JP2006192390A - Washing method of separation membrane module and water treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the washing method of a separation membrane module in which a chemical solution is made to pass through the filter membrane of the separation membrane module from a permeating water side with the module dipped in liquid in a water treatment tank, requiring little time and labor in associated work for washing the module, the filter membrane can be uniformly washed like chemical washing in a chemical washing tank, and stable washing effect can be obtained. <P>SOLUTION: In this washing method of the separation membrane modules 2a-2d dipped in liquid in the water treatment tank 1 and filtering liquid in the tank, a cylindrical enclosing body 24 enclosing the separation membrane module 2a to be washed is formed prior to washing, in such a state that the separation membrane modules 2a-2d are dipped in the liquid in the water treatment tank 1, then the chemical solution is made to pass through the filter membrane of the separation membrane module 2a enclosed by the cylindrical enclosing body 24 from a permeating water side. After washing, the enclosing body 24 is removed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a separation membrane module cleaning method for immersing in a liquid in a water treatment tank such as a biological reaction tank and filtering the liquid in the tank, and a water treatment apparatus capable of performing this cleaning method. It is.

  In purification treatments such as sewage and organic industrial wastewater, the separation membrane module is immersed in the activated sludge mixture in the biological reaction tank as a water treatment tank. The sludge mixed liquid is filtered to obtain a purified permeate (permeate) from the permeate side (permeate side) of the filtration membrane of the separation membrane module. In the separation membrane module that separates and filters the activated sludge mixed liquid in this way, the contaminants adhere to the membrane surface on the side in contact with the activated sludge mixed liquid by the filtration operation. For this reason, it is necessary to recover the suction differential pressure (permeation flux) of the separation membrane module by performing chemical cleaning to remove the membrane surface adhering substance.

  As a method for cleaning the separation membrane module, the separation membrane module is moved from the biological reaction tank to a separate chemical cleaning tank, and the chemical cleaning is performed, and the separation membrane module is immersed in the liquid in the biological reaction tank. In-line cleaning (for example, Japanese Examined Patent Publication No. 6-65371) is known in which chemical liquid is washed back by allowing the chemical liquid to pass through the filtration membrane of the separation membrane module from the permeate side.

  Off-line cleaning can clean the filtration membrane uniformly and provides a stable cleaning effect. However, the permeated water in the separation membrane module is extracted, the air scrubbing pipe is disassembled, the separation membrane module is lifted from the tank, and the chemicals are washed. Substantial work required for washing, such as moving to the tank and returning to the biological reaction tank after washing, takes a lot of work. In-line cleaning, on the other hand, is easier and less time-consuming for the accompanying work required for cleaning, but it is not performed by backwashing by immersing the separation membrane module in a chemical solution. Since it is washing by backwashing in the filled activated sludge mixed liquid, it is difficult to wash the filtration membrane of the separation membrane module uniformly, and there is a problem that a clogged portion remains in part.

For this reason, with regard to the cleaning of the separation membrane module, the above-mentioned in-line cleaning is carried out at a frequency of about once / month, and this alone is not sufficient. The actual situation is that it takes a lot of time and effort, and there is a need to eliminate the need for offline cleaning that causes a reduction in filtration efficiency.
Japanese Examined Patent Publication No. 6-65371 (FIG. 1)

  An object of the present invention is to wash a separation membrane module by allowing a chemical solution to pass through the filtration membrane of the separation membrane module from the permeate side while the separation membrane module is immersed in the liquid in the water treatment tank. In this case, a separation membrane that does not require much labor for incidental work required for washing, and can wash the filtration membrane uniformly and obtain a stable washing effect like washing in a chemical solution in a chemical solution washing tank. An object of the present invention is to provide a module cleaning method and a water treatment apparatus.

  In order to solve the above problems, the present invention takes the following technical means.

  The invention of claim 1 is a cleaning method of a separation membrane module in which the liquid in the tank is filtered by immersing in the liquid in the water treatment tank, while the separation membrane module is immersed in the liquid in the water treatment tank. In this state, prior to cleaning, a cylindrical enclosure that surrounds the separation membrane module to be cleaned is formed, and then the filtration membrane of the separation membrane module surrounded by the cylindrical enclosure is removed from the permeate side. The separation membrane module cleaning method is characterized by removing the cylindrical envelope after permeation and cleaning.

