METHOD FOR FILTERING CHARGEABLE SUSPENDED SOLID

摘要

PURPOSE:To enhance effect for maintaining high membrane permeation flux by providing the electrodes to both sides of a filter membrane and imparting an electric field to the filter membrane and also periodically stopping pressurization in the case of pressure-filtering fluid incorporating charged fine particles. CONSTITUTION:In the case of filtering raw liquid incorporating e.g., polystyrene latex particles having negative charge by a cross current filter, a counter electrode 7 is provided to the raw liquid side of a filter membrane 6 while keeping a constant interval apart from the filter membrane 6 and an electric field is imparted with a DC electric source 8 so that an electrode (oblique lined) provided adherently to the filter membrane 6 in the permeation side thereof may serve as a cathode. The feed pump 2 of raw liquid is periodically stopped and feed of raw liquid to the membrane is periodically stopped and also raw liquid is filtered while imparting an electric field and thereby both deposition of the particles on the surface of the membrane of the raw liquid side and sticking of the particles into the fine holes of the filter membrane can be inhibited by utilizing electric resiliency generated between the filter membrane and the charged particles.