The applicability of zirconium phosphate-ammonium molybdophosphate (ZrP-AMP) for the efficient removal of cesium from aqueous acidic solutions by adsorption has been investigated. The adsorption data analysis was carried out using the Freundlich, Dubinin-Raduskevich (D-R) and Langmuir isotherms for the uptake of Cs in the initial concentration range of 3.75 . 10 -5 -7.52 . 10 -3 mol . dm -3 on the ZrP-AMP exchanger from nitric acid medium. The mean free energy ( E ) values for the adsorption of Cs were obtained from the D-R isotherm. Equilibrium adsorption values at different temperatures have been utilized to evaluate the change in enthalpy, entropy and free energy (Δ H °, Δ S °, Δ G °). The adsorption of cesium on the ZrP-AMP exchanger was found to be endothermic.

A new inorganic ion exchanger, zirconium phosphate-ammonium molybdophosphate (ZrP-AMP) has been prepared in granular form, suitable for column operation. The results obtained from TG-DTA, IR and X-ray diffraction studies for this exchanger are presented. The k(d) values for different metal ions were determined and the affinity order was found to be Cs>>Rb>Zr>Ce>rare earths. pH titration curve, breakthrough capacities for cesium in different types of simulated nuclear wastes and elution of cesium from ZrP-AMP column have been studied. Conditions for separation and isolation of cesium from other fission products in simulated waste solutions have been established. The exchanger was found to be stable to ay-radiation dose of 10(8) rads.

tium on vermiculite and ZrMV increased with increase in pH and lowering concentration of Sr 2+ . The rate of uptake of strontium by ZrMV was found to be much faster than that for vermiculite. The distribution coefficient of strontium on ZrMV is of the order of 10 4 mL/g at pH 3, and the amount of strontium sorbed on ZrMV was always found to be much higher than that on the parent clay. The sorption data were fitted to Langmuir adsorption model for obtaining the sorption capacity of the sorbent. Increase of temperature increases the distribution coefficient of strontium on both ZrMV and vermiculite. Distribution of strontium on ZrMV was also determined from the groundwater samples obtained from the waste disposal site at Kalpakkam.

A composite mixture of zirconium molybdate and zirconium tungstate was prepared and studied for the sorption of cesium and strontium as a function of nitric acid, metal ion concentration, time and temperature. The distribution coefficient (K d ) of 7000 ml/g (~90% sorption) and 70 ml/g (~20% sorption) was obtained for the sorption of cesium and strontium in 0.1M nitric acid, respectively. Experimental sorption capacity, b for cesium was found to be 50 mg/g from 0.1M HNO 3 and 30 mg/g for strontium from 0.001M nitric acid. The sorption of strontium on the sorbent was accompanied by the absorption of heat but the sorption of Cs + results in the liberation of heat. Column studies were conducted by following a breakthrough (BT) curve of cesium and strontium up to C/C 0 =1 and the results are reported.