Title:
WATER PRODUCTION METHOD
Document Type and Number:
WIPO Patent Application WO/2014/034845
Kind Code:
A1
Abstract:
The present invention addresses the problem of providing a method for cleaning a separation membrane, the method making it possible to prevent an increase in differential pressure while reducing the amounts of a chemical and rinse water necessary for cleaning the membrane and while inhibiting the inside of the separation membrane module from increasing in pH through the cleaning.
The method is a water production method which comprises: a step for yielding water to be membrane-filtered, by treating raw water; a filtration step in which the water to be membrane-filtered is filtered with a separation membrane module having a separation membrane to thereby yield membrane-filtered water; a back-pressure washing step in which the substances that were filtered out and that clogged the separation membrane in the filtration step are removed using washing water; and a drainage step in which the washing wastewater used for washing in the back-pressure washing step is drained. The step for yielding water to be membrane-filtered comprises a coagulation step in which a first pH regulator and a cationic coagulant are added to the raw water to coagulate substances which are contained in the raw water and are to be filtered out, thereby producing pretreated water. The pH of the water to be membrane-filtered and the pH of the washing water are regulated to values satisfying specific requirements.
Inventors:
KOBAYASHI KENTARO (JP)
TAKABATAKE HIROO (JP)
TAKABATAKE HIROO (JP)
Application Number:
PCT/JP2013/073318
Publication Date:
March 06, 2014
Filing Date:
August 30, 2013
Export Citation:
Assignee:
TORAY INDUSTRIES (JP)
International Classes:
C02F1/44; B01D65/02; B01D65/06; C02F1/52
Foreign References:
| JP2007245078A | 2007-09-27 | |||
| JP2011110439A | 2011-06-09 | |||
| JP2001276844A | 2001-10-09 | |||
| JP2005288442A | 2005-10-20 | |||
| JPH01228588A | 1989-09-12 |
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