酢酸セルロース製逆浸透膜による放射性核種の除去 （ＩＩ） 濃度分極層の生成消滅に関する実験的研究

Abstract

Experiments were performed on the removal of radionuclides from radioactive liquid waste by reverse osmosis using asymmetric cellulose acetate membranes. In previous papers, we reported such removal properties as the dependence on solute concentration and the influence of co-existing material.In this paper we performed experiments on some separation properties, especially on the formation and the disappearance of concentration polarization layer of membrane surface. These experiments are necessary for the theoretical explanation of findings shown in previous papers.Concentration polarization layer is formed on the surface of the membrane, when pressurized feed solution is not stirred during reverse osmosis operation. This layer grows with elapsed time and reaches the equilibrium. The thickness of this concentration polarization layer and solute concentrations in this layer are calculated by a simple model.The formation and disappearance of this layer are experimented with intermittent stirring. The influence of intensity of stirring on the formation of concentration polarization layer is observed. These are important information on property of membrane for removing solute by reverse osmosis.