  According to a second aspect of the present invention, in the method for cleaning a separation membrane module according to the first aspect, before removing the cylindrical enclosure after the cleaning, the cylindrical enclosure body fluid containing the chemical solution is taken out of the water treatment tank. It is characterized by this.

  According to a third aspect of the present invention, there is provided the method for cleaning a separation membrane module according to the first or second aspect, wherein the cylindrical enclosure moves the surrounding plate and is submerged in the liquid in the tank prior to the cleaning, It is formed by being guided and supported by a surrounding plate guide support body installed corresponding to the arrangement of the separation membrane module inside.

  According to a fourth aspect of the present invention, in the method for cleaning a separation membrane module according to the first or second aspect, the cylindrical enclosure is formed by extending a bellows contracted during filtration operation prior to cleaning. It is characterized by.

  The invention according to claim 5 includes a water treatment tank, a separation membrane module immersed in the liquid in the tank of the water treatment tank, and a filtration membrane of the separation membrane module as an outer surface of the liquid in the tank of the water treatment tank. Filtration means for permeating from the inside of the membrane to the permeate side, cleaning means for allowing the chemical solution to permeate the filtration membrane of the separation membrane module from the permeate side and ooze out from the outer surface of the filtration membrane, Prior to cleaning, a cylindrical envelope surrounding the separation membrane module to be cleaned is formed in a state where the separation membrane module is immersed in the liquid in the water treatment tank, and after the cleaning, the cylindrical envelope is formed. And a cylindrical enclosure formation removing means for removing the water.

  A sixth aspect of the present invention is the water treatment apparatus according to the fifth aspect of the present invention, wherein the cylindrical enclosure for taking out the liquid in the cylindrical enclosure containing the chemical solution out of the water treatment tank prior to removing the cylindrical enclosure after washing. It further comprises a bodily fluid discharge means.

  A seventh aspect of the present invention is the water treatment apparatus according to the fifth or sixth aspect, wherein the cylindrical enclosure formation removing means is installed in an enclosure plate and the water treatment tank corresponding to the arrangement of the separation membrane module. Prior to cleaning, the surrounding plate guide support body is moved, and the surrounding plate is moved to form a cylindrical envelope body that surrounds the separation membrane module to be cleaned by the surrounding plate, and is guided to the surrounding plate guide support body. And a surrounding plate moving means for moving the surrounding plate supported by the surrounding plate guide support to remove the cylindrical envelope after cleaning. It is characterized by this.

  The invention according to claim 8 is the water treatment apparatus according to claim 5 or 6, wherein the cylindrical enclosure formation removing means has a bellows that contracts during a filtration operation and expands prior to washing. It is characterized by being.

  The method or apparatus of the present invention forms a cylindrical enclosure surrounding the separation membrane module to be cleaned prior to cleaning, with the separation membrane module immersed in the liquid in the water treatment tank. The filtration membrane of the separation membrane module in which the chemical solution is surrounded by the cylindrical enclosure is permeated from the permeated water side, and after washing, the cylindrical enclosure is removed. Therefore, the chemical solution that oozes from the separation membrane module in the cylindrical enclosure is replaced with the original solution in the tank, and the separation membrane module in the cylindrical enclosure is subjected to chemical cleaning by backwashing while being immersed in the chemical solution. In addition, it takes less time to form and remove the cylindrical enclosure, and it can be done in a short time.Furthermore, the filtration membrane can be washed uniformly like a chemical solution in a chemical cleaning tank, and the cleaning effect is stable. Can be obtained. Therefore, it is not necessary to perform off-line cleaning, and the filtration processing efficiency can be improved. In addition, since the chemical solution washing is performed in a state in which the separation membrane module is surrounded by the cylindrical enclosure, the diffusion of the chemical solution exuding from the separation membrane module can be prevented, so that the conventional cylindrical enclosure is not formed. Compared with the in-line cleaning, it is possible to shorten the chemical cleaning time and the chemical usage.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram of a configuration of an example of a water treatment apparatus for carrying out the method of the present invention.

