Mineralogical and hydrochemical effects on adsorption removal of cesium-137 and strontium-90 by kaolinite.
Adsorption characteristics of the nuclides onto kaolinite were investigated by batch experiment under various pH conditions and concentrations of groundwater cations (Ca2+, Mg2+, K+ and Na+) and anions (HCO3-, CO3(2-) and SO4(2-). Adsorption removal of 137Cs and 90Sr by kaolinite greatly increased as the concentration of groundwater cations increased from 10(-5) to 10(-1) M. In contrast, the pH exerted a small effect on the adsorption of 137Cs and 90Sr onto kaolinite. The zeta potential of kaolinite particles showed a negative increase of amphoteric surface charge with increasing pH. The adsorption behavior of 90Sr was also highly dependent on the concentration of bicarbonate. The thermodynamic saturation index indicated that bicarbonate exerts great effect on strontium adsorption by the precipitation of a strontianite (SrCO3) and a change in pH.
Jeong
C H
CH
Department of Engineering Geology, University of Taejon, 96-3 Yongun-dong, Tong-gu, Taejon, 300-716, Korea. chjeong@dragon.taejon.ac.kr
D000327:Adsorption; D002588:Cesium Radioisotopes / Q000737:chemistry; D004787:Environmental Pollution / Q000517:prevention & control; D006863:Hydrogen-Ion Concentration; D007616:Kaolin / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013326:Strontium Radioisotopes / Q000737:chemistry; D014875:Water Pollutants, Radioactive / Q000032:analysis*
D002588:Cesium Radioisotopes; D012990:Soil Pollutants, Radioactive; D013326:Strontium Radioisotopes; D014875:Water Pollutants, Radioactive; D007616:Kaolin