MEMBRANE SEPARATION DEVICE, AND CIRCULATED WATER UTILIZATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a membrane separation device in which life of a separation membrane element can be prolonged by suppressing the occurrence of unbalance in clogging of a separation membrane between on one end side of the membrane separation element and the other end side thereof.SOLUTION: A membrane separation device 18 includes: a separation membrane element 20; a first flow path 27 which can supply treatment target water from one end of the separation membrane element to a treatment target water flow path 41; a second flow path 28 which can supply the treatment target water from the other end to the treatment target water flow path; switching means 32 which can switch supply destination of the treatment target water between the first flow path and the second flow path; and control means 100. The control means controls the switching means to switch between a first operation mode in which permeated water is taken from a water collecting tube by supplying treatment target water to the treatment target water flow path from one end of the separation membrane element via the first flow path, and a second operation mode in which permeated water is taken from the water collecting tube by supplying treatment target water to the treatment target water flow path from the other end of the separation membrane element via the second flow path.