2010 Volume 25 Pages 233-240
The capacity of geosynthetic clay liners (GCLs) to attenuate metals and metalloids such as Al, Fe, Cu, Zn, As, and Pb was evaluated in this study. For this purpose, free swell, sorption, and hydraulic conductivity tests on a needlepunched geosynthetic clay liner against a pH 3 artificial acid rock drainage (ARD) were conducted. Free swelling tests showed that at high metal concentration, the swell index decreased dramatically. Sorption test results showed that Na-bentonite had high capacity to sorb metals and metalloids. Hydraulic conductivity tests showed that k was 10 times lower when GCL was prehydrated with water, before permeating with ARD. Effluents were also evaluated in each case and results showed that the GCL tested has strong attenuation capacity toward metals and metalloids present in ARD, although desorption was observed in some cases.
