Abstract
The mechanism of electrolyte transport through a dialysis membrane should be clarified to improve inorganic phosphate removal from patients on long-term hemodialysis. Dialysis experiments were made with aqueous radioisotope (32P)-labeled disodium hydrogenphosphate mixed with sodium chloride or potassium chloride of varying ionic strengths. Inorganic phosphate ion permeabilities were obtained for regenerated cellulose (RC) and polymethylmethacrylate (PMMA) membranes. Aqueous sodium chloride or potassium chloride whose ionic strength equals that of an inner solution of the hollow fiber was used as dialysate. Permeability for inorganic phosphate ion of each membrane increased with the ionic strength of cations. On the same ionic strength, presence of cations of higher ionic mobility was advantageous to the permeability for inorganic phosphate. From the analysis based on the electrolyte diffusion theory, membrane structures would also affect on the membrane permeabilities. It is necessary to establish a new electrolyte diffusion theory, considering charge densities, membrane structures and membrane properties.
