Монтморилоніт Огланлинського родовища та магнітні композити на його основі – сорбенти для очищення вод від 137Cs та 90Sr

Abstract

A comparative study on the extraction of 137Cs and 90Sr from aqueous media using magnetic composites obtained on the basis of bentonite from the Ohlanlynske deposit and magnetite was carried out. It is shown that magnetic composites based on a natural mineral — bentonite rock, isolated montmorillonite in the Na-form, impurities — clinoptilolite and cristobalite, as well as natural minerals without magnetite, efficiently sorb 137Cs and 90Sr in a wide pH range (3.7–9). Despite the fact that magnetite in the composition of composites practically does not affect the efficiency of purification of aqueous media, but acts as only a magnetoactive component, composites are quite promising sorbents for purifying of large volumes of radioactively contaminated waters due to the possibility of removing water purification sludge using an external magnetic field. It has been established that the highest sorption properties are possessed by magnetic sorbents obtained on the basis of clinoptilolite — for 137Cs, and the Na-form of montmorillonite — for 90Sr. The values of their limiting adsorption by the indicated composites, calculated using the Langmuir equation, are 43.3 and 40.6 mg/g, respectively. It is shown that among the macrocomponents (Na+ , K+ , Ca2+), Ca2+ ions have the greatest influence on the efficiency of purification of natural waters and liquid radioactive waste containing 137Cs and 90Sr radionuclides.