FRESH WATER TREATMENT APPARATUS EQUIPPED WITH REVERSE OSMOSIS MEMBRANE AND OPERATION METHOD OF FRESH WATER TREATMENT APPARATUS EQUIPPED WITH REVERSE OSMOSIS MEMBRANE

To provide a fresh water treatment apparatus capable of suppressing reverse osmosis membrane blockage and stably operating while keeping a high recovery rate.SOLUTION: A fresh water treatment apparatus has: a reverse osmosis membrane; a fresh water supply pipe for supplying fresh water to the reverse osmosis membrane; a permeate pipe for transferring the permeated water of the reverse osmosis membrane; a circulating water pipe for circulating at least a part of the concentrated water of the reverse osmosis membrane to the fresh water supply pipe; and a drain pipe for draining at least part of the concentrated water of the reverse osmosis membrane. The circulating water pipe has a circulating water pressure regulating valve capable of adjusting the amount of concentrated water to be circulated, and the drain pipe has a drain pressure regulating valve capable of adjusting the amount of concentrated water to be drained.SELECTED DRAWING: Figure 1 【課題】逆浸透膜閉塞を抑制できるとともに、安定して高い回収率を維持して運転できる、淡水の処理装置を提供する。【解決手段】逆浸透膜、該逆浸透膜に淡水を供給する淡水供給配管、該逆浸透膜の透過水を移送する透過水配管、該逆浸透膜の濃縮水の少なくとも一部を該淡水供給配管に循環する循環水配管、及び該逆浸透膜の濃縮水の少なくとも一部を排水する排水配管、を備え、前記循環水配管は、循環する濃縮水の量を調整し得る循環水調圧弁を有し、前記排水配管は、排水する濃縮水の量を調整し得る排水調圧弁を有する、淡水の処理装置。【選択図】 図１