Influence of reducing conditions on metallic elements released from various contaminated soil samples.

The redox conditions of soil may have significant consequences for the mobility of metallic elements (ME), but unlike pH, very few studies have investigated this parameter. A procedure was established to study the solubilization of ME from soil samples in various reducing conditions using a batch method and sodium ascorbate solutions. The change in redox potential from +410 to +10 mV was studied from four contaminated soil samples (designated A-D) of different origins and compositions.

Sequential heavy metals extraction from polluted solids: influence of sulfate overconcentration.

The effect of sulfate on the chemical partitioning of Cu, Cd, and Pb in solid phases was assessed in this study. Modified BCR sequential extraction, speeded up by focused ultrasound, was systematically applied to various mixtures of typical geochemical solid phases (an artificial goethite spiked with Cu, Cd, and Pb and natural clays), with or without the addition of calcium sulfate. Sulfate was added so that three different concentrations were found in sequential extracts: 0.