Method for recovering efficiency of semipermeable membrane.

摘要

A method for recovering the efficiency of a semipermeable membrane which comprises treating said semipermeable membrane which has an active layer substantially consisting of a polymeric material having bond units containing a bond expressed by <CHEM> in the polymeric chain with at least one kind of organic solvent, or its aqueous solution, selected from a group of lower aliphatic alcohol, lower aliphatic ketone and lower aliphatic ester when the water flux efficiency of the semipermeable membrane is decreased due to the compaction which results from the reverse osmosis operation conducted under high temperature and/or high pressure.