WO2011108589A1 - Method for washing porous membrane module, and fresh water generator - Google Patents

Method for washing porous membrane module, and fresh water generator

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Publication number
WO2011108589A1
WO2011108589A1 PCT/JP2011/054771 JP2011054771W WO2011108589A1 WO 2011108589 A1 WO2011108589 A1 WO 2011108589A1 JP 2011054771 W JP2011054771 W JP 2011054771W WO 2011108589 A1 WO2011108589 A1 WO 2011108589A1
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Prior art keywords
water
membrane module
porous membrane
membrane
module
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PCT/JP2011/054771
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French (fr)
Japanese (ja)
Inventor
智宏 前田
池田 啓一
寛生 高畠
谷口 雅英
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東レ株式会社
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D65/00Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
    • B01D65/02Membrane cleaning or sterilisation ; Membrane regeneration
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/441Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2321/00Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2321/00Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
    • B01D2321/04Backflushing
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2321/00Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
    • B01D2321/16Use of chemical agents
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2325/00Details relating to properties of membranes
    • B01D2325/02Details relating to pores or pososity of the membranes
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/442Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/70Treatment of water, waste water, or sewage by reduction
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/72Treatment of water, waste water, or sewage by oxidation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00Specific treatment goals
    • C02F2303/16Regeneration of sorbents, filters

Abstract

Disclosed are a fresh water generator and a method for washing a porous membrane module, wherein counter-pressure wash is performed using water that contains an oxidizing agent, after which water that contains a reducing agent is filtered by means of a porous membrane module.

Description

Cleaning method and the fresh water generator of the porous membrane module

The present invention, in the fresh water generator for obtaining a porous membrane film filtered water raw water, a method of cleaning a porous membrane module, and a fresh water generator.

Recently, the fresh water generator and sewage secondary treatment water reuse, etc. from sea water, brine has a high removal efficiency of the desalination efficiency and toxic substances, since maintenance is easier, reverse osmosis membrane or a nanofiltration membrane (hereinafter, referred to as a semi-permeable membrane together these) semipermeable membrane module with are frequently used.

If the raw water is not clear, to prevent clogging of the semi-permeable membrane, in order to increase the membrane life, sand filtration in front of the semi-permeable membrane modules, activated carbon filtration, MF membrane filtration, pre-processing means such as a UF membrane filtration that is usually provided, capture reliably suspended solid or microorganisms, MF membrane to remove, UF membrane is preferably used. When performing filtering operation of the MF membrane / UF membrane, with the membrane filtration water, the amount of deposition of proteins and the like derived from humus and microorganisms on the membrane surface and membrane pores will continue to increase, decrease or membrane filtration water rise of the differential pressure becomes a problem.

Therefore, introducing air bubbles into the raw water side of the membrane, to oscillate the film, and air cleaning scraping off adhering material of the membrane surface by bringing touch each membrane with each other, the filtration method of the film or membrane filtration water in the opposite direction clarified water pushing pressure, physical cleaning of counter pressure cleaning or the like to eliminate the contaminants adhering to the membrane surface, membrane pores have been put to practical use.

To further enhance the cleaning effect, or by adding sodium hypochlorite in the opposite 圧洗 water purification Patent Document 1, a method or using ozone-containing water in Patent Document 2 reverse 圧洗 water purification has been proposed. Oxidizing agent has the effect of decomposing and removing organic substances such as proteins derived from humic substances and microorganisms adhering to the membrane surface and membrane pores.

However, after oxidative degradation with an oxidizing agent an organic matter attached to the membrane surface, since the oxidizing agent on the secondary side in the pipe in or filtration side membrane module is remaining high for the membrane filtration water immediately after the start of filtration often it includes oxidant concentration. Semipermeable membranes, especially since the film material is likely to cause oxidative degradation by oxidizing agents for the semipermeable membrane of polyamide, or rinse thoroughly the secondary side in the pipe in or filtration side membrane module raw water and membrane filtered water, it is necessary or reduced neutralizing an oxidizing agent by adding a reducing agent such as sodium thiosulfate or sodium bisulfite sulfate.

