Membrane Separation Technology In Ultrafine Particle Suspended In A Liquid Solid-liquid Separation

This study focuses on the solid-liquid separation technology applied to high concentration superfine particles suspension. Study is also carried on the new application of membrane separation technology. The research of membrane separation processes is carried out according to the different kinds of superfine particles contained in the suspension and the different particle size distribution(PSD).Two types of micro-filtration——Cross-flow micro-filtration and Dead-end micro-filtration; Three processes of solid-liquid separation of different suspension——mono-dispersed, multi-dispersed and suspension with different kind of superfine particles are studied. Two type of membrane module are carried into application——tubular polymeric membrane and hollow fiber membrane filter.The effect of the operating conditions——the operation time, temperature, cross-flow velocity (CFV), transmembrane pressure (TMP) and feed concentration (C_F) on the membrane separation are investigated. The internal and surface fouling of membrane are estimated to provide a more complete understanding of the process of particle deposition and layer formation. Cross-flow filtration also developed as a new method of wet classification of multi-dispersed superfine particles. Further more, this paper discusses strategies to reduce energy usage in low pressure membrane processes. Studies on the role of air bubbling and air back washing to control fouling in submerged membrane systems are described. And the jointly usage of the hollow fiber membrane and the polymer micro-porous filter are discussed.