Successful combination of remediation techniques at a former silver factory

Abstract

A residential area that was formerly part of a silver factory site severely contaminated with chlorinated solvents was remediated using an in situ electro-bioreclamation technique. Electro-bioreclamation is a method for heating soil and groundwater combined with soil vapor and low-yield groundwater extraction and enhanced reductive dechlorination (ERD). During the first two years of remediation in the source area (the intensive phase), a total of 80 kg of volatile organic compounds (VOCs) was removed by heating combined with ERD. After another two years of ERD in the source and plume areas (the attenuation phase), the VOC concentrations were reduced to a level below 100 µg/L in groundwater. Given these satisfying results, electro-reclamation in combination with ERD turned out to be a successful in situ remediation technique for removing VOCs.

Evaluation of