  In FIG. 1, 1 is a biological reaction tank as a water treatment tank to which treated water (raw water) is supplied and which contains a mixed liquid of treated water and activated sludge. In this example, four hollow fiber membrane modules 2a to 2d from the first to the fourth are immersed in the activated sludge mixed solution in the biological reaction tank 1. The hollow fiber membrane modules 2a to 2d as the separation membrane module are immersed in the activated sludge mixed solution in a state where they are suspended in an upright position having a number of hollow fiber membranes (filtration membranes) extending in the vertical direction. The external pressure type. 3 is an aeration device arranged on the bottom surface of the biological reaction tank 1, and 4 is an aeration blower for supplying aeration air to the aeration device 3. Air scrubbing air supply pipes 5 are provided at the lower ends of the hollow fiber membrane modules 2a to 2d so that air scrubbing air is supplied from the air scrubbing blowers 6 through the air scrubbing on / off valves 5a to 5d, respectively. It is arranged.

  The hollow fiber membrane modules 2a to 2d each have a water collecting chamber (the permeated water side of the hollow fiber membrane communicates with the water collecting chamber) at the upper part via the permeated water on-off valves 7a to 7d. The permeated water discharge pipe 8 having the suction pump 9 is communicated. Thereby, at the time of filtration operation, the inside of the hollow fiber membranes of the hollow fiber membrane modules 2a to 2d is sucked by the suction pump 9 to create a pressure difference between the inside and the outside of the membrane, whereby the activated sludge mixed liquid is removed from the hollow fiber membrane module 2a. The permeated water filtered by ~ 2d is taken out of the tank. The permeated water on / off valves 7a to 7d and the permeated water outlet pipe 8 having the suction pump 9 are used to pass the activated sludge mixed liquid in the biological reaction tank 1 through the filtration membranes of the hollow fiber membrane modules 2a to 2d from the outer surface. The filtration means for making it permeate | transmit to the permeated water side inside a film | membrane is comprised.

  Reference numeral 10 denotes a chemical tank. 11 is a chemical solution supply pipe having one end connected to the chemical solution tank 10 and having an on-off valve 12 and an infusion pump 13 in order from the chemical solution tank 10 side, and the hollow fiber membrane modules 2a to 2d each have the water collecting chamber, The chemical solution supply pipe 11 communicates with the chemical solution injection on / off valves 14a to 14d. Reference numeral 15 denotes a washing water tank. A washing water supply pipe 16 having an opening / closing valve 17 communicates with the washing water tank 15 from the upstream side of the injection pump 13 in the chemical solution supply pipe 11. The chemical solution tank 10, the chemical solution supply pipe 11 having the on-off valve 12 and the injection pump 13, the chemical solution injection on-off valves 14 a to 14 d, the cleaning water tank 15, and the cleaning water supply pipe 16 having the on-off valve 17 are used to supply the chemical solution. It constitutes a cleaning means for allowing the filtration membranes of the hollow fiber membrane modules 2a to 2d to permeate from the permeate side and ooze from the outer surface of the filtration membrane.

  FIG. 2 is a plan view for explaining the surrounding plate guide support in the water treatment apparatus shown in FIG.

  As shown in FIG. 2, in the biological reaction tank 1, the surrounding plate guide support body is previously installed corresponding to arrangement | positioning of the hollow fiber membrane modules 2a-2d. The surrounding plate guide support is provided so as not to interfere with the air diffuser 3. In this example, as the surrounding plate guide support, four surrounding plate guide supports 21A extending in the vertical direction with an insertion gap having an L-shaped cross section are installed, and the insertion gap having a T-shaped cross section is provided. Six enveloping plate guide supports 21B having the vertical direction are provided. The surrounding plate guide supports 21A and 21B are made of, for example, vinyl chloride having chemical resistance.

  Here, an example of the configuration of the hollow fiber membrane modules 2a to 2d will be described more specifically. 7 is a cross-sectional view showing a configuration example of the hollow fiber membrane module in FIGS. 1 and 5, and FIG. 8 is a plan view showing the arrangement of the hollow fiber membrane bundle fixed to the upper fixing portion of the hollow fiber membrane module shown in FIG. FIG.

  As shown in FIG. 7, the hollow fiber membrane module M (2a to 2d) includes a lower fixing portion 60, an upper fixing portion 70 positioned above the lower fixing portion 60 at a predetermined interval, and a lower side A plurality of support members (not shown) extending in the vertical direction for supporting the fixing portion 60 and the upper fixing portion 70 while maintaining a distance therebetween, and the lower fixing portion with the lower end portion sealing the film end A plurality of hollow fiber membranes 51 fixed to the upper fixing portion 70 with the upper end portion being opened to the membrane end. A plurality of hollow fiber membranes 51 extending in the vertical direction are formed into a plurality of hollow fiber membrane bundles 52 in which a predetermined number of plural hollow fiber membranes 51 are bundled at the upper end portion and bonded together at the upper fixing portion 70 side. A plurality of hollow fiber membrane bundles 52 are fixed to the upper fixing portion 70.

