| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for cleaning a membrane module, by which deterioration in microbial activity in activated sludge in a reaction tank due to cleaning liquid chemicals can be suppressed, even if inline cleaning is performed.SOLUTION: The method for cleaning a membrane module is a cleaning method for an immersion type membrane separation device 1 immersed in a reaction tank T for storing water to be treated containing microorganism. The immersion type membrane separation device 1 includes a filtration membrane 7 for filtering the water to be treated, an external pressure filtration type membrane module 3 having a flat pre-filter 15 covering the filtration membrane 7, and a cleaning device 13 for flowing cleaning liquid chemicals from the filtrate water side of the membrane module 3 toward the side of the water to be treated. The cleaning method of the immersion type membrane separation device 1 includes a step of flowing the cleaning liquid chemicals from the cleaning device 13 toward the membrane module 3. In the step of flowing the cleaning liquid chemicals, the quantity of the cleaning liquid chemicals is adjusted so that the cleaning liquid chemicals from the cleaning device 13 may not leak out of the flat pre-filter 15. |