Only wash away the secondary side in the pipe in or filtration side membrane module raw water and the membrane filtration water efficiently residual oxidant from the inability reduction neutralization, adding a reducing agent always in front of the semi-permeable membrane module caused the need, chemicals cost is high. In fresh water generating method for filtering raw water while adding an oxidizing agent, a method for cleaning the primary side of the regular membrane module in Patent Document 3 bisulfite solution is a reducing agent is periodically Patent Document 4 methods of reverse pressure washing with washing water containing a reducing agent has been proposed. However, since the oxidizing agent is contained in the membrane filtration water between cleaning and cleaning with a reducing agent, resulting the need to add the reducing agent always in front of the semi-permeable membrane modules, chemical cost increases .

After back pressure washing with Patent Document 5, an oxidizing agent, a method of performing a reverse pressure washing with a reducing agent it has been proposed. However, since it is used many back pressure cleaning, water recovery and productivity water drops.

Japanese Patent 2001-79366 JP Japanese Patent 2001-187324 JP Japanese Patent 2006-305444 JP Japanese Patent 2008-29906 JP Japanese Patent No. 3380114 Publication

In the membrane separation apparatus for membrane filtration in a porous membrane module raw water, a method to prevent the leakage of the oxidizing agent to the subsequent stage, water recovery and productivity water is high, effectively washing the porous membrane module, and desalination to provide an apparatus.

To solve the above problems, the present invention relates to the following (1) to (12).
(1) after performing the counterpressure washed with water containing an oxidizing agent, it comprises filtering the water containing a reducing agent by a porous membrane module, a method of cleaning a porous membrane module.
(2) The method of cleaning a porous membrane module according to at least a portion of the membrane filtration water of water containing a reducing agent, to (1), which comprises discharging from the bypass line provided on the back pressure cleaning lines to the outside of the system.
(3) at least part of the membrane filtration water of water containing a reducing agent, a bypass line provided on the back pressure cleaning line comprises water to membrane filtration water reservoir, according to (1) or (2) the method of cleaning a porous membrane module.
(4) before or after filtering the water containing a reducing agent, which comprises counter-pressure washing a porous membrane module with a membrane filtration water, a porous membrane according to any one of (1) to (3) module method of cleaning.
(5) after performing the counterpressure washed with water containing an oxidizing agent, comprises holding a predetermined time water containing oxidizing agent to the porous membrane in the module, any of (1) to (4) the method of cleaning a porous membrane module according to one paragraph.
(6) during the performance of counter pressure washing with water containing an oxidizing agent, before the implementation, after the implementation, and the porous membrane time holding the water containing the oxidizing agent in the module at least partially to the air cleaning comprises performing, (1) - (5) the method of cleaning a porous membrane module according to any one of.
(7) at least part of the membrane filtration water obtained by filtration using a porous membrane module comprises filtering with a semipermeable membrane, (1) to the porous according to any one of (6) method of cleaning a membrane module.
(8) a porous membrane module,
From the secondary side and the back pressure cleaning unit for supplying the primary side of the porous membrane module membrane filtration water in the porous membrane module,
And the porous membrane module of the membrane oxidant supply unit for supplying an oxidizing agent from the secondary side to the line for supplying the primary side of the filtered water the porous membrane module,
A reducing agent supply unit for supplying a reducing agent to the primary side of the porous membrane module,
Desalination device that includes a.
(9) comprising said porous membrane bypass line connected to the line and the outside of the system discharge line for supplying a membrane filtration water on the primary side from the secondary side of the module, fresh water generator according to (8).
(10) containing said porous membrane bypass line connected line and the membrane filtration water reservoir supplying the membrane filtration water on the primary side from the secondary side of the module, according to (8) or (9) desalination equipment.
(11) to the primary side of the porous membrane module further includes an air supply unit for supplying a gas, (8) fresh water generator according to any one of - (10).
(12) including a semipermeable membrane modules for filtering at least a portion of the membrane filtration water obtained by filtration using a porous membrane module (8) to the fresh water generator according to any one of (11) .

According to the cleaning method of the membrane module of the present invention, the membrane separation apparatus for membrane filtration in a porous membrane module raw water, to prevent leakage of oxidant to the subsequent stage, high water recovery and productivity water is effectively it is possible to provide a method of cleaning a porous membrane module.

Figure 1 is a schematic flow diagram of a fresh water generator to which the present invention is applied.

The embodiments of the present invention, including a porous membrane pressure type hollow fiber membrane module (hereinafter, the hollow fiber membrane module) as an example the case of membrane filtration using a filtration device will be described below with reference to FIG. 1 . However, not that the invention is not limited to the following embodiments.

