Abstract: A hydrophilized membrane of a porous hydrophobic material having micropores each defined by a surface at least part of which is coated with a hydrophilizing agent which is solid at about 20.degree. C. and substantially insoluble in water. The hydrophilizing agent is preferably selected from monofatty acid esters of propylene glycol. Also disclosed are processes for hydrophilizing such porous hydrophobic membranes.

Abstract: A hydrophilized membrane of a porous hydrophobic material having micropores each defined by a surface at least part of which is coated with a hydrophilizing agent which is solid at about 20.degree. C. and substantially insoluble in water. The hydrophilizing agent is preferably selected from monofatty acid esters of propylene glycol. Also disclosed are processes for hydrophilizing such porous hydrophobic membranes.

Abstract: A hollow-fiber filtering module includes a casing having an open end and an inlet for introducing water to be treated thereinto. A bundle of hollow fibers is mounted within the casing, each of the hollow fibers having an open end. A fastening member sealingly joins the open ends of the hollow fibers to the open end of the casing in sealing relation thereto, the open ends of the hollow fibers opening to the exterior of the casing. Part of the hollow fibers are made of a microporous membrane having a portion of a hydrophobic nature, and the other hollow fibers are hydrophilic microporous membranes. Gas introduced into the filtering module can easily permeate the hydrophobic portions of the hollow fibers and is discharged through the bores of the hollow fibers from their open ends together with the filtered water. There is also disclosed a water purification device employing such a hollow-fiber filtering module.