Role of final cover soil in regulating volatile organic compounds: emissions from solid waste disposal sites in developing countries

The objective of this study was to investigate the emission of Volatile Organic Compounds (VOCs) from solid waste disposal sites and their remediation at final cover soil. This research was conducted using field cover soil lysimeters placed at the surface of a solid waste dumping area and batch experiments in the laboratory. It was found that benzene, toluene, chloroform and perchloroethylene (PCE) were the major VOCs found in municipal solid wastes. Chloroform was found at highest concentration of 4240 +/- 1215 nmol/m(3) followed by benzene (831 +/- 439 nmol/m(3)), PCE (478 +/- 200 nmol/m(3)) and toluene (145 +/- 93 nmol/m(3)). Batch experiments revealed that an increase in soil moisture content from 0% to 5% for clay and 0% to 10% for sandy loam reduced the adsorption of VOC on soil particles. Therefore, it is most important factor in controlling VOC emission from solid waste disposal site. The adsorption was increased with increasing VOC concentration in gaseous phase. By placing sandy loam and clay final cover soil layer, VOC emission from solid waste disposal site could be reduced by 60-99%.