Evaluation of geomembrane, amended soil and composite liner system as lining materials for chromium decontamination in landfill site

Abstract

A comprehensive laboratory and field-scale study was performed to explore the efficacies of geomembrane, amended soil liner material and composite liner packs for using as containment liner systems for attenuating chromium transport emanating from a chrome laden solid waste disposal site. Soil samples were collected from the site and were admixed with different amended materials, such as rice husk and bentonite. Permeability tests were conducted in each of the cases by which the optimum values of different proportions of amended materials were determined to get maximum reduction in hydraulic conductivities. Field test results also showed that about 80% and 86% concentration of hexavalent chromium was sorbed after 120 days interval for geomembrane and amended soil liner, respectively. Comparative evaluation on performance of all these liner materials exhibit excellent ability to contain hexavalent chromium and amended soil material as an economically viable option among those for selecting as appropriate lining materials.