METHOD AND APPARATUS FOR TREATING TURBID WATER

摘要

PROBLEM TO BE SOLVED: To effectively treat turbid water simply and inexpensively. SOLUTION: Turbid water with BOD of 50 mg/L or less and SS of 100 mg/L or more is subjected to cross flow filtering under an intermembranous pressure of 30 kPa or less by a separation membrane unit 5 using a nonwoven fabric membrane. A sedimentation tank for sedimenting and removing coarse particles of turbid water may be provided on the upstream side of the separation membrane unit for treating turbid water. Further, the separation membrane unit is constituted of nonwoven fabric membrane elements mutually separated to be opposed to each other and a treated water tank 6 for storing the filtered water from the separation membrane unit and a backwashing water tank 8 introducing a washing soln. or a chemical soln. to backwash the separation membrane unit may be equipped.