash drainage pipe may be connected to the top of the membrane 15. In this case, similarly to the second embodiment, only the membrane 15 can be back-washed, and the membrane 15 and the filter medium layer 3 can be back-washed individually or simultaneously with the optimum amount of water.

<< 4th Embodiment >> (Corresponding to Claim 9)
Next, 4th Embodiment of the filtration system which concerns on this invention is described using FIG. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment-3rd Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 8 shows a film 15 using an anisotropic porous material made of metal or ceramic, and filter media such as natural “silica sand”, “granular activated carbon”, “anthracite”, etc., which are sieved, are laminated according to particle size. It is a block diagram regarding 4th Embodiment of the filtration system by this invention which combined the filter medium layer.

[Constitution]
The filtration system 33 shown in this figure is different from the filtration system 1 shown in FIG. 1 in that the porous concrete layer 4, the dispersed gravel layer 5 and the perforated concrete plate 6 shown in FIG. The unit 17 composed of the film 15 and the unit structure (beam) 16 is used as a support structure for the filter medium layer 3.

[Action]
And in the filtration system 33 shown in this figure, instead of the porous concrete layer 4, the dispersed gravel layer 5 and the perforated concrete plate 6 shown in FIG. 1, a unit composed of a membrane 15 and a unit structure (beam) 16. 17 supports the filter medium layer 3. Further, in the filtration system 1 shown in FIG. 1, while the water to be treated flows through the filter medium layer 3 → the membrane 15 → the porous concrete layer 4 → the dispersed gravel layer 5 → the perforated concrete plate → the water collecting basin 8, the filter medium layer 3 and the film 15. In the filtration system 33 shown in this figure, the suspended material in the water to be treated is turbidized, but the order of the filter medium layer 3 → the membrane 15 (unit 17) → the water collecting tank 8 is different. The other actions are not different from the filtration system 1 shown in FIG.

[effect]
In the fourth embodiment, the following new effect can be obtained while obtaining the same effect as in the first embodiment.

  By eliminating the porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete plate 6, it is possible to reduce the management cost by simplifying the equipment, and there is no risk of bacteria etc. breeding in those holes, Moreover, since the unit 17 is periodically exchanged and cleaned, management can be facilitated. In addition, when the filter basin 2 is newly laid, the laying cost can be reduced to the extent that the porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete plate 6 are not required (effect of claim 9).

  On the other hand, when this filtration system 33 is introduced into the existing filtration basin 2, it is necessary to remove the existing porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete plate 6, but only by the amount of these units removed. 17 is lowered to increase the height difference between the pond surface of the filtration pond 2 and the membrane 15, thereby increasing the water pressure applied to the membrane 15, and the pressure loss (filter resistance) with respect to the permeation flow rate of the water to be treated. Can be compensated.

<< 5th Embodiment >> (Corresponding to Claims 15 and 16)
Next, a fifth embodiment of the filtration system according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment-4th Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 9 shows a film 15 using an anisotropic porous material made of metal or ceramic, and filter media such as natural “silica sand”, “granular activated carbon”, “anthracite”, etc., which are sieved, are laminated according to particle size. It is a block diagram regarding 5th Embodiment of the filtration system by this invention which combined the filter medium layer.

[Constitution]
The filtration system 34 shown in this figure is different from the filtration system 31 shown in FIG. 4 in that the porous concrete layer 4, the dispersed gravel layer 5 and the perforated concrete plate 6 shown in FIG. The unit 17 composed of the two films 15a and 15b using the material and the unit structures (beams) 16a and 16b is used as the support structure of the filter medium layer 3, and the wavelength is 254 nm above and below the film 15a. That is, the ultraviolet lamps 22 and 23 from the sterilization line are installed.

