Abstract
Batch sorption test and selective sequential extraction were conducted for two types of bentonite mixture using basalt soil and Andosol to examine the effect of salinity for their lead sorption abilities. Increase in salt concentration of solution decreased the lead sorption of the soil mixtures. Particularly exchangeable phase of lead sorbed in basalt soil mixture decreased with the increase in the salt concentration. Due to the high buffer capacity of allophane contained in Andosol, Andosol mixture exhibited the higher lead sorption ability than basalt soil mixture. Buffer Prediction of lead leaching by convection-diffusion equation showed that the high salt concentration increased the mobility of lead in the clay liner. The leaching speed of basalt soil mixture was the three times higher than that of Andosol mixture. These results suggest that Andosol is effective material for reduction of lead mobility in clay liner.
