HOLLOW-FIBER MEMBRANE FOR IMMERSION FILTRATION, HOLLOW-FIBER MEMBRANE MODULE FOR IMMERSION FILTRATION EMPLOYING THE SAME, APPARATUS FOR IMMERSION FILTRATION, AND METHOD OF IMMERSION FILTRATION

摘要

A hollow-fiber membrane for immersion filtration which has one or more protrudent parts on the outer surface; and a hollow-fiber membrane module for immersion filtration which is produced by bonding and fixing two or more such hollow-fiber membranes to a housing. Even when membrane filtration in a high-concentration suspension is continued, the effect of physically cleaning the membranes or module by air bubbling is high and an excess deposit is less apt to accumulate on the membrane surface. Consequently, the membranes and module suffer no decrease in water permeability during the continuation of operation.