  The upper fixing portion 70 includes a cylindrical body 71, a circular upper plate 72 having a permeate outlet 72a and attached to the upper side of the cylindrical body, and a circular lower plate 73 having a membrane bundle through-hole and attached to the lower side of the cylindrical body. It is comprised by. Inside the upper fixing portion 70, a plurality of hollow fiber membrane bundles 52 are arranged on a plurality (eight in the illustrated example) of radiation centered on the radial center of the upper fixing portion 70, as shown in FIG. And fixed to the upper fixing portion 70. This is to make it difficult for impurities and sludge to accumulate near the roots of the hollow fiber membrane bundles 52 exposed from the upper fixing portion 70. 52 a is a hollow fiber membrane bundle coupling portion where a plurality of hollow fiber membrane bundles 52 are bonded with an adhesive, and 74 is an adhesive portion for fixing the hollow fiber membrane bundle 52 to the upper fixing portion 70. When assembling the upper fixing portion 70, the hollow fiber membrane bundle 52 is passed through each membrane bundle through-hole of the circular lower plate 73, and then the hollow space of the hollow fiber membrane bundle 52 is filled with an adhesive so as to be hollow in the cylindrical body 71. The thread membrane bundle 52 is bonded and fixed, and then the circular lower plate 73 is attached to the cylindrical body 71.

  A water collection chamber 75 is formed in the upper portion of the upper fixing portion 70, and the permeated water collection chamber 75 is formed at the opening at the upper end of the hollow fiber membrane 51 constituting each hollow fiber membrane bundle 52. It communicates, and is defined by the lower surface of the circular upper plate 72, the inner wall surface of the cylindrical body 71, the upper end surface of the hollow fiber membrane bundle 52, and the adhesive portion 74. A permeate outlet 72 a connected to the water collection chamber 75 is connected to the permeate outlet pipe 8 described above.

  The lower fixing portion 60 includes a cylindrical body 61 having the same inner diameter as the cylindrical body 71 of the upper fixing portion 70 and a plurality of air introduction holes 63 for air scrubbing, and an upper portion in the cylindrical body 61. And a bubble passing member 62 having a disk shape attached to the.

  On the upper surface of the bubble passage member 62, the lower end portion of the hollow fiber membrane 51 forming the hollow fiber membrane bundle 52 is distributed almost uniformly in the portion other than the air introduction hole 63 to seal the end of the hollow fiber membrane. In this state, the adhesive is fixed. Further, the tip portion of the air scrubbing air supply pipe 5 is located on the lower end side of the cylindrical body 61. Air is press-fitted into the cylindrical body 61 from the air scrubbing air supply pipe 5, and air from the air reservoir 64 below the bubble passage member 62 is discharged as air bubbles from the air introduction hole 63 into the liquid in the tank. ing. The deposits on the surface of the hollow fiber membrane are removed by the collision of the bubbles with the hollow fiber membrane 51 and the upward flow of the liquid in the tank caused by the rising bubbles.

  Next, with reference to FIG.1, FIG3 and FIG.4, the washing | cleaning method implemented in the water treatment apparatus shown in FIG. 1 is demonstrated. FIG. 3 is a plan view for explaining a cylindrical enclosure by an enclosure plate in the water treatment apparatus shown in FIG. FIG. 4 is a side view for explaining the state of cleaning the first hollow fiber membrane module in the water treatment apparatus shown in FIG.

  Here, the case where the 1st hollow fiber membrane module 2a is wash | cleaned is demonstrated. First, among the hollow fiber membrane modules 2a to 2d during the filtration operation, the permeated water on / off valve 7a and the air scrubbing on / off valve 5a for the first hollow fiber membrane module 2a to be cleaned this time are closed.

