Removal of U-234,U-238, Ra-226, Po-210 and Pb-210 from drinking water by ion exchange

Six organic and five inorganic ion exchangers were studied for the removal of natural radionuclides from drinking water. In the first phase, distribut ion coefficients (K-D) of uranium and radium were determined in three model solutions: a good quality water, an Fe-Mn-rich water and a saline water si mulant. The exchangers showing highest K-D's for U and Ra were tested in co lumn mode experiments for the removal of U, Ra-226, Po-210 and Pb-210 from a real ground water. Considering the total 1800 processed bed volumes, the best decontamination factors (DF) for U, 20-120, were obtained with the str ong base anion exchange resin. The most efficient exchangers for the remova l of Ra-226 were the weak and strong cation resins and zeolite A. With use of long regeneration intervals, conventional organic resins are thus most s uitable for the removal of radionuclides. When only a few hundred bed volum es were processed, with the corresponding regeneration interval about one w eek, the aminophosphonate resin was most effective for the removal of both uranium and radium. Po-210 and Pb-210 in ground water were mainly bound in particles and adsorbed on the surface of the anion resins. The use of the a minophosphonate resin to remove uranium and radium would therefore require an anion resin to take up polonium and lead.