[Action]
In the filtration system 34 shown in this figure, instead of the porous concrete layer 4, the dispersed gravel layer 5 and the perforated concrete plate 6 shown in FIG. 4, a unit 17 composed of a membrane 15 and a unit structure (beam) 16. In the filtration system 32 shown in FIG. 4, the water to be treated is filtered medium layer 3 → membrane 15b → membrane 15a → porous concrete layer 4 → dispersed gravel layer 5 → porous concrete plate 6 → water collecting tank. In the filtration system 34 shown in this figure, the filter medium layer 3 → the membrane 15b → the membrane 15a → the water collecting tank, while the suspended matter in the water to be treated is turbidized by the filter medium layer 3 and the membrane 15 The order is 8.

  Further, Cryptosporidium, bacteria, microorganisms, and viruses in the suspended substance captured on the surface of the membrane 15a are inactivated by ultraviolet rays (sterilization lines) having a wavelength of 254 nm that are irradiated from the ultraviolet lamp 23.

  On the other hand, microorganisms, viruses, and the like that are smaller than the pores of the membrane 15a are not captured by the membrane 15a and pass therethrough, but when temporarily stored in the catchment basin 8, the wavelength irradiated from the ultraviolet lamp 22 is reduced. It is inactivated by 254 nm ultraviolet light (sterilization line).

  Other functions are not different from those of the second embodiment.

[effect]
In the fifth embodiment, the following new effect can be obtained while obtaining the same effect as in the second embodiment.

  By eliminating the porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete plate 6, it is possible to reduce the management cost by simplifying the equipment, and there is no risk of bacteria etc. breeding in those holes, Moreover, since the unit 17 is periodically exchanged and cleaned, management can be facilitated. Moreover, when laying the filtration pond 2 newly, the laying cost can be reduced because the porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete board 6 are not required.

  On the other hand, when this filtration system 33 is introduced into the existing filtration basin 2, it is necessary to remove the existing porous concrete layer 4, the dispersed gravel layer 5, and the perforated concrete board 6, but only by the amount of these units removed. 17 is lowered, and the water pressure applied to the membranes 15a and 15b is increased by increasing the level difference between the water surface of the filtration pond 2 and the membranes 15a and 15b, and the pressure loss with respect to the permeation flow rate of the water to be treated. It can compensate for (the resistance rise).

  Further, by irradiating the water to be treated with ultraviolet light, which is a germicidal line having a wavelength of 254 nm, from the ultraviolet lamp 23 provided on the upper part of the film 15a, Cryptosporidium, bacteria in the suspended substance captured on the surface of the film 15a Can inactivate microorganisms and viruses. That is, in the anisotropic porous material membrane 15a, the suspended matter trapped on the membrane surface is exposed to a water flow (water pressure) for a longer time than the non-woven cloth-like filtration membrane, so that the membrane 15a permeates. However, it can be inactivated and killed by exposure to the germicidal line for a sufficient time before passing through the membrane 15a, and the safety of filtered water can be improved (effect of claim 15).

  On the other hand, including the case where the ultraviolet lamp 23 cannot be provided on the upper part of the film 15 as in the first, third and fourth embodiments, microorganisms and viruses smaller than the pores of the film 15a In this case, they can be inactivated by ultraviolet rays that are germicidal rays having a wavelength of 254 nm irradiated from the ultraviolet lamp 22 provided at the lower part of the membrane 15a. The safety of filtered water can be improved (effect of claim 16).

<< 6th Embodiment >> (Corresponding to Claims 11, 13, and 14)
Next, a sixth embodiment of the filtration system according to the present invention will be described with reference to FIG.

  FIG. 10 is a configuration diagram relating to a sixth embodiment of the filtration system according to the present invention in which the membrane 15 using an anisotropic porous material made of metal or ceramic having different pore sizes is multi-staged.

[Constitution]
The filtration system 35 shown in this figure includes a multistage filtration membrane layer 24 in which membranes 15a to 15f using anisotropic porous materials made of metals or ceramics having different pore sizes are combined in the filtration pond 2; The perforated concrete board 6 that supports the perforated concrete board 6, the supporting beam 7 that supports the perforated concrete board 6, and the water collecting basin 8 at the periphery thereof.

