| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a flushing cleaning method which can peel and disperse suspended matters accumulated at the upstream side in an external pressure type membrane module, particularly in a module lower part, effectively, without degrading a recovery rate.SOLUTION: For a vertical pressurization-type hollow fiber membrane module including a hollow tubular housing and a hollow fiber membrane contained in the housing, from an upstream side inlet different from an inlet in a membrane filtration process, a flushing cleaning step introducing flushing feeding water using either of water to be treated or wash water having a suspended solid concentration not more than that of the water to be treated, with a flow rate which is not less than an inflow discharge of the water to be treated in the membrane filtration process.</p> |
