Journal of Cleaner Production ( IF 5.651 ) Pub Date : 2019-02-06 , DOI: 10.1016/j.jclepro.2019.02.050 Shi Shu, Wei Zhu, Jiangwei Shi
Compacted clay liners and geomembranes are extensively used as bottom liners in municipal solid waste landfills, to minimize groundwater contamination due to the migration of landfill leachate. Seepage of leachate, however, can still transport pollutants in leachate through the bottom liner and cause environmental contamination. Design of a landfill site, therefore, requires estimation of the breakthrough time of the bottom liner. Current methods to calculate this breakthrough time are extremely complicated, so this study investigated a simplified calculation. For one–dimensional vertical transport of a key indicator pollutant, two simplified formulas are proposed to calculate breakthrough times of single compacted clay and composite liners. The proposed method considers pollutant transport mechanisms of advection, diffusion, mechanical dispersion, and adsorption. It is easy to use and can provide a reference for design, management, and subsequent restoration of such landfill sites.