BULK LIQUID MEMBRANE WITH POROUS PARTITION MEMBRANE

Studies have been made of mass-transfer characteristics of a novel operation mode of the liquid membrane. In this operation, feed and recovery sides were partitioned by a hydrophobic porous membrane, and a membrane solution was forced to flow with a feed or recovery solution within each flow channel. The membrane solution moves through the pores of the porous membrane freely, and the solute extracted within the feed-side channel was transferred across the porous partition membrane by the bulk motion of the membrane solution as well as by diffusion, i.e., the organic phase acts as a bulk liquid membrane. By decreasing the depth of flow channels, a large specific interfacial area can be obtained, which becomes an advantage in practical use. It was shown that this operation mode has possibilities of fast separation and concentration in comparison with operation in a supported liquid membrane. To evaluate the contribution of bulk motion or the membrane solution across the porous membrane, a transfer coefficient of membrane based on a model for the present mode is introduced and correlated with organic phase velocity. Experimental results for circulating membrane solution between the feed-side and the recovery-side channels suggest that efficient concentration of solute can be achieved in this operation mode.