  Next, by using a crane (not shown) as a surrounding plate moving means attached to the biological reaction tank 1, the U-shaped surrounding plate 22 extending in the vertical direction is moved from the storage location outside the tank to the living body. It is submerged in the reaction tank 1 and inserted into the surrounding plate guide supports 21A and 21B at the position corresponding to the first hollow fiber membrane module 2a so as to drop from above. Thereby, the U-shaped surrounding plate 22 is supported in an upright posture. Next, again using a crane, the plate-shaped surrounding plate 23 having the same length as the U-shaped surrounding plate 22 and extending in the vertical direction is moved from the storage place outside the tank to move into the biological reaction tank 1. And is inserted into the surrounding plate guide supports 21A and 21B at the position corresponding to the first hollow fiber membrane module 2a so as to be dropped from above. As a result, a cylindrical enclosure 24 that surrounds (encloses) the first hollow fiber membrane module 2 a is formed by the U-shaped enclosure plate 22 and the flat enclosure plate 23. The surrounding plates 22 and 23 are made of, for example, vinyl chloride having chemical resistance. A U-shaped notch through which the air scrubbing air supply pipe 5 passes is provided at the lower end of the flat envelope plate 23.

  When the cylindrical enclosure 24 is formed, the on-off valve 12 and the on-off valve 14a for injecting medicinal solution are opened, and the medicinal solution (for example, sodium hypochlorite aqueous solution) from the medicinal solution tank 10 is supplied to the first hollow by the injecting pump 13. A predetermined amount is injected into the hollow fiber membrane module 2a and held for a predetermined time so that the hollow fiber membrane of the yarn membrane module 2a can permeate from the permeate water side (secondary side) to the outer surface of the membrane.

  Thus, in the state where the first hollow fiber membrane module 2a is surrounded by the cylindrical enclosure 24, the chemical solution is passed through the hollow fiber membrane module 2a in the reverse direction (from the inside of the hollow fiber membrane to the outer surface). By injecting into the hollow fiber membrane module 2a, the chemical solution exuding from the hollow fiber membrane module 2a is replaced with the original activated sludge mixed solution on the surface of the hollow fiber membrane, and the hollow fiber membrane module 2a is performed without the cylindrical enclosure 24. Unlike the case, since the chemical solution is washed while being immersed in the chemical solution and hardly affected by the water flow or the like due to the air scrubbing of the other hollow fiber membrane modules 2b to 2d, the hollow fiber membrane is used. Can be cleaned uniformly and a stable cleaning effect can be obtained.

  After the cleaning with the chemical solution, the on-off valve 12 is closed, the on-off valve 17 of the cleaning water supply pipe 16 is opened, a predetermined amount of cleaning water is injected into the first hollow fiber membrane module 2a, and the cleaning with the cleaning water is performed. Do. Thereafter, the enclosure plates 22 and 23 are lifted by the crane and moved out of the tank, whereby the cylindrical enclosure 24 is removed, and the cleaning operation of the first hollow fiber membrane module 2a is completed. After completion of washing, the permeated water open / close valve 7a and the air scrubbing open / close valve 5a are opened, and all the hollow fibers obtained by adding the first hollow fiber membrane module 2a to the three hollow fiber membrane modules 2b to 2d so far are opened. The filtration operation by the yarn membrane modules 2a to 2d is performed. Here, the surrounding plates 22 and 23, the surrounding plate guide supports 21A and 21B, and the crane are immersed in the liquid in the biological reaction tank 1 and the hollow fiber membrane modules 2a to 2d are immersed in the tank prior to washing. A cylindrical envelope body 24 is formed that surrounds the separation membrane module to be cleaned, and after the cleaning, the cylindrical envelope body 24 is removed.

  As described above, when the hollow fiber membrane module 2a is washed in the state where the hollow fiber membrane module 2a is immersed in the liquid in the biological reaction tank 1, the formation of the cylindrical enclosure 24 and the removal thereof are greatly increased. It takes less time and requires less time, and the membrane can be evenly washed as in the chemical solution in the chemical solution washing tank, so that a stable cleaning effect can be obtained. Therefore, it is not necessary to perform off-line cleaning, and the filtration processing efficiency can be improved.

  Further, since the chemical liquid washing is performed in a state in which the hollow fiber membrane module 2a is surrounded by the cylindrical enclosure 24, it is possible to prevent the chemical liquid exuding from the hollow fiber membrane module 2a from being diffused outward. Compared with the conventional in-line cleaning in which the body 24 is not formed, it is possible to shorten the chemical cleaning time and reduce the amount of chemical used.

