SORPTION MECHANISM OF RADIONUCLIDES ON CLAY MINERAL AND ZEOLITE FROM NaCl-NaAc AQUEOUS SOLUTIONS

This paper discusses the sorption characteristics of the radionuclides 137Cs,45Ca,65Zn,160Tb,169Yb from the NaCl-NaAc solutions (pH = 5. 0) on kaoline, bentonite, composite zeolite in the form of attrition-resistant microspheres and Y zeolite. The batch technique is used to determine the sorption ratios of these radionuclides on some silicate minerals. It is found that lgRD (sorption ratio)is linearly dependent on lgNa+ (concentration of sodium ion).From the sorption characteristics it is concluded that the ion exchange mechanism and surface com-plexation mechanism may occur at the silicate mineral/NaCl-NaAc aqueous solution interface.