PREVENTING REVERSE OSMOSIS MEMBRANE FROM CONTAMINATION WITH LIVING THING

摘要

PURPOSE: To suppress growth and reproduction of microorganisms on a device after dechlorination by adding chloramine in an enough amt. to sterilize =99 % of bacteria present before dechlorination to a liquid process flow. CONSTITUTION: Chloramine in an enough amt. to sterilize at least 99% of microorganisms in a liquid process flow is continuously added to the process flow. The liquid process flow in this state is introduced into at least one reverse osmosis module containing a core member having a semipermeable membrane which is positioned to allow the liquid to permeate and to form a permeate flow. Thereby, growth and reproduction of microorganisms in the liquid process flow and on the membrane can be suppressed, and then a sufficient reducing agent is added to remove the chloramine. The chloramine is preferably in-situ produced by first adding NH3 and then adding chlorine.