Fresh water generator can be applied cleaning method of the present invention, for example, as shown in FIG. 1, a raw water storage tank 1 for storing raw water, raw water supply pump 2 for supplying raw water, opening between the time of raw water supply become the raw water supply valve 3, a hollow fiber membrane module 4 for filtering the raw water, and air bleed valve 5 is opened, for example, to reverse pressure washing or air washing, and filtration valve 6 which is opened when the filtration, the hollow fiber membranes a membrane filtration water storage tank 7 for storing the filtered water, a semi-permeable membrane module 8, a booster pump 9 supplies the hollow fiber membrane filtration water semipermeable membrane module 8, the hollow fibers by supplying the hollow fiber membrane filtration water becomes open when the draining and backwashing unit comprising a reversing valve 11 which is opened when the backwash pump 10 and backwashing a membrane module 4 to the counter pressure washing, the primary side of the water of the hollow fiber membrane module 4 a drain valve 12, the primary side of the hollow fiber membrane module 4 compressed air Open to become an air supply unit including a compressor 14 which is a source of air washing valve 13 and the compressed air, an oxidizing agent oxidizing agent to the oxidizing agent reservoir 15 and the reverse 圧洗 purified water storing when supplied to the air cleaning an oxidant supply unit containing an oxidizing agent supply pump 16 for supplying a reducing agent supply unit containing a reducing agent supply pump 18 for supplying a reducing agent to the reducing agent reservoir 17 and the raw water storing reducing agent, the oxidizing agent a bypass line 19 which passed through the hollow fiber membrane module 4 and the washing water of the secondary side piping after back pressure washing with water containing a hollow fiber membrane module 4 and after back pressure washing with water containing an oxidizing agent bypass valve 20 is provided to be opened at the time of secondary pipe cleaning. Incidentally, the air supply unit may comprise a blower.

In the fresh water generator, the normal filtration process, is supplied to the primary side of the hollow fiber membrane module 4 raw water raw water supply valve 3 is stored in the raw water storage tank 1 in an open state by the raw water feed pump 2, pressure filtration is carried out in that the hollow fiber membrane module 4 of the filtering valve 6 to open. It is preferred to appropriately set according to the filtration time raw water quality and filtration flux, may be filtered continuously to reach a predetermined filtration pressure difference.

Membrane filtration water of the hollow fiber membrane module 4, after being stored temporarily in membrane filtered water storage tank 7 is pressurized by the booster pump 9 is supplied to the semipermeable membrane module 8, solutes such as salt has been removed and membrane filtered water, solutes, such as salt is separated into concentrated water.

The regular filtration direction to the hollow fiber membrane module 4 after filtration operation for a predetermined time an inverse pressure cleaned to backflow washing water from the opposite direction. This washing because it is being implemented with the continuous operation a semi-permeable membrane module 8, this period the mid permeable membrane module 8 shall use the filtered water that is stored in the membrane filtration water storage tank 7. Stop the raw water feed pump 2, a raw water supply valve 3, by closing the filtration valve 6, stop the filtration step of the hollow fiber membrane module 4, makes air bleed valve 5 and the backwash valve 11 is opened, backwashing pump 10 is performed by running. Here, the washing water, when the water containing an oxidizing agent, supplying an oxidant oxidant reservoir 15 with an oxidizing agent supply pump 16.

Back pressure cleaning of the hollow fiber membrane module is regularly carried out in the course of continuing the membrane filtration, the frequency is about once in normal 15 minutes to 120 minutes. The counter-pressure washing with wash water containing an oxidizing agent is may be applied to the back pressure cleaning each time, oxidant chemicals cost reduction and subsequent semi-permeable membrane module 8 to reduce the risk of leakage the reason, it is preferred to carry out at a frequency of about once to several times to one week to one day.

Two counter-pressure washing time previously described is not particularly limitation, preferably in the range of 5 to 120 seconds. Back pressure cleaning time of one is less than 5 seconds can not be obtained a sufficient washing effect, the operation efficiency of the hollow fiber membrane module exceeds 120 seconds is lower. Flux of the reverse pressure washing is not particularly limitation, is preferably at least 0.5 times the filtration flux. In the reverse flux of pressure washing 0.5 times less than the filtration flux, adhere to the film surface, it is difficult to sufficiently remove deposited an organic pollutants. Although preferred because better flux of the reverse pressure washing high becomes higher cleaning effect of the membrane is appropriately set within a range which does not cause damage such as cracks in the destruction or membrane of the membrane module vessel.