  In the above embodiment, one hollow fiber membrane module is washed at a time. However, the present invention is not limited to this. In the present invention, a plurality of hollow fiber membrane modules are washed at a time. What is necessary is just to determine suitably the number of the hollow fiber membrane modules wash | cleaned at once according to the number of the hollow fiber membrane modules installed in the reaction tank, the state of filtration operation, etc.

  FIG. 5 is an explanatory diagram of the configuration of an example of another water treatment apparatus for carrying out the method of the present invention. Here, FIG. 5 is characterized in that it includes bellows 25A to 25D. The same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  As shown in FIG. 5, each of the hollow fiber membrane modules 2 a to 2 d is provided with bellows 25 </ b> A to 25 </ b> D that form a bag shape that is open on the top and bottom while being supported by the upper suspension module connection pipe. Yes. The bellows 25A to 25D are made of a chemical-resistant material such as a vinyl chloride sheet, and as shown in FIG. 5, the bellows 25A to 25D are contracted during the filtration operation.

  FIG. 6 is a side view for explaining the state of cleaning the first hollow fiber membrane module in the water treatment apparatus shown in FIG.

  The cleaning method performed in the water treatment apparatus shown in FIG. 5 will be described. As shown in FIG. 6, when the first hollow fiber membrane module 2a is cleaned, the bellows 25A is stretched in the liquid to A cylindrical envelope 26 surrounding the yarn membrane module 2a is formed. When the cylindrical envelope 26 is formed, the hollow fiber membrane module 2a surrounded by the cylindrical envelope 26 is subsequently washed in the same procedure as in the above-described embodiment. When the cleaning is completed, the cylindrical enclosure 26 is removed by contracting the bellows 25A. The contraction / extension of the bellows 25A to 25D is performed, for example, by pulling or loosening a wire rope or chain attached to the bellows body. The bellows 25A to 25D constitute a cylindrical enclosure formation removing unit.

  As described above, when the hollow fiber membrane module 2a is washed while the hollow fiber membrane module 2a is immersed in the liquid in the biological reaction tank 1, the cylindrical enclosure 26 is formed by the bellows 25A and removed. In addition, the filtration membrane can be washed uniformly as in the chemical solution washing in the chemical solution washing tank, and a stable washing effect can be obtained. Therefore, it is not necessary to perform off-line cleaning, and the filtration processing efficiency can be improved. In addition, since the chemical solution washing is performed in a state in which the hollow fiber membrane module 2a is surrounded by the cylindrical enclosure 26, it is possible to prevent the chemical solution exuding from the hollow fiber membrane module 2a from diffusing outward. Compared with the conventional in-line cleaning in which the body 26 is not formed, the chemical cleaning time can be shortened and the chemical usage can be reduced.

  Moreover, in each water treatment apparatus shown in FIG. 1 and FIG. 5 described above, when a chemical solution that reduces the activity of living organisms (activated sludge) in the biological reaction tank 1 (for example, nitric acid aqueous solution) is used, it is cylindrical after washing. Prior to removing the enclosures 24 and 26, it is preferable in terms of biological treatment operation to take out the cylindrical enclosure body fluid containing the chemical solution out of the biological reaction tank 1. Prior to removing the cylindrical enclosures 24 and 26 after the cleaning, the cylindrical enclosure body fluid discharge means for taking out the cylindrical enclosure body fluid containing the chemical solution out of the biological reaction tank 1 is, for example, opened at the tip. In addition, a flexible pipe (hose) whose base end is connected to a waste liquid tank provided outside the biological reaction tank 1 via a pump, and means (for example, a crane) for moving the distal end side of the flexible pipe are provided, The opening of the flexible tube is positioned in the cylindrical enclosures 24 and 26, the liquid containing the chemical solution in the cylindrical enclosures 24 and 26 is sucked, and the inside of the cylindrical enclosures 24 and 26 is the activated sludge mixed liquid. It only has to be replaced. Thereby, the activity fall of the living body (active sludge) resulting from chemical | medical solution washing | cleaning within the cylindrical enclosures 24 and 26 formed in the biological reaction tank 1 can be prevented.

