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CN-116322930-B - Filter device, filter system and filter method

CN116322930BCN 116322930 BCN116322930 BCN 116322930BCN-116322930-B

Abstract

Disclosed are a filtration device, a filtration system, and a filtration method which have a high effect of removing hardly decomposable substances. A filter device (10) of the present invention comprises a filter container (11) having a supply port (4) for a liquid to be treated (A) and a discharge port (15) for the liquid to be treated (B), and a tubular filter (12) provided inside the filter container (11), wherein an outer surface (12 f) is a filter surface, and wherein the inside is a passage for the liquid to be treated (B), and wherein an adsorbent (N) for adsorbing the substance (E) which is difficult to decompose is laminated on the outer surface (12 f) of the filter (12) in a state before filtration to form an adsorbent layer (47).

Inventors

  • NISHIMURA AKIRA

Assignees

  • 流机工程株式会社

Dates

Publication Date
20260512
Application Date
20210125
Priority Date
20201023

Claims (5)

  1. 1. A filter device for removing a hardly decomposable substance contained in a liquid to be treated, comprising: a filter container having a supply port for the liquid to be treated and a discharge port for the liquid to be treated, and A pleated filter provided in the filter vessel, having a filter surface on an outer surface thereof and a passage for a treatment liquid therein, the pleated filter being formed in a tubular shape by bending a flat filter medium into a corrugated shape, A cleaning device which is arranged outside the pleated filter and ejects cleaning liquid to the outer surface of the pleated filter, In a pre-filtration state, an adsorbent layer is provided on the outer surface of the pleated filter, The adsorbent layer is laminated with an adsorbent for adsorbing the refractory substance, The adsorbent layer is made up of a plurality of layers, In the layer of the adsorbent material, A2 nd adsorbent layer is laminated on the outer surface of the 1 st adsorbent layer, the 1 st adsorbent layer is laminated with particles of the 1 st adsorbent for adsorbing the refractory substance, the 2 nd adsorbent layer is laminated with particles of the 2 nd adsorbent for adsorbing the refractory substance, The average particle diameter of the particles of the 1 st adsorbent layer is larger than the average particle diameter of the particles of the 2 nd adsorbent layer, The average particle diameter of the particles of the 1 st adsorbent layer is larger than the gaps of the pleated filter.
  2. 2. The filter device according to claim 1, wherein the 1 st adsorbent is activated carbon, and the 2 nd adsorbent is activated carbon having an average particle diameter smaller than that of the activated carbon of the 1 st adsorbent.
  3. 3. The filtration device of claim 1, wherein the 1 st adsorbent is prussian blue and the 2 nd adsorbent is activated carbon having an average particle size smaller than the prussian blue of the 1 st adsorbent.
  4. 4. A method of filtering, comprising: An adsorbent layer forming step of passing a solution containing an adsorbent adsorbing a hardly decomposable substance through a pleated filter, and forming an adsorbent layer on an outer surface of the pleated filter, wherein the outer surface of the pleated filter is a filter surface and a passage for a treatment liquid is provided therein, and bending a flat filter medium into a corrugated shape to form a plurality of pleats and a tubular shape; an adsorption-filtration step of passing a liquid to be treated through the pleated filter having the adsorbent layer formed thereon and filtering the liquid while adsorbing the hardly decomposable substance to the adsorbent layer, and A cleaning step of ejecting a cleaning liquid from a cleaning device disposed outside the pleated filter to an outer surface of the pleated filter, and peeling off a cake formed on the outer surface of the pleated filter and the adsorbent layer; The adsorbent layer forming step includes: A1 st adsorbent layer forming step of passing a1 st solution containing 1 st adsorbent particles having an average particle diameter larger than gaps of the pleated filter through the pleated filter to form a1 st adsorbent layer formed by stacking the 1 st adsorbent particles on an outer surface of the pleated filter, and And a2 nd adsorbent layer forming step of passing a2 nd solution containing 2 nd adsorbent particles having an average particle diameter smaller than that of the 1 st adsorbent particles through the pleated filter to form a2 nd adsorbent layer in which the 2 nd adsorbent particles are laminated on the outer surface of the 1 st adsorbent layer.
  5. 5. The filtration method according to claim 4, wherein a purging step is provided after the end of the adsorption-filtration step and before the start of the cleaning step, wherein a gas is supplied to the passage of the treatment liquid in the pleated filter, and the passage of the treatment liquid and a gap between the outer surface of the pleated filter and the filtration vessel are filled with the gas.