The oxidizing agent to be added to the wash water, but sodium and hydrogen peroxide or chloramine hypochlorite can be used, sodium hypochlorite is preferable from the viewpoint of ease of use and cost. If the concentration of the oxidizing agent may range from a few mg / L ~ several thousand mg / L when sodium hypochlorite, but to hold with wash water containing an oxidizing agent to the hollow fiber membrane module 4 is 50 mg / L ~ about 1000mg / L is preferred. This and that all cleaning effect will be consumed can not be sufficiently obtained while retaining with wash water containing an oxidizing agent in the hollow fiber membrane module 4 when the oxidizing agent concentration is too low, the concentration is too high the cost of processing waste water is because such a number.

Preferably the time to hold with wash water containing an oxidizing agent to the hollow fiber membrane module 4 is about 5 to 180 minutes, further more preferably about 10 minutes to 30 minutes. So the contact weak detergency time is short, a longer time to stop the apparatus too long, because the operating efficiency of the apparatus is lowered.

Further, if the fouling substance is deposited and accumulated on the membrane surface and in the pores, feeding the compressed air compressor 14 to the primary side of the hollow fiber membrane module 4 by the Soraaraiben 13 to open, to vibrate the membrane the air cleaning is preferably carried out at least part of the time held in the hollow fiber membrane filtration water containing an oxidizing agent to the above-the two counter-pressure cleaning being carried out or performed before, after, or hollow fiber membrane module 4 . Air supplied to the primary side of the hollow fiber membrane module 4 of the primary extruded water and the hollow fiber membrane module 4 is discharged from the system through the air bleed valve 5. In this case, it is preferable because the pressure of the compressed air is higher becomes higher cleaning effect of the membrane is appropriately set within a range where the film is not damaged.

Immediately after performing an inverse pressure cleaning of the hollow fiber membrane module 4 by water containing an oxidizing agent, the oxidizing agent remaining on the hollow fiber membrane module 4 and the secondary side in the pipe flows downstream of the semipermeable membrane module 8, oxide since there is a fear of causing a deterioration in the present invention, the step of filtering the raw water reducing agent is added in the membrane module. After back pressure cleaning and air cleaning is completed, Soraaraiben 13 is closed, drain valve 12 that is opened, it was suspended in the hollow fiber membrane module within 4 peeled from the membrane surface and in the pores draining step of fouling material is discharged out of the system is performed. After draining process is completed, drain valve 12 is closed, the raw water supply valve 3 is opened, the water supply step is performed raw water supply pump 2 and a reducing agent supply pump 18 is operating, the primary side of the hollow fiber membrane module 4 filled with water after becoming becomes air bleed valve 5 is closed, the bypass valve 20 is opened, it performs filtration while discharging from the bypass line 19 to the outside of the system. After filtration predetermined time, the reducing agent supply pump 18 is stopped, filtered valve 6 is opened, that the reversing valve 11 and the bypass valve 20 is closed, back to the filtration step, and repeats the foregoing described process.

The reducing agent used for neutralization of the oxidizing agent, it may be used sodium hydrogen sulfite, sodium sulfite, and inorganic reducing agents such as sodium thiosulfate. Organic reducing agents such as oxalic acid and ascorbic acid are not suitable for the present invention from a problem that is costly to the waste water treatment increases the drainage TOC concentration. The concentration of reducing agent necessary to be in the range of several mg / L ~ several thousand mg / L, the oxidizing agent remaining on the hollow fiber membrane module 4 and filtered side of the secondary side in the pipe for reducing neutralized and more preferably to 1 times to 5 times the theoretical concentration.

Water oxidizing agent is added, membrane filtration water of the hollow fiber membrane module 4, but may be a membrane filtration water or concentrated water of the semipermeable membrane module 8, water recovery the use of membrane filtration water semipermeable membrane module 8 the rate is decreased, since the oxidizing agent is consumed in a concentrated and used concentrated water organics, it is preferable to use a membrane filtration water of the hollow fiber membrane module 4.

Membrane filtration water water containing a reducing agent, without passed through the bypass line 19, but may also be water in the membrane filtration water storage tank 7, it is insufficient or reduced neutralization, backwash valve 11 a small amount of oxidizing agent remaining between the oxidizing agent supply pump 16, or a portion in the bypass line 19 that may leak into the secondary side piping of the hollow fiber membrane module 4 at the time of the next counter-pressure washing it is preferred that the whole water passage.

