NEW SELECTIVE ADSORBENTS FOR AMMONIUM-IONS - REGENERATION OF DIALYSATE IN PORTABLE ARTIFICIAL-KIDNEY

A method for a portable-type artificial kidney was recently proposed, based on enzymatic decomposition of urea to ammonia by urease, followe d by adsorption of ammonium cations on ion exchangers. To simplify the system we utilize new adsorbents selective for ammonium ions, e.g. cr yptomelane (crymo) crystalline form of manganese dioxide and/or copper -impregnated ion-exchange resins. The adsorption isotherms, ion exchan ge capacity and selectivity were measured for these adsorbents. The re sults of batch and column experiments with solution of ammonium ion wi th and without coexisting cations, demonstrate that the copper-impregn ated carboxyl resin with hydroxyl group attached, selectively removes ammonium cations and exhibits much higher capacity as compared with th e sorbents used in conventional system.