  The lowermost membrane 15a has a pore diameter of 0.1 μm to several tens of μm, and the upper membranes 15b to 15e have larger pore diameters as they become upper, and the uppermost membrane 15f has several pores. The hole diameter is about mm. In addition, when remodeling the existing rapid filtration basin to the filtration system 35 of this embodiment, the perforated concrete board of a rapid filtration basin is diverted as the perforated concrete board 6. FIG.

  However, the perforated concrete plate 6 may be eliminated by increasing the strength of the multi-stage filtration membrane layer 24 and by supporting the membranes 15a to 15f by themselves. Further, the existing filter medium, porous concrete layer, and dispersed gravel layer are removed, and the multistage filtration membrane layer 24 is provided. In addition, a backwash water introduction pipe 9 for introducing backwash water for washing the multistage filtration membrane layer 24 and a valve 11 are connected to the water collecting tank 8 at the lower part of the filtration basin 2, while the multistage filtration is performed. Above the membrane layer 23, a backwash drainage discharge pipe 10 for discharging backwash drainage and a valve 12 are connected. When the main purpose is removal of Cryptosporidium, the size of Cryptosporidium is 4 to 6 μm. Therefore, in order to ensure the removal, the pore diameter of the membrane 15a is preferably less than 4 μm.

  The multistage filtration membrane layer 24 includes a plurality of unit structures (beams) 16a to 16f formed in several tens of centimeters to several m squares, and a plurality of stages supported by these unit structures (beams) 16a to 16f. It is comprised by the film | membranes 15a-15f, and has become the structure which arranged each unit a-33f in parallel with the pond surface.

[Action]
And in this filtration system 35, when to-be-processed water is introduce | transduced from the upper direction of the filtration pond 2, it will descend | fall in the multistage filtration membrane layer 24 with gravity, and it will suspend in to-be-processed water while permeate | transmitting each film | membrane 15a-15f. Turbid substances larger than the pores of the respective membranes 15a to 15f are captured on the surfaces of the respective membranes 15a to 15f. That is, by the sieving action of each of the membranes 15a to 15f for each pore diameter, the smaller suspended substance is removed from the water to be treated as it goes down. Further, on the surface of the membrane 15a having anisotropic pores of 0.1 μm to several tens of μm at the lowest stage, pathogenic protozoa, bacteria, bacteria larger than the pores (0.1 μm to several tens of μm) containing cryptosporidium Algae are captured and removed from the water to be treated. The filtered water that has passed through the pores of the membrane 15 a passes through the perforated concrete plate 6, is stored in the water collecting tank 8, and is then sent to the next water purification treatment process (not shown).

  At this time, the speed at which the water to be treated flows down the multistage filtration membrane layer 24 using the anisotropic porous material is 1 when the existing rapid filtration basin is modified and the filtration system 35 of the present invention is applied. It becomes about 8-10 cm (filtration speed 120-150 m / day) per minute. This is because the peripheral equipment such as existing equipment and piping is made according to the specifications. On the other hand, when applied to a slow filtration basin, the pore diameters of the membranes 15a to 15f at each stage are adjusted to a filtration rate of several meters / day in accordance with the specification of the filtration rate.

In addition, although the pressure loss is small in the membrane 15f having large pores, the water pressure applied to the membrane increases as the permeate flow rate increases in the membrane 15a having a small pore diameter capable of capturing Cryptosporidium. Therefore, when applied to a rapid filtration basin with a filtration rate of 150 m / day, that is, a permeate flow rate of 0.1 m ³ / min · m ² , the pressure loss becomes 0.005 MPa only with the membrane 15 a, so that the membranes 15 a to 15- The total pressure loss of 15f causes the resistance to increase. Further, the clogging of the films 15a to 15f further worsens. Moreover, when laying the filter basin 2 and the filtration layer newly, since it does not depend on the filtration speed of the existing equipment, it is preferably 1 to 1000 m / day in consideration of the filtration resistance rise. Design between ~ 200m / day.

