Transfer and Partitioning of Heavy Metals Leached from Mswi Bottom Ash in a Column of Road Soil

In the field of road construction with alternative materials – among which Municipal Solid Waste Incinerator (MSWI) bottom ash the preservation of groundwater and soil quality is a major environmental issue as, under the effect of rainfall infiltration through road structure, heavy metals can leach out of the material and infiltrate into the underlying road soil. The later can act as a pollution filter and protect groundwater from contamination. Therefore, a better knowledge of the interaction between leached heavy metals and the road soil quality, from the short to the long term is needed. This study evaluated the mass transfer and the partitioning of Pb and Zn leached from a MSWI bottom ash sample and infiltrated into a column of silty soil (50 cm thick, 24 cm in diameter). The soil was compacted according to the normal Proctor reference. The percolating solution into the column was sampled at various depths for pH and concentration measurement. Vertical profiles of heavy metal content in the polluted road soil were carried out. To better understand the phenomena of sorption, the sequential extractions were carried out at different depths of the road soil.