Separating membrane preservation liquid and separating membrane module

TLDR: In this paper, a separating membrane preservation liquid in the wet state is used for preserving a separation membrane for separating permeated water by filling a raw water used in the fields of food industry, medical care, purification of water and the like when being not used in prepared from a solution containing sodium sulfite.

Abstract: PROBLEM TO BE SOLVED: To keep the high sterilization effect for a long period of time and prevent the deterioration of a separating membrane and the permeation performance thereof by preparing a separating membrane preservation liquid from a solution containing sodium bisulfite. SOLUTION: A separating membrane preservation liquid in the wet state used for preserving a separating membrane for separating permeated water by filling a raw water used in the fields of food industry, medical care, purification of water and the like when being not used in prepared from a solution containing sodium sulfite. The sodium sulfite is provided with the high sterilization effect for aerobic bacteria, free from toxicity, keeping its sterilization effect for a long time and not oxidizing a polymer nor deteriorating the separating membrane, by which the permeation performance is not lowered. The concentration of the sodium bisulfite to be used is preferably in the range of 0.01-5%, more preferably 0.02-0.05%. Although no particular restrictions are applied for a solvent, water is best for the purpose in consideration of operation properties, and among other things, sterilized water is preferred most.