Although the bypass line 19 is preferably provided between the oxidizing agent supply pump 16 and backwashing pump 10, when the backwash pump 10 capable reverse rotation, be provided in the backwash pump 10 and the membrane filtration water storage tank 7 I do not care. The bypass line 19 may be connected to the membrane filtration water storage tank 7, but that the reduction neutralization is connected to the outside of the system discharge line in order to reduce the risk of leakage of insufficient oxidizing agent preferable.

Membrane filtration water of the water reducing agent is added in the raw water or the hollow fiber membrane module 4, but may be a membrane filtration water or concentrated water of the semipermeable membrane module 8, film of the hollow fiber membrane module 4 and a semi-permeable membrane module 8 using filtered water water recovery rate decreases, because the occurrence of clogging in concentrated organic or inorganic and is used to concentrate the semipermeable membrane module 8 is concerned, it is preferable to use a raw water.

The following Examples time filtering water containing a reducing agent, preferably carried out until the oxidizing agent on the secondary side in the pipe of the hollow fiber membrane module 4 within or hollow fiber membrane module 4 is reduced neutralized, for example, as an oxidizing agent when using sodium chlorite, it is preferable that free chlorine concentration in the bypass line 19 is carried out to the extent that the order of 0.1 m / L. The method of measuring the concentration of free chlorine, DPD method, current method, absorption spectroscopy and the like are used. Measurements appropriate water sampling, or to measure the concentration of free chlorine by the DPD method and current method, to measure the concentration of free chlorine by continuous automatic measurement device using absorption spectroscopy. These measurements, free chlorine concentration was monitored, it is preferable to determine and adjust the time for filtering the added water reducing agent.

As the hollow fiber membrane module 4 of the present invention, even such a non-pressure type membrane module as in FIG. 1, is immersed in the contained membrane immersion tank of the raw water either submerged membrane module to suction filtration with a pump or a siphon like I do not care. Also the case of a pressurized membrane module may be a pressure type in external pressure type, but it is preferable that the external pressure from the standpoint of ease of pretreatment.

The material of the porous film constituting the module is not particularly limited as long as the hollow fiber membrane of porous inorganic materials such as ceramics, polyethylene, polypropylene, polyacrylonitrile, ethylene - tetrafluoroethylene copolymer, polychloro , polytetrafluoroethylene, polyvinyl fluoride, tetrafluoroethylene - hexafluoropropylene copolymer, tetrafluoroethylene - perfluoroalkyl vinyl ether copolymer, chlorotrifluoroethylene - ethylene copolymer, polyvinylidene fluoride, polysulfones, cellulose acetate, polyvinyl alcohol, polyether sulfone, preferably as containing at least one member selected from the group consisting of vinyl chloride, from further film strength and in terms of chemical resistance poly Kka vinylidene (PVDF) are more preferable, and polyacrylonitrile is more preferable from the viewpoint that a strong high stain resistance hydrophilic. There is no particular limitation on the pore diameter of the hollow fiber membrane surfaces, without regard even microfiltration (MF) be a film ultrafiltration (UF) membrane, is conveniently selected in the range of 0.001 [mu] m ~ 10 [mu] m be able to.

The shape of the separation membrane is not particularly limited, hollow fiber membranes, flat membranes, tubular membranes, there is a monolithic film or the like, may be any.

Filtration system, dead-end filtration method, but may be either cross-flow filtration method, it is preferable that the total amount filtered from the viewpoint of energy consumption is small.

Examples of the filtration flow rate control method of the membrane filtration device, but not safely be also constant pressure filtration a constant flow filtration, it is a constant flow filtration in view of easy control of the production amount of water filtered water it is preferable.

The semipermeable membrane comprises a portion of the components of the separation liquid mixture, such as a solvent by transmitting a film having semipermeable which does not transmit other components, a nanofiltration membrane or a reverse osmosis membrane. Its The material cellulose acetate polymers, polyamides, polyesters, polyimides, polymer materials such as vinyl polymers are often used. Also the film structure has at least one surface dense layer of the membrane, a dense layer inside the membrane or an asymmetric membrane having a gradually larger pore diameter micropores toward the other surface, another on the dense layer of an asymmetric membrane etc. can be appropriately used a composite membrane having a very thin separation function layer formed of a material. The membrane form is a hollow fiber membrane, a flat membrane. The present invention, these membrane materials, it is both effective can be carried out regardless of the film structure and film form, typical examples of film, for example, cellulose acetate or polyamide asymmetrical membrane and polyamide-based, poly include a composite membrane having a separation function layer of urea, desalination amount, durability, in terms of salt rejection, cellulose acetate asymmetric membrane, it is preferable to use a composite film of polyamide.

