Bioavailability and Redistribution of Trace Metals in Soil Washed with a Sulfosuccinamate Formulation

Leaching tests using single and sequential extraction procedures were conducted in four contaminated soils to evaluate changes in metal partitioning before and after washing with the anionic sulfosuccinamate surfactant Aerosol 22 (A22). Evaluation of metal redistribution is of major importance to understand trace metals behaviour and reduce environmental risks. For the four soils, differing in the level of contamination, the distribution of metals in the four fractions was altered after washing with A22, which may be due to the strong extraction and complexation potential of the carboxylate function in the sulfosuccinamate surfactant. Besides, results from sequential extraction showed that, in general, surfactant largely extracted the metals bound to the carbonates and organic matter, while only a minority percentage of extraction corresponded with the oxyhydroxides fraction. Single extractions confirmed that the presence of the sulfosuccinamate compound in soil increases metal bioavailavility and therefore comprises a risk for the environment.