METHOD OF CLEANING FILTER MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a method of cleaning a filter membrane which requires little need of carrying out off-line cleaning with a chemical or chemical cleaning causing a decrease of the operation rate of the equipment, is based on chemical immersion employing sodium hypochlorite and citric acid and achieves a reduction of running costs without a decrease of the recovery rate. SOLUTION: The method of cleaning a filter membrane has a contact step of bringing a filter membrane into contact with a chemical and a rinse step of removing the chemical from the filter membrane. The method is characterized by measuring the concentration of the residue of the chemical in the solution in terms of the electric conductivity and shifting to the next step when the conductivity reaches a specified value. COPYRIGHT: (C)2007,JPO&INPIT