Operating pressure of the semipermeable membrane module 8 is 0.1 MPa ~ 15 MPa, the type of supply water, are selectively used as appropriate, such as the operating method. In relatively low pressure in the case of low water penetration pressure, such as brackish water or ultrapure water and feed water, desalination or waste water treatment, when such recovery of useful substances are used in relatively high pressure.

Further, in the present invention, semi-permeable membrane module 8 with a nanofiltration membrane or a reverse osmosis membrane, modules of matches in 1 to several pressure vessels said semipermeable membrane element but of course, this module but also including those arranged in a plurality of parallel. Combination, number, sequence may be carried out arbitrarily depending on the purpose. Note that the semi-permeable membrane elements, wherein is obtained by form of to actually use the semipermeable membrane, flat membrane is spiral, tubular, as a plate-and-frame type element, also hollow fiber membranes can be used by incorporating into the case on a bundle, the present invention is not also being dependent on the form of semi-permeable membrane elements.

By way of specific examples below illustrate the invention but are not intended to be limited by the present invention these examples.

<Example 1>
As shown in FIG. 1, the hollow fiber membrane module 4 by Toray Industries Co., Ltd. molecular weight cutoff 150,000 Da pressure type membrane module in polyvinylidene fluoride hollow fiber UF membrane membrane area of 72m 2 of (HFU-2020 ) using one, by opening the filtration valve 6 and the raw water supply valve 3, by operating the raw water supply pump 2, turbidity 4 degrees, TOC2mg / L, the salt concentration of 3.5% seawater filtration flux 3m / and dead-end filtration in d. Further, (TM820-400) Toray Co. reverse osmosis membrane element in a semi-permeable membrane module 8 4 using a membrane filtration flow rate 60 m 3 / d, concentrated water flow rate 120 m 3 / d, filtered through a recovery rate of 33% did.

After the hollow fiber membrane module 4 is filtered 30 minutes, close the filtration valve 6 and the raw water supply valve 3, on stopping the raw water supply pump 2, open the backwash valve 11 and Soraaraiben 13 and the air vent valve 5, running the backwash pump 10, and at the same time carried out for 1 minute air cleaning supplies air in flux 3m / d back pressure cleaning and film downward from 100L / min modules. Then, close the backwash valve 11 and Soraaraiben 13, on stopping backwash pump 10, opens the drain valve 12 was totally drained water of the hollow fiber membrane module 4 to the outside of the system. Thereafter, by opening the filtration valve 6 and the raw water supply valve 3, by operating the raw water supply pump 2, after the supply of raw water to the hollow fiber membrane module 4, to close the air bleed valve 5 returns to the filtration process, previously described It went by repeating the process.

It was also carried back pressure cleaning using wash water with the addition of sodium hypochlorite four times daily oxidant storage tank 15 to membrane filtration water of the hollow fiber membrane module 4. Open the backwash valve 11 and Soraaraiben 13 and the air vent valve 5, the backwash pump 10, and operating the oxidant supply pump 16, primary and backpressure cleaning flux 3m / d hollow fiber membrane module 4 It was simultaneously carried out for 1 minute air cleaning supplies air at 100L / min to the side. The chlorine concentration of the reverse 圧洗 in clean water at this time was 300mg / L. Next, the backwash pump 10, and stops the oxidant supply pump 16, a hollow fiber membrane module 4 and held for 20 minutes at a chlorine concentration of 300 mg / L. Thereafter, by opening the drain valve 12 it was totally drained water of the hollow fiber membrane module 4 to the outside of the system. Then open the raw water supply valve 3 and the bypass valve 20, in operation the raw water feed pump 2 and a reducing agent supply pump 18, after the supply of raw water sodium bisulfite was added to the hollow fiber membrane module 4, an air close the vent valve 5, filtered while passing water was performed for 1 minute in the bypass line 19. Thereafter, by closing the raw water supply valve 3, a raw water feed pump 2 and a reducing agent supply pump 18 is stopped, by opening the air bleed valve 5 and the drain valve 12, totally drained water of the hollow fiber membrane module 4 to the outside of the system did. Such a reducing agent rinsing step was performed three times. Also, the sodium bisulfite concentration in the raw water at this time was 300 mg / L. Thereafter, the reducing agent supply pump 18 is stopped, by opening the filtration valve 6 closes the reversing valve 11 and the bypass valve 20, back to the filtration step was repeated foregoing described steps.

