Secondary impacts of in situ chlorinated solvent remediation due to metal sulfide precipitation and thermal treatment.

摘要

Chlorinated solvents are among the most widespread and persistent groundwater contaminants in the United States. While the primary effects of in situ chlorinated solvent remediation are relatively well understood, efforts to achieve site closure may be impeded because secondary impacts of remedial technologies have not been fully explored. Therefore, this research seeks to develop a fundamental understanding of the secondary impacts of two prominent in situ remediation technologies, bioremediation and thermal remediation, on groundwater quality. Groundwater flow studies were completed to assess the effects of iron (II) sulfide precipitation on the permeability of porous media. Batch experiments were completed to quantify electron donors released during thermal treatment, which may help sustain microbial reductive dechlorination. Experimental results show that precipitation can reduce the permeability of porous media and alter flow paths, and that thermal treatment of soils causes release of electron donors and electron donor precursors, primarily as volatile fatty acids.