SEPARATION MEMBRANE, SEPARATION MEMBRANE ELEMENT, MEMBRANE FILTRATION APPARATUS AND METHOD OF TREATING SEWAGE AND WASTE WATER USING THEM

摘要

PROBLEM TO BE SOLVED: To provide a separation membrane never allowing bacteria, e. g. Esherichia coli, to slip into permeated water even immediately after starting of operation and giving quite safe permeated water. SOLUTION: The separation membrane consists of a filter medium 1 having an average pore diameter d1avand the maximum pore diameter d1maxand filter medium 2 having an average pore diameter d2avand the maximum pore diameter d2max, where the media 1 and 2 meet the conditions: (1) d1avsmaller than d2avand (2) d1maxlarger than d2max. COPYRIGHT: (C)2006,JPO&NCIPI