137Cs Adsorption and Desorption on Marine Sediments from the Upper Gulf of Thailand

Sediments play an important role on fate in the diffusion of radionuclide in aquatic systems. In this study, the investigation of the adsorption/desorption kinetic of 137Cs in two different characteristic of marine sediment samples (organic matter, CEC, and clay content). Batch experiment was carried out from the Upper of Gulf Thailand. The results have shown that there is a significant percentage of 137Cs is adsorbed in both marine sediments during the first 48 hour that increased adsorption percentage to 82 and 86% and after that become to stable. On the other hand, the desorption of 137Cs was found both marine sediment were desorbed less than 10 % and become to stable desorption after 24 hours. Among different marine sediments (St.1 and St.21), the Kd value (distribution coefficients) of 137Cs was different which Kd of sediment from station 1 more than station 21(342.9 and 247.5 L/kg respectively). Differences in the characteristics of marine sediments affect to different the Kd value.