Effect of Environmental Conditions on Strontium Adsorption by Red Soil Colloids in Southern China

The fate of radionuclides in the environment is attracting increased attention. The effect of various environmental effects on the adsorption behavior of the strontium ion (Sr2+) by red soil colloids in Southern China was studied by a series of batch experiments, and the adsorption mechanism was briefly investigated as well. With the increase in the solid–liquid ratio and the concentration of Sr2+, the adsorption efficiency increased gradually. The effect of pH and ionic strength on adsorption was strong, while temperature had little effect. The adsorption data fitted to the Langmuir model indicates that the process is monolayered and homogeneous. The thermodynamic parameters also show that the adsorption of Sr2+ on red soil colloids is a spontaneous and exothermic process. The aim of this work is to gain insight into the role of red soil colloids on the fate of radionuclides in the field