Hiroyoshi Inoue

Removal of sodium ion from bile acid solution using diffusional dialysis with cation exchange membrane

The behavior of sodium ions passing through a CM1 cation exchange membrane was studied with electroconductive and diffusional membrane permeabilities based on nonequilibrium thermodynamics to remove sodium ion from bile acid solution. These membrane permeabilities of sodium ion in order of amplitude showed sodium chloride>sodiumtaurocholate>sodium cholate systems in all cases. In the sodium cholate and sodium taurocholate systems, the curves relating the electroconductive membrane permeability with concentration showed distinct changes in gradient at around the concentration of primary micelle formation of each bile acid solution. This was attributable to an increase in membrane/solution distribution of bile acid anion on basis of the micelle formation. Using diffusional dialysis, 7.3% of sodium ion was removed from rat serum. Sodium ion was significantly reduced with increasing total bile acid concentration in rat serum (P<0.05; correlation coefficient=−0.606).

Radioactive Iodine Waste Treatment using Electrodialysis with an Anion Exchange Paper Membrane

Abstract In order to simply and safely treat radioactive iodine waste, a study of the removal of the iodide ion from radioactive waste using electrodialysis with an anion exchange paper membrane, in which trimethylhydroxylpropylammonium groups were homogeneously dispersed at a high density. In a Na125I and Na36Cl concentration-cell system, phenomenological coefficients including electric ion and water conductance, have been experimentally determined on basis of nonequilibrium thermodynamics. Prepared paper membranes had a higher permselectivity for 125I ions than 36Cl ions by approximately 21%. On the other hand, water flux, accompanied by an ionic transference in prepared paper membranes was greatly larger than that in typical synthesized membranes. This observation suggested that a depression of water mobility is important to practice an ideal radioactive iodide waste electrodialysis system with a novel anion exchange paper membrane.