  Further, in the multistage filtration membrane layer 24, in order to prevent clogging of the respective membranes 15a to 15f, a membrane 3f having a pore diameter of about several millimeters is disposed at the uppermost portion, and pores are gradually formed in the lower membrane. A film 3a having a pore diameter of 0.1 μm to several tens of μm is disposed at the lowermost portion.

In addition, as long as the permeation | transmission flow velocity is larger than each film | membrane 15a-15f made from anisotropic porous material with the same pore diameter, you may substitute with a mesh etc. In particular, each of these films 15a to 15f can be replaced as they become higher. In addition, when clogging occurs in the membranes 15a to 15f, the clogging is caused by introducing backwash water from the backwash water introduction pipe 9 in the lower portion and flowing water from the bottom to the top. It is removed from the membranes 15a to 15f and discharged together with the suspended substances captured by the membranes 15a to 15f from the discharge pipe 10 in which the valve 12 is opened as backwash drainage. At this time, the valve 11 is adjusted so that the backwash water amount is 0.1 to 0.8 m ³ / (min · m ² ).

[effect]
As described above, in the sixth embodiment, the membranes 15a to 15f using the anisotropic porous material have the pores in the same direction as the permeation direction of the supplied water and the ratio of the space occupied in the material (spatial rate ) Is large, the filtration resistance of the supplied water is reduced, and the permeation flow rate can be increased as compared with the microfiltration membrane and the ultrafiltration membrane usually used for water supply. That is, when the membranes 15a to 15f are introduced into the conventional rapid filtration pond, the multistage filtration membrane layer 24 must flow down at a filtration rate of 120 to 150 m / day. However, with conventional microfiltration membranes and ultrafiltration membranes made of organic polymer materials, ceramic membranes and metal membranes with a non-woven fabric structure, it depends on the pressure applied (in the case of a filtration pond, loss head), but a few meters The treated water can only flow at a filtration rate of / day. On the other hand, in the anisotropic porous membrane used in the sixth embodiment, the water to be treated can flow up to several hundred m / day and backwashing can be performed (claim 11). 13 effects).

  At this time, a relatively large turbid component is removed by the membrane 15f having relatively large pores arranged in the upper stage, and fine suspended matters are removed by the membrane 15a having small pores arranged in the lower stage. So, at a permeation rate of 1 to 1000 m / day, backwashing water can be flown to eliminate clogging of each film 15a to 15f, and clogging of each film 15a to 15f can be suppressed. The backwash time and the amount of backwash water can be reduced, and their replacement life can be extended (effect of claim 14).

  In addition, the unit filtration membrane layer 24 is configured by arranging the units 17a to 17f of several tens of centimeters to several meters square so as to be parallel to the pond surface. It can be easily installed at a low cost and with sufficient strength for ordinary filtration ponds 2 that are thicker, or even slower filtration than rapid filtration, and can be easily installed and cleaned with chemicals. Can be made. Furthermore, since it is made of metal or ceramic, it can be heated and regenerated by unitization, and the amount of cleaning chemicals used can be reduced.

  Other effects are the same as above.

<< Seventh embodiment >> (corresponding to claims 12, 15, and 16)
Next, a seventh embodiment of the filtration system according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as 6th Embodiment, and the overlapping description is abbreviate | omitted.

[Constitution]
FIG. 11 shows a seventh embodiment of the filtration system of the present invention, in which membranes 15a to 15f using anisotropic porous materials made of metals or ceramics having different pore sizes are used as multistage filtration membranes 24 combined in multiple stages. It is a block diagram regarding embodiment.

