Laboratory Model Test for Heavy Metal-Contaminated Soil Remediation Using PVDs

Abstract

Laboratory remediation experiments were carried out through the use of Prefabricated Vertical Drains (PVDs) to remediate soil contaminated with heavy metals. In the ground with lower permeability, the extraction of contaminants and the transmission of fluids are difficult; thus, to improve the injection or extraction of surfactants and to overcome difficulties due to micro pores in the soil, PVDs were used. For band-type drains, experiments comparing the effectiveness of filters coated with reactive material with the effectiveness of uncoated filters were conducted, and for cylindrical-type drains, experiments comparing the effects of the injection of surfactants were carried out. The heavy metal contaminants used in the experiments were Cu, Pb, and Cd, and concentrations over time were measured to assess the remedial efficiency. In the experiments, the initial concentrations were determined in consideration of the Korean Soil Contamination Warning Standards. The results from the experiments showed that the removal rates for Cd and Cu were 40% while that for Pb was 35% in the case of extraction alone. In the case of extraction with the application of reactants, the removal rates for Cu and Cd were 60% while that for Pb was 55%. In the case using both the reactant coating and cleansing agent injection, the removal rates were 74%, 65%, and 58% for Cd, Cu, and Pb, respectively.