Solvent Extraction and Tandem Dechlorination for Decontamination of Soil
The United States Environmental Protection Agency (US EPA) guidelines allow removal of polychlorinated biphenyls (PCBs) from soils via solvent extraction. This option holds promise for removal of other recalcitrant organic contaminants as well. A study was undertaken to evaluate the effectiveness of solvent extraction with two tandem degradation techniques. The degradation techniques were chemical dehalogenation with immobilized reagents and γ-ray irradiation. The integrated approach was evaluated with contaminated soils from wood treatment and electric power substation sites. Evaluations were carried out on a bench scale in the laboratory and on a semi-pilot scale at a contaminated site. Binary solvent mixture of alkanes and alcohols yielded the highest extraction efficiencies. Extraction efficiencies in excess of 90% were obtained for PCBs, polychlorinated dibenzo-p-dioxins (PCDDs) and polynuclear aromatic hydrocarbons (PAHs). Extracted PCBs were rapidly degraded through chemical dehalogenation or with high doses of the γ-ray irradiation. The residual organics in the solvent mixture were removed with activated carbon, and the solvent was recycled for subsequent soil extractions. Contaminants adsorbed on the activated carbon were destroyed with a counter flow oxidation process.
P. K. Nam et al., "Solvent Extraction and Tandem Dechlorination for Decontamination of Soil," Chemosphere, Elsevier, May 2001.
The definitive version is available at http://dx.doi.org/10.1016/S0045-6535(00)00398-2
Chemical and Biochemical Engineering
Mechanical and Aerospace Engineering
United States. Department of Energy
Library of Congress Subject Headings
Article - Journal
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