  The filtration system 36 shown in this figure is different from the filtration system 35 shown in FIG. 10 in that backwash water introduction pipes 25a to 25e are connected between the membranes 15a to 15f using an anisotropic porous material. Valves 26a to 26e for adjusting the amount of backwash water are installed in the backwash water introduction pipes 25a to 25e, and an ultraviolet lamp 22 that emits a sterilization line having a wavelength of 254 nm in the water collecting tank 8 and each space between the films 15a and 15b. , 23 is installed.

[Action]
In this filtration system 36, the backwashing method and exposure to ultraviolet rays (sterilization lines) having a wavelength of 254 nm emitted from the ultraviolet lamps 22 and 23 before and after the water to be treated passes through the membrane 15a are sixth. Different from the embodiment.

  First, the backwashing method different from the sixth embodiment will be described.

When clogging occurs in the membranes 15a to 15f, backwash water (backwash water) is introduced from the backwash water introduction pipes 25a to 25e arranged below the membranes 15a to 15f, and multistage filtration is performed. By causing water to flow from the bottom to the top of the membrane layer 24, the clogged ones of the membranes 15a to 15f are removed and released together with suspended substances trapped on the upper surfaces of the membranes 15a to 15f. Then, the water is drained from the backwash drainage pipe 10 through the valve 11. Backwash water ^is in the range of ^{0.1~0.8m 3 / (min · m 2} ), to adjust valve 9,26A～26e, 12 a. Usually, the amount of backwash water increases as the upper stage of the membranes 15a to 15f increases. However, if there is a membrane with a lot of suspended solids that are clogged or trapped, the membrane is backflowed. Adjust the amount of water to be increased.

  Next, the effect | action by the ultraviolet lamps 22 and 23 different from 6th Embodiment is demonstrated.

  Microorganisms such as Cryptosporidium that were not captured by the membranes 15b to 15f when the water to be treated that had been turbidized by the membranes 15b to 15f passed through the membrane 15a having smaller pores while flowing down the multistage filtration membrane layer 24 Suspended matter containing is removed from the treated water. Moreover, after the filtrate water which passed the film | membrane 15a is temporarily stored by the catchment basin 8, it is discharged | emitted from the filtration basin 2 and sent to the next treatment process.

  Then, Cryptosporidium, bacteria, microorganisms, and viruses in the suspended substance captured on the upper surface of the membrane 15a are inactivated by ultraviolet rays (sterilization lines) having a wavelength of 254 nm irradiated from the ultraviolet lamp 23. Microorganisms, viruses, and the like that are smaller than the pores of the membrane 15a that are not captured by the membrane 15a and pass through the ultraviolet ray (wavelength 254 nm) by the ultraviolet lamp 22 when the filtered water is temporarily stored in the catchment 8. Inactivate by irradiation with germicidal lines.

[effect]
As described above, in the seventh embodiment, the backwash water introduction pipes 25a to 25e are connected between the films 15a to 15f using the anisotropic porous material, and the backwash water introduction pipes 25a are connected to the backwash water introduction pipes 25a. -25e are provided with valves 26a to 26e for adjusting the amount of backwash water, and when clogging occurs in the membranes 15a to 15f, backwash water introduction pipes 25a to 25e on the lower side of the membranes 15a to 15f By introducing washing water (back washing water) and causing water to flow from the bottom to the top of the multi-stage filtration membrane layer 24, the clogging substances of the membranes 15a to 15f are removed, and the reverse through the opened valve 11 The water can be drained from the washing / drainage pipe 10. At this time, depending on the degree of clogging of each of the membranes 15a to 15f, the amount of backwash water for the clogged membrane is increased, and the total amount of backwash water is 0.1 to 0.8 m ³ / (min · m ² ) The valves 9, 26a to 26e, 12 can be individually adjusted so as to fall within the range of ² ).

