JP2006272136A5

JP2006272136A5 -

Info

Publication number: JP2006272136A5
Application number: JP2005094335A
Authority: JP
Filing date: 2005-03-29
Publication date: 2009-08-06
Anticipated expiration: 2025-03-29

Description

次に、逆浸透膜モジュールで得られた濃縮水の少なくとも一部を精密ろ過膜モジュールまたは限外ろ過膜モジュールの洗浄水とする洗浄方法について説明する。この洗浄方法も、逆浸透膜モジュールの運転を継続しつつ実施するものであるため、バルブＶ３、Ｖ６は開のままである。洗浄は、バルブＶ４、Ｖ７を閉とし、ポンプ４を停止してからバルブＶ１、Ｖ２を閉とした後、バルブＶ５を開とし、逆浸透膜モジュールで得られた濃縮水の少なくとも一部を濃縮水返送手段１２を通して精密ろ過膜モジュールまたは限外ろ過膜モジュールへ逆流させることで行う。 Next, a cleaning method will be described in which at least a part of the concentrated water obtained by the reverse osmosis membrane module is used as cleaning water for the microfiltration membrane module or the ultrafiltration membrane module. Since this washing method is also performed while continuing the operation of the reverse osmosis membrane module, the valves V3 and V6 remain open. For cleaning, the valves V4 and V7 are closed, the pump 4 is stopped, the valves V1 and V2 are closed, the valve V5 is opened, and at least a part of the concentrated water obtained by the reverse osmosis membrane module is concentrated. It carried out by causing reverse flow into the microfiltration membrane module or ultrafiltration membrane module through the water return feed unit 12.

Claims

In the membrane separation method of treating raw water containing salt with a microfiltration membrane module or an ultrafiltration membrane module, reverse osmosis treatment with a reverse osmosis membrane module, the microfiltration membrane module or ultrafiltration The treated water obtained by treating with the membrane module is used as washing water, and the backwashing of the microfiltration membrane used in the microfiltration membrane module or the ultrafiltration membrane used in the ultrafiltration membrane module is periodically performed. The microfiltration membrane or the ultrafiltration membrane is washed in the range of once a month to 10 times a day using at least a part of the permeated water obtained by the reverse osmosis membrane module as washing water. A membrane separation method.

Cleaning means A for cleaning the microfiltration membrane used in the microfiltration membrane module or the ultrafiltration membrane used in the ultrafiltration membrane module with the concentrated water obtained by the reverse osmosis membrane module, and the reverse osmosis membrane module A cleaning means B for cleaning the microfiltration membrane used in the microfiltration membrane module or the ultrafiltration membrane used in the ultrafiltration membrane module with the permeated water obtained in step 1 above, and the cleaning means A next to the cleaning means A The membrane separation method according to claim 1, wherein the membrane separation method is performed in the order of B or in the order of the cleaning means A after the cleaning means B.

Membrane separation method according to claim 1 or 2, wherein the pH of the permeate and / or retentate obtained in the reverse osmosis membrane module is 5 or less.

A device for membrane separation treatment of raw water containing salt, reverse osmosis of microfiltration membrane module or ultrafiltration membrane module and treated water obtained by the microfiltration membrane module or ultrafiltration membrane module The reverse osmosis membrane module to be treated and the treated water obtained by the microfiltration membrane module or the ultrafiltration membrane module are used as washing water, to the microfiltration membrane used in the microfiltration membrane module or the ultrafiltration membrane module Means for returning the ultrafiltration membrane used for backflow cleaning, and means for returning at least part of the permeated water obtained by the reverse osmosis membrane module as washing water for the microfiltration membrane or the ultrafiltration membrane And a membrane separation device.

5. The membrane separation apparatus according to claim 4, further comprising an acid addition device for adjusting the pH of the water supplied to the reverse osmosis membrane module to 5 or less.