Transport of Th(IV) and U(VI) through barium silico-phosphate composite membrane using electric field

The present paper describes the preparation of a novel barium silico-phosphate filter paper supported membrane. It is based on precipitation reaction of barium silico-phosphate on the outer surface and in the interstices of a filter paper by means of electrodialysis. The main physical and electrical properties of the membrane are given and its electrodialysis behaviour is assessed for Th(IV) and U(VI). The transport of Th(IV) in presence of U(VI) was studied. The cationic fluxes of Th(IV) and U(VI) were found to be 1.2 x 10-8 and 6.5 x 10-9 g eq cm-2 s-1, respectively. Transport of Th(IV) and U(VI) in presence of EDTA was investigated. The cationic flux of U(VI) is found to be 9.8 x 10-9 g eq cm-2 s-1 at a current density of 25 mA/cm2. A comparative study on the electro osmotic effect was carried out using the developed membrane and commercially available Nafion membranes. In this context, different parameters like current density, electrolyte concentration, etc. were investigated. The electro-osmotic permeability coefficient, De, of Th(IV) through barium silico-phosphate and Nafion membranes were 6.9 x 10-2 and 1.0 x 10-2 cm3/As, respectively. It can be concluded that inorganic membranes have very marked electro-osmotic properties unlike their organic counterparts. (orig.)