EVALUATION OF SYNTHETIC INORGANIC-ION EXCHANGERS FOR CESIUM AND STRONTIUM REMOVAL FROM CONTAMINATED GROUNDWATER AND WASTE-WATER

The ion exchange testing of 30 synthetic adsorbents including layered and framework polyvalent metal silicates and phosphates, as well as am orphous exchangers was carried out. Their selectivity to alkali and al kaline earth metal cations in individual and complex solutions was det ermined. Several exchangers were found to have high selectivity for ce sium and strontium. These exchangers are sodium phlogopite. layered so dium titanium silicate Na2TiSi2O7 . 2H(2)O, framework niobium (Na2Nb4S i2O15. 4H(2)O, tentative formula), zirconium (Na2ZrSi3O9 . H2O) and ti tanium (Na2Ti2SiO7 . 2H(2)O) silicates, and a layered delta-tin phosph ate (Sn(HPO4)(2) . 2H(2)O). For all these materials cesium and stronti um ion exchange capacities as a function of pH were determined. The ef fect of sodium, magnesium and calcium on Cs- and Si2- ions sorption wa s also studied over the concentration range 0.005 (M) under bar - 1.0 (M) under bar and the explanations for the phenomena observed were pro posed based on the knowledge of the crystal structure of the exchanger s. Testing of the most promising exchangers for selective cesium and s trontium recovery from ground water simulant in batch regime was carri ed out.