Heavy lead (Pb) mobility in compacted clay soils under landfill liners

Abstract The movement of heavy metals and their concentration depth is an important aspect of landfill design. This paper presents the results of laboratory measurements of lead (Pb) mobility in compacted clay soils of landfill liners. The contaminant transport of the heavy lead metal through a compacted landfill barrier was modeled utilizing a 50 cm column leaching test. Test results gave clear indication that the highest surface concentration lead was measured in the top 20 cm layer suggesting that the clay liners should be constructed with at least 20-30 cm thickness with 98% compaction level. It is clear that as long as the porosity are maintained very low by the use of modified proctor procedure it is possible to maintain the heavy lead on the top 20 cm depth once the geomembrane layer fails. This study suggests that experimental sample height should be higher than 20 cm in contrast to conventional 10 cm thick samples.