Preparation of Inorganic Strontium Adsorbent and Its Application

In order to remove ⁹⁰Sr from the liquid radioactive waste, a novel of inorganic adsorbent MnO₂ was prepared through the reaction of potassium permanganate with manganese chloride in the pH=10-12 aqueous solution, under the 60℃ water bath condition. The material sample was characterized and analyzed by X-ray diffraction method. The adsorbent was studied through the static experimental test in details, and compared with several common natural strontium sorption materials. The results indicate that the adsorption effect of the adsorbent for ⁹⁰Sr is obviously better than those of other sorption materials. The adsorption rate of the adsorbent for ⁹⁰Sr is very fast, and the adsorption can reach equilibrium in about 20 min. The adsorbent has high theoretical saturated adsorption capacity (Q=0.52 mmol/g) and distribution coefficient (K_d). The typical K_d value is about 10⁴ mL/g. The influence of HNO₃, Na⁺, K⁺, Co²⁺ and Ca²⁺ concentration on the adsorption for ⁹⁰Sr were studied in this paper. The results show that the K_d value decreases rapidly with increasing the concentration of HNO₃, when the concentration of nitric acid is 0.01 mol/L, and the K_d value is about 6×10³ mL/g. When the concentration of nitric acid is 0.1 mol/L, the K_d value is only 6 mL/g yet, that reduces 3 orders of magnitude. The content of monovalnet cations Na⁺, K⁺ have little effect on the K_d value. While the two divalent cations Co²⁺, Ca²⁺ have great influence on the K_d value, it rapidly decreases with the increase of ion concentration. At last, the adsorbent was used to remove the ⁹⁰Sr in the simulated and real radioactive waste liquid by dynamic experiments respectively. The results prove that the adsorbent has excellent adsorption performance for strontium, and it has good application prospect on the removal of ⁹⁰Sr from radioactive waste liquid.