Effective Methods of Washing and Removing a Dynamic Ultrafiltration Membrane

Abstract

Practical methods of washing and removing the dynamic ultrafiltration membrane developed by the authors were experimentally studied. The membrane itself was of dual-layer type, made from alumina sol and colloidal silica. The material of the membrane support was porous ceramics made of sintered alumina and silica.
The membrane, after its use in concentrating aqueous gelatin solutions, was successfully washed by passing hot water through it without appreciable deterioration in its separation ability. Then, by passing an aqueous hydroxide solution through it, the membrane layer was dissolved and removed from the support. However, because of a small amount of silica eluted from the ceramic support by the hot water and the alkaline solution, the mechanical strength of the support was lowered.