Solvent Extraction and Tandem Dechlorination for Decontamination of Soil

Abstract

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.

Department(s)

Chemistry

Second Department

Mechanical and Aerospace Engineering

Sponsor(s)

United States. Department of Energy

Keywords and Phrases

Carbon; Dechlorination; Decontamination; Gamma Rays; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Soils; Solvent Extraction; Counter Flow Oxidation Process; Atmospheric Chemistry; activated Carbon; Polychlorinated Biphenyl Derivative; Polychlorinated Dibenzodioxin; Polycyclic Aromatic Hydrocarbon; PCB; Pollutant Removal; Soil Remediation; Solvent; adsorption; Article; Dechlorination; Degradation; Extraction; Gamma Irradiation; Soil Pollution; Soil Treatment; arbon; Chemistry, Analytical; Chlorine Compounds; Environmental Pollutants; Halogens; Polychlorinated Biphenyls; Power Plants; Sensitivity And Specificity; Soil Pollutants; Tetrachlorodibenzodioxin; Irradiation

International Standard Serial Number (ISSN)

0045-6535

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2001 Elsevier, All rights reserved.

Publication Date

01 May 2001

Link to Full Text

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