MEMBRANE SEPARATION METHOD

PROBLEM TO BE SOLVED: To provide a membrane separation method which enable the sufficient removal of soluble manganese with a simple apparatus configuration and suppression of an increase in membrane pressure difference even if membrane separation treatment is carried out in a high recovery rate. SOLUTION: The membrane separation method comprises an oxidation deposition process of subjecting soluble manganese in water to be treated to oxidation deposition by loading water containing soluble manganese with an oxidant under presence of a manganese dioxide particle, a membrane separation step of obtaining membrane permeate as treated water by passing water containing the manganese dioxide particle from the oxidation deposition step through a filtration membrane, and recirculating at least a part of cleaning drainage from the membrane separation step to the oxidation deposition step by pressure gas/clean water and also discharging at least a part of the remnant outside a system, wherein the recovery rate expressed by 100×(Q-C)/Q (%) is 99% or larger when the flow rare of permeate is Q and the flow rare of cleaning drainage to be discharged outside the system is C. COPYRIGHT: (C)2008,JPO&INPIT