Image:Hernandez-Soriano Abstract Extended 2008.pdf

Heavy metals contamination of soil is mainly due to industrial, urban, and farming activities. These pollutants are persistent in soil and pose a potential risk for human health and ecosystem functioning. Surfactants are introduced in the environment by wastewater discharge, point-charge pollution or deliberate action, and may solubilize metals through complexation. Batch assays were performed to evaluate the effect of surfactants on metal concentrations in soil solution. Anionic surfactants (Aerosol 22, Biopower and SDS) were added to two soils. Four consecutive extractions were carried out, to evaluate the effect of continuous application of those compounds. The concentration of heavy metals in the equilibrium solution was determined, as well as dissolved organic carbon (DOC) and UV absorbance. All the anionic surfactants increased the concentration of Cd, Cu, Zn and Pb in soil solution. Addition of Aerosol 22 (10 mM) increased concentrations of Cd, Cu and Zn in solution up to 10 times, presumably through complexation of metals with the dicarboxy-ethylgroup of the surfactant.