  Further, by irradiating the water to be treated with ultraviolet light (sterilization line) having a wavelength of 254 nm from the ultraviolet lamp 23 provided on the upper part of the film 15a, Cryptosporidium, bacteria in the suspended matter captured on the surface of the film 15a. Can inactivate microorganisms and viruses. That is, in the anisotropic porous material membrane 15a, the suspended matter trapped on the membrane surface is exposed to a water flow (water pressure) for a long time, so that the risk of permeation through the membrane 15a is higher than that of a filtration membrane having a non-woven cloth structure. high. However, it can be inactivated and killed by being exposed to the sterilization line for a sufficient time before permeation, and the safety of filtered water can be improved (effect of claim 16).

  Further, by irradiating the filtered water that has passed through the membrane 15a with ultraviolet rays (sterilization line) having a wavelength of 254 nm from the ultraviolet lamp 22 provided in the lower portion of the membrane 15a or in the water collecting tank 8, Bacteria, microorganisms and viruses that pass through without being captured by the membrane 15a can be inactivated. The ultraviolet lamp 22 can also inactivate Cryptosporidium, bacteria, microorganisms, and viruses that have permeated through the membrane 15a when the suspended substances captured on the surface of the membrane 15a are exposed to a water flow (water pressure) for a long time. Moreover, since the ultraviolet lamp 22 can be installed in the water collecting tank 8, it is not necessary to make the structure for providing the lamp 23 in the unit 17a of the multistage filtration membrane layer 24, and it can be simplified (effect of claim 15).

  If the multistage filtration membrane layer 24 is structurally permitted, an ultraviolet lamp can be provided in the space between the membranes 15c to 15f to greatly improve the disinfection performance for the water to be treated.

It is a lineblock diagram showing a 1st embodiment of a filtration system by the present invention. It is a structural diagram explaining the microfiltration membrane used by the conventional filtration system, an ultrafiltration membrane, and the filtration membrane of a non-woven cloth structure. A filtration membrane made of a metal or ceramic non-woven cloth structure used in a conventional filtration system and a filtration membrane made of an anisotropic porous material made of metal or ceramic used in the filtration system shown in FIG. FIG. It is a block diagram which shows 2nd Embodiment of the filtration system by this invention. It is a figure which shows the relationship between a permeation | transmission flow rate and a pressure when using the filtration membrane manufactured with the metal anisotropic porous material with the filtration system shown in FIG. It is a block diagram explaining the unit manufactured with the metal anisotropic porous material used with the filtration system shown in FIG. It is a block diagram which shows 3rd Embodiment of the filtration system by this invention. It is a block diagram which shows 4th Embodiment of the filtration system by this invention. It is a block diagram which shows 5th Embodiment of the filtration system by this invention. It is a block diagram which shows 6th Embodiment of the filtration system by this invention. It is a block diagram which shows 7th Embodiment of the filtration system by this invention. It is explanatory drawing of the anisotropic porous material used in each embodiment of the filtration system by this invention. It is the schematic which shows the structure of the 1st example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is the schematic which shows the modification of the 1st example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is the schematic which shows the structure of the 2nd example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is the schematic which shows the structure of the 3rd example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is the schematic which shows the modification of the 3rd example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is the schematic which shows the structure of the 4th example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is the schematic which shows the modification of the 4th example of the anisotropic porous material used by each embodiment of the filtration system by this invention. It is a system flow figure showing the coagulation sedimentation processing and filtration basin of the water purification plant conventionally known. It is a block diagram which shows the high-speed filtration pond of the water purification plant conventionally known.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31-36 ... Filtration system 2 ... Filtration pond 3 ... Filter media layer 4 ... Porous concrete layer 5 ... Dispersed gravel layer 6 ... Perforated concrete board 7 ... Support beam 8 ... Catchment 9 ... Backwash water introduction pipe 10 ... Reverse Washing drainage discharge pipe 11, 12, 14 ... Valve 13 ... Air introduction pipe 15, 15a-15f ... Membrane 16 ... Unit structure 17 ... Unit 18 ... Backwash water introduction pipe 19 ... Backwash drainage discharge pipe 20, 21 ... Valve 22, 23 ... UV lamp 24 ... Multi-stage filtration membrane layer 25a-25e ... Backwash water introduction pipe 26a-26e ... Bulb

