The comprehension of the behavior of radioactive nuclides in aquifer requires the study of the sorption processes of nuclides
in various geochemical conditions. The sorption/desorption of 65Zn(II) on surface sediments (0-2 cm) was investigated by batch method in sea water (pH 8.20, 35‰ salinity, filtered by 0.45mm)
at ambient temperature. The surface sediments were obtained from four stations around the Daya Bay of Guangdong Province (China),
where the first nuclear power station of China has been running from 1994. The sorption process is fast initially and around
39% average of sorption percentage (SP%) can be quickly obtained in 15 minutes for all the surface sediments. Then, the sorption
percentage becomes constant. In 30 days of contact time 79.6% sorption percentage and Kd=3.9. 103ml/g distribution coefficient was obtained. The value of Kdbecame constant, 4.0. 103ml/g, in contact time more than 120 hours. The distribution coefficient Kddecreases with increasing sediment concentration from 4.0 to 250 mg/l from 1.31. 104to 1.68. 103ml/g, respectively. Then the value of Kdgoes up to 5.38. 103ml/g with sediment concentration of 3000 mg/l. The desorption experiments suggest that the sorption of Zn(II) is irreversible
with a hyteresis coefficient of 66%.