Characterization of Sn-Apatites and 99mTcO4 – anions removal from aqueous solutions

Abstract

Abstract Apatite is a natural mineral from the group of phosphate minerals. It originates primarily in rocks and converted limestones. It is also one of the few minerals produced and used by microeconomic systems. Due to its low solubility in water and high sorption capacity, apatite is a suitable sorbent for heavy metals and radionuclides removal from aqueous radioactive waste. Increasing amount of radioactive waste (RAW) has a negative impact on human health as well as on the environment. Production of RAW is constantly increasing because of the use of nuclear energy as well as by the development of nuclear medicine. The aim of this work was to study the effect of pH and various anions on the sorption of pertechnetate anions from aqueous solution to Sn-Apatite. Sn-Apatite samples used in the experiment were prepared by the wet precipitation method and adsorption of 99mTc was monitored by the radioisotope indication method. Sorption experiments were performed using the batch method. It was found that the sorption percentage was higher than 90 % in all Sn-Apatite samples and the dissociation constant, KD, indicated high affinity of pertechnetate anions to the solid Sn-Apatite particles. The presence of competing anions did not significantly influence the ability of Sn-Apatite materials to adsorb 99mTcO4 - from aqueous solutions.