Description

Filter device, filter system and filter method Technical Field The present invention relates to a filtration apparatus, a filtration system, and a filtration method for removing a hardly decomposable substance contained in a liquid to be treated. Background In the POPs convention (Stockholm convention on persistent organic pollutants), there are regulations for the production, use, reduction of emissions, etc. of persistent organic pollutants (PERSISTENT ORGANIC POLLUTANTS: POPs) to be disposed of. The POPs are a general term for chemical substances which are hardly decomposed in the environment, are easily accumulated in living beings, and have high mobility and diffusion, and in the annex a of the convention, perfluorooctanoic acid (PFOA) and the like are exemplified as the target substance, and in the annex B, perfluorooctane sulfonic acid (PFOS) and the like are exemplified as the target substance. The proposal was added in 2002 at 8, requiring the obligation of the proposal to be fulfilled. Among the substances specified by the POPs convention, the PFOS and PFOA are listed as water quality control target setting items in Japan from the year 2020, month 4 and day 1, and the target value is 0.00005mg/L (provisional) in terms of the sum of the amounts of these two substances. The japanese environmental province also investigated river, lake, sea area, groundwater, and gushing water. Thus, there is a general need in society for techniques for removing POPs such as PFOS and PFOA. In addition, since substances other than POPs that are difficult to decompose (chemical substances that are difficult to decompose in natural environments) may cause environmental pollution (e.g., deterioration of water quality), removal thereof is desired. The determination of whether a chemical substance is a good decomposable substance or a difficult decomposable substance is based on the following criteria described in "test method and determination criteria related to determination of compliance with monitoring chemical substances" prescribed in japan (final revision level was 23, 4, 22 days). Namely, good decomposability means (1) that in 3 test vessels, the degree of decomposition based on BOD is 60% or more for 2 or more and 60% or more for 3 on average. (2) Meanwhile, it was confirmed by direct analysis such as HPLC and GC that no decomposition products were formed. When the test result of the test method defined by the document does not satisfy the above-described criterion, and when biodegradation continues even after the end of the test (e.g., a tendency to rise) is suggested based on the BOD curve or the like, the determination can be made based on the test result of the OECD test criterion 302C. On the other hand, the difficult decomposability means that the decomposability is not good. Examples of the method for purifying the liquid containing the above-mentioned hardly decomposable substance (including POPs, the same applies hereinafter) include (1) an RO membrane treatment method, (2) an ion exchange resin adsorption method, (3) an activated carbon adsorption method, (4) an ozone oxidation decomposition method, and (5) an ultraviolet/photocatalyst method. Further, as conventional techniques related to the present invention, there are inventions disclosed in patent documents 1 to 5. Patent document 1 discloses a method for operating a water treatment facility using an immersion type membrane filtration device. In this operation method, a powdered activated carbon mixture obtained by adding powdered activated carbon to raw water in advance is flowed into a membrane filtration tank, or raw water is flowed into the membrane filtration tank and powdered activated carbon is added to form powdered activated carbon mixture, a treatment target substance such as a trace amount of organic matters in raw water is adsorbed to the powdered activated carbon, and solid-liquid separation of the powdered activated carbon mixture in the membrane filtration tank is performed by an immersion type membrane filtration device provided in the tank. In this case, the amount of water to be taken out by the membrane filtration is set to 99% or more relative to the amount of water flowing into the membrane filtration tank, and the powdered activated carbon is kept at a high concentration in the membrane filtration tank, whereby adsorption of the substance to be treated can be promoted. Patent document 2 discloses a drainage treatment method. In this method, an adsorbent capable of adsorbing a soluble harmful component is fed into raw water from an adsorbent feeding section, at least the soluble harmful component is adsorbed on the adsorbent, and then filtration treatment is performed by a filtration unit such as a membrane separation device, the adsorbent having the adsorbed harmful component and solid harmful component are separated from the raw water, and then the cleaning effluent of the filtration unit is introduced into an oxidation promo