As a result, the water recovery rate of the hollow fiber membrane module 4 92.7% (Production water 162.1m 3 / day), filtered differential pressure to 60kPa immediately after the start of operation, even two months remained the 60 ~ 70 kPa, I was able to stable operation. Further, salt rejection of a semipermeable membrane module 8 to 99.7% immediately after the start of operation, and has remained stable 99.6% after 2 months.

(Comparative Example 1)
After backwash by wash water with the addition of sodium hypochlorite, except that was not carried out the addition of sodium bisulfite to the raw water was exactly the same as in Example 1.

As a result, the water recovery rate of the hollow fiber membrane module 4 92.7% (Production water 162.1m 3 / day), filtered differential pressure to 60kPa immediately after the start of operation, even two months remained the 60 ~ 70 kPa, I was able to stable operation. However, salt rejection of the reverse osmosis membrane module 8 to 99.7% immediately after the start of operation by oxidative degradation, after two months was reduced to 92.3%. Compared to Example 1, water recovery and productivity water of the hollow fiber membrane module 4 are equivalent, the salt rejection of a semipermeable membrane module 8 was reduced.

(Comparative Example 2)
Instead of carrying out the filtration while passed through the raw water sodium bisulfite was added to the bypass line 19, the counter-pressure washing with cleaning water prepared by adding sodium bisulfite to a membrane filtration water of the hollow fiber membrane module 4 1 minutes, except that it has carried out to exactly the same as in example 1.

As a result, the water recovery rate of the hollow fiber membrane module 4 92.6% (Production water 159.7m 3 / day), filtered differential pressure to 60kPa immediately after the start of operation, even two months remained the 60 ~ 70 kPa, I was able to stable operation. To 99.7% after desalting rate starts operation of the reverse osmosis membrane module 8, a stable 99.6% after 2 months. Compared with Example 1, but the salt rejection of a semipermeable membrane modules 8 can be stably operated without reducing the water recovery rate of the hollow fiber membrane module 4 was reduced.

The present invention has been described with reference to also specific embodiments in detail, it is possible to make various changes and modifications without departing from the spirit and scope of the invention will be apparent to those skilled in the art.
The present application is based on Japanese Patent Application 2010-045037, filed on March 2, 2010, the contents of which are incorporated herein by reference.

According to the cleaning method of the membrane module of the present invention, the membrane separation apparatus for membrane filtration in a porous membrane module raw water, to prevent leakage of oxidant to the subsequent stage, high water recovery and productivity water is effectively it is possible to provide a method of cleaning a porous membrane module.

1 raw water storage tank 2 raw water supply pump 3 the raw water supply valve 4 hollow fiber membrane module 5 air bleed valve 6 filtration valve 7 membrane filtration water storage tank 8 semipermeable membrane module 9 booster pump 10 backwash pump 11 backwash valve 12 drain valve 13 Soraaraiben 14 compressor 15 oxidizing agent reservoir 16 oxidizing agent supply pump 17 reducing agent reservoir 18 reducing agent supply pump 19 a bypass line 20 bypassing valves

Claims (12)