It is composition explanatory drawing of an example of the water treatment apparatus which enforces this invention method. It is a top view for demonstrating a surrounding board guide support body in the water treatment apparatus shown in FIG. It is a top view for demonstrating the cylindrical enclosure by an enclosure board in the water treatment apparatus shown in FIG. It is a side view for demonstrating a mode at the time of wash | cleaning the 1st hollow fiber membrane module in the water treatment apparatus shown in FIG. It is composition explanatory drawing of an example of another water treatment apparatus which enforces this invention method. It is a side view for demonstrating a mode at the time of wash | cleaning the 1st hollow fiber membrane module in the water treatment apparatus shown in FIG. It is sectional drawing which shows one structural example of the hollow fiber membrane module in FIG. 1 and FIG. It is a top view which shows arrangement | positioning of the hollow fiber membrane bundle fixed to the upper side fixing | fixed part of the hollow fiber membrane module shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Biological reaction tank 2a-2d ... Hollow fiber membrane module 5 ... Air supply pipe for air scrubbing 5a-5d ... Air scrubbing on-off valve 6 ... Air scrubbing blower 7a-7d ... Permeated water on-off valve 8 ... Permeated water derivation Pipe 9 ... Suction pump 10 ... Chemical liquid tank 11 ... Chemical liquid supply pipe 12 ... Open / close valve 13 ... Injection pump 14a-14d ... Open / close valve for chemical liquid injection 15 ... Wash water tank 16 ... Wash water supply pipe 17 ... Open / close valves 21A, 21B ... Enveloping plate guide support 22 ... U-shaped enveloping plate 23 ... Flat plate enveloping plate 24 ... Cylindrical enclosure 25A-25D ... Bellows 26 ... Cylindrical enclosure (expanded bellows)
M ... Hollow fiber membrane module

Claims (8)

  In the method for cleaning the separation membrane module, which is immersed in the liquid in the tank of the water treatment tank and filtrates the liquid in the tank, prior to cleaning with the separation membrane module being immersed in the liquid in the tank of the water treatment tank. Forming a cylindrical envelope surrounding the separation membrane module to be cleaned, and then allowing the medicinal solution to pass through the filtration membrane of the separation membrane module surrounded by the cylindrical envelope from the permeate side, after washing, A method for cleaning a separation membrane module, wherein the cylindrical enclosure is removed.   2. The method of cleaning a separation membrane module according to claim 1, further comprising: taking out the liquid in the cylindrical enclosure containing the chemical solution from the water treatment tank prior to removing the cylindrical enclosure after cleaning.   Prior to washing, the cylindrical enclosure is moved by an enclosure plate and submerged in the liquid in the tank, and is guided by an enclosure guide support that is previously installed in the water treatment tank corresponding to the arrangement of the separation membrane module. 3. The method for cleaning a separation membrane module according to claim 1, wherein the separation membrane module is formed by supporting.   The method of cleaning a separation membrane module according to claim 1 or 2, wherein the cylindrical enclosure is formed by stretching a bellows contracted during a filtration operation prior to cleaning. A water treatment tank, and a separation membrane module that is immersed in the liquid in the water treatment tank;
Filtration means for allowing the liquid in the water treatment tank to permeate the filtration membrane of the separation membrane module from the outer surface to the permeate side of the membrane, and permeate the chemical solution from the permeate side of the filtration membrane of the separation membrane module Cleaning means for oozing from the outer surface of the filtration membrane;
Prior to cleaning, a cylindrical envelope surrounding the separation membrane module to be cleaned is formed in a state in which the separation membrane module is immersed in the liquid in the water treatment tank, and after the cleaning, the cylindrical envelope is formed. A water treatment apparatus comprising: a cylindrical enclosure forming / removing means for removing the body.   6. The cylindrical enclosure body fluid discharging means for taking out the cylindrical enclosure body fluid containing the chemical solution to the outside of the water treatment tank prior to removing the cylindrical enclosure body after washing. Water treatment equipment.   The cylindrical enclosure formation removing means includes an enclosure plate, an enclosure guide support installed in the water treatment tank corresponding to the arrangement of the separation membrane module, and a separation membrane module to be cleaned prior to cleaning. Is moved to form a cylindrical enclosure that surrounds the enclosure plate, guided to the enclosure guide support, and supported by the enclosure guide support, and after cleaning, the cylinder enclosure The water treatment apparatus according to claim 5 or 6, further comprising a surrounding plate moving means for moving a surrounding plate supported by the surrounding plate guide support to remove the water.   The water treatment apparatus according to claim 5 or 6, wherein the cylindrical enclosure forming and removing means is configured to have a bellows that contracts during a filtration operation and expands prior to cleaning.