Combining Low-Energy Electrical Resistance Heating with Biotic and Abiotic Reactions for Treatment of Chlorinated Solvent DNAPL Source Area
Abstract
The effectiveness and timeframe of in situ remedies such as in situ bioremediation (ISB) and zero-valent iron (ZVI) is a function of mass transfer when applied in chlorinated solvent dense nonaqueous phase liquid (DNAPL) source zones. The ESTCP ER-0719 project demonstrated combining low-temperature subsurface heating with in situ remedies to enhance remediation performance through both increased degradation reaction rates and contaminant dissolution. Dechlorination was induced in two test cells for ZVI and ISB. For the ZVI test, increased temperature from 10oC to between 35 and 45oC increased dechlorination by a factor of 4 to 8. For the ISB test, increasing the temperatures (10oC to between 35 and 45oC) accelerated overall contaminant dechlorination by a factor of 2-4 at hotspot locations close to residual contaminant mass. Field test results demonstrated that moderate heating and minor operational costs enhanced efficiency and effectiveness of in situ treatment of trichloroethene (TCE). Capture and treatment of contaminated vapor a major cost element of standard thermal treatment was not needed as treatment maintained low aqueous TCE concentrations. Additional infrastructure needed for heating was limited to subsurface electrodes and a power control unit. These results suggest that combined heating and in situ treatment may be cost effective in source zones with moderate contaminant mass or when combined with hightemperature thermal.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2012
- Accession Number
- ADA594451
Entities
People
- Mandy Michalsen
- Michael Truex
- Tamzen Macbeth
- Thomas Powell
Organizations
- Applied Research Associates (United States)