  1. After performing back pressure washing with water containing an oxidizing agent, it comprises filtering the water containing a reducing agent by a porous membrane module, a method of cleaning a porous membrane module.
  2. The method of cleaning a porous membrane module according to claim 1, comprising discharging at least a portion of the membrane filtration water of water containing a reducing agent, to the outside of the system from the bypass line provided on the back pressure cleaning line.
  3. At least part of the membrane filtration water of water containing a reducing agent, a bypass line provided on the back pressure cleaning line comprises water to membrane filtration water storage tank, a porous membrane module according to claim 1 or 2 cleaning method.
  4. Before or after filtering the water containing a reducing agent, which comprises counter-pressure washing a porous membrane module with a membrane filtration water, a porous membrane module cleaning method according to any one of claims 1 to 3.
  5. After performing back pressure washing with water containing an oxidizing agent, it comprises holding a predetermined time water containing oxidizing agent to the porous membrane module, according to any one of claims 1 to 4, the method of cleaning a porous membrane module.
  6. During implementation of the counter pressure washing with water containing an oxidizing agent, before the implementation, after implementation, and to carry out the air cleaning at least part of the time holding the water containing the oxidizing agent to the porous membrane in the module including a method of cleaning a porous membrane module according to any one of claims 1 to 5.
  7. Comprising porous membrane at least a portion of the membrane filtration water obtained by filtration using a module is filtered by a semipermeable membrane, the method of cleaning a porous membrane module according to any one of claims 1 to 6, .
  8. And a porous membrane module,
    From the secondary side and the back pressure cleaning unit for supplying the primary side of the porous membrane module membrane filtration water in the porous membrane module,
    And the porous membrane module of the membrane oxidant supply unit for supplying an oxidizing agent from the secondary side to the line for supplying the primary side of the filtered water the porous membrane module,
    A reducing agent supply unit for supplying a reducing agent to the primary side of the porous membrane module,
    Desalination device that includes a.
  9. Comprising said porous membrane module of the secondary line and the outside of the system for supplying the membrane filtration water on the primary side from the side discharge line and connected to the bypass line, the fresh water generator according to claim 8.
  10. Comprising said porous membrane bypass line connected line and the membrane filtration water reservoir supplying the membrane filtration water on the primary side from the secondary side of the module, fresh water generator according to claim 8 or 9.
  11. Porous membrane further comprises an air supply unit for supplying gas to the primary side of the module, fresh water generator according to any one of claims 8-10.
  12. Including a semipermeable membrane modules for filtering at least a portion of the membrane filtration water obtained by filtration using a porous membrane module, fresh water generator according to any one of claims 8-11.
PCT/JP2011/054771 2010-03-02 2011-03-02 Method for washing porous membrane module, and fresh water generator WO2011108589A1 (en)

Priority Applications (2)

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JP2010045037 2010-03-02

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9333464B1 (en) 2014-10-22 2016-05-10 Koch Membrane Systems, Inc. Membrane module system with bundle enclosures and pulsed aeration and method of operation
USD779631S1 (en) 2015-08-10 2017-02-21 Koch Membrane Systems, Inc. Gasification device
JP2017100101A (en) * 2015-12-04 2017-06-08 住友電気工業株式会社 Method for cleaning filter film

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001079367A (en) * 1999-09-14 2001-03-27 Hitachi Plant Eng & Constr Co Ltd Membrane separation method and device thereof
JP2001232161A (en) * 2000-02-22 2001-08-28 Kurita Water Ind Ltd Method for cleaning membrane module
JP2005074386A (en) * 2003-09-03 2005-03-24 Toray Ind Inc Method for preparing clear water
JP2006314973A (en) * 2005-05-16 2006-11-24 Fuji Electric Holdings Co Ltd Washing method of filter membrane
JP2009006209A (en) * 2007-06-26 2009-01-15 Toray Ind Inc Cleaning method of hollow fiber membrane module

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001079367A (en) * 1999-09-14 2001-03-27 Hitachi Plant Eng & Constr Co Ltd Membrane separation method and device thereof
JP2001232161A (en) * 2000-02-22 2001-08-28 Kurita Water Ind Ltd Method for cleaning membrane module
JP2005074386A (en) * 2003-09-03 2005-03-24 Toray Ind Inc Method for preparing clear water
JP2006314973A (en) * 2005-05-16 2006-11-24 Fuji Electric Holdings Co Ltd Washing method of filter membrane
JP2009006209A (en) * 2007-06-26 2009-01-15 Toray Ind Inc Cleaning method of hollow fiber membrane module

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9333464B1 (en) 2014-10-22 2016-05-10 Koch Membrane Systems, Inc. Membrane module system with bundle enclosures and pulsed aeration and method of operation
US9956530B2 (en) 2014-10-22 2018-05-01 Koch Membrane Systems, Inc. Membrane module system with bundle enclosures and pulsed aeration and method of operation
USD779631S1 (en) 2015-08-10 2017-02-21 Koch Membrane Systems, Inc. Gasification device
USD779632S1 (en) 2015-08-10 2017-02-21 Koch Membrane Systems, Inc. Bundle body
JP2017100101A (en) * 2015-12-04 2017-06-08 住友電気工業株式会社 Method for cleaning filter film

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