Desorption response and degradation of buffering capability of bentonite, subjected to heavy metal contaminants

Changes in pore fluid chemistry due to leachate intrusion will change the physico-chemical properties and the attenuation performance of clay barrier materials. In the field, changes in the pore fluid chemistry will occur as a direct result of leachate intrusion from waste streams, discharges, leaking underground storage facilities, and waste disposal facilities – to name a few.This study investigates bentonite–contaminant interaction at different pH levels and heavy metals concentrations, with particular attention paid to the effect these have on the chemical behaviour of the bentonite soil. For chemical performance, the sorption characteristics of these specimens in relation to different pore fluid chemistries were studied. A series of batch equilibrium tests were performed at different concentrations of Zn2+ and Pb2+ and different pH levels to study the sorption properties of bentonite.