The effect of redox potential on the electrokinetic remediation of mercury contaminated soils
- Univ. of Tennessee, Knoxville, TN (United States)
An electrokinetic process for remediation of mercury contaminated soils using an iodine-iodide lixiviant was developed. In this process, reduced forms of insoluble mercury are oxidized by iodine. Iodide then reacts with mercury to form the highly soluble HgI{sub 4}{sup 2-} complex, which in turn migrates toward the anode via electromigration. The objective was to determine the thermodynamic conditions under which mercury could be solubilized and transported from the soil. At the end of the electrokinetic treatment process, pH, pE, iodine, iodide, and soluble and total mercury were measured along the length of the soil. The process was tested on a soil contaminated with HgS (cinnabar) in the laboratory and a contaminated soil obtained from a hazardous waste site. Up to 99% overall removal of mercury could be achieved from the laboratory contaminated soil. Up to 84% of mercury was removed from some sections of the field contaminated soil, but overall removal was only 6%. The presence of iodine in the soil pore water was found to be the most important factor in solubilization of mercury. Residual levels of soluble Hg remaining in soil after treatment were greater than allowed by current regulations and far in excess of the solubility of Hg compounds present in the untreated soil.
- OSTI ID:
- 416880
- Report Number(s):
- CONF-951023-; TRN: 96:005001-0037
- Resource Relation:
- Conference: 68. annual conference and exposition of the Water Environment Federation, Miami Beach, FL (United States), 21-25 Oct 1995; Other Information: PBD: 1996; Related Information: Is Part Of WEFTEC `95: 68th annual conference & exposition; PB: 498 p.
- Country of Publication:
- United States
- Language:
- English
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