Claims (20)

In a filtration system that filters treated water using a filtration pond,
A membrane using an anisotropic porous material is provided on the lower side of the filtration pond, and a filter medium for filtering suspended substances in the water to be treated is filled on the upper side of the filtration pond.
A filtration system characterized by that. The filtration system according to claim 1,
The membrane using the anisotropic porous material is composed of a plurality of stages having different pore sizes.
A filtration system characterized by that. The filtration system according to claim 1 or 2,
A backwash drainage pipe is connected to the upper side of the membrane of the filtration basin, and the backwash drainage discharged when the membrane is backwashed is discharged from the backwash drainage pipe.
A filtration system characterized by that. The filtration system according to any one of claims 1 to 3,
A backwash water introduction pipe is connected to the upper side of the membrane of the filtration basin, and through this backwash water introduction pipe, backwash water is introduced into the filtration basin, and the filter medium is washed.
A filtration system characterized by that. The filtration system according to claim 3 or 4,
Utilizing part or all of the backwash water for the membrane as backwash water for the filter medium, backwashing the membrane and the filter medium simultaneously,
A filtration system characterized by that. The filtration system according to claim 4 or 5,
The cleaning of the membrane and the cleaning of the filter medium each have a different amount of water or a backwash cycle,
A filtration system characterized by that. The filtration system according to any one of claims 4 to 6,
The amount of backwash water of the membrane is 0.1 to 0.5 m ³ / (min · m ² ),
A filtration system characterized by that. The filtration system according to any one of claims 4 to 7,
The total amount of the backwashing water amount of the membrane and the backwashing water amount of the filter medium is adjusted to be 0.6 to 0.8 m ³ / (min · m ² ).
A filtration system characterized by that. The filtration system according to any one of claims 1 to 8,
The structure consisting of the membrane supports the filter medium,
A filtration system characterized by that. The filtration system according to any one of claims 1 to 9,
The membrane was provided in a catchment basin at the bottom of the filtration pond,
A filtration system characterized by that. In a filtration system that filters treated water using a filtration pond,
A plurality of membranes composed of a plurality of anisotropic porous materials having different pore diameters are stacked on the lower side of the filtration pond so that the pore diameters are sequentially increased toward the upper side,
A filtration system characterized by that. The filtration system according to claim 11,
For each membrane, change the backwash water amount or backwash cycle of each membrane,
A filtration system characterized by that. The filtration system according to claim 11 or 12,
The filtration rate of the filtration pond is adjusted to 1 to 1000 m / day, preferably 1 to 200 m / day.
A filtration system characterized by that. The filtration system according to any one of claims 11 to 13,
Each of the membranes is back-washed at a permeation rate of 1-1000 m / day.
A filtration system characterized by that. The filtration system according to any one of claims 1 to 14,
An ultraviolet irradiation facility was provided at the bottom of the film,
A filtration system characterized by that. The filtration system according to any one of claims 1 to 15,
An ultraviolet irradiation facility was provided on the top of the film,
A filtration system characterized by that. The filtration system according to any one of claims 1 to 16,
A unit structure is provided on the lower side of the filtration pond, and the membrane is disposed in the unit structure in a replaceable manner.
A filtration system characterized by that. The filtration system according to any one of claims 1 to 17,
A membrane using an anisotropic porous material is provided on the lower side of the existing rapid filtration basin or slow filtration basin, and the upper side is filled with a filter medium for filtering suspended substances in the treated water.
A filtration system characterized by that. The filtration system according to any one of claims 1 to 10, 15 to 18,
The filter medium contains any one of sieved natural silica sand, anthracite, granular activated carbon,
A filtration system characterized by that. The filtration system according to any one of claims 1 to 19,
The pore diameter of the membrane is in the range of 0.1 μm or more and less than 10 μm, preferably 4 μm or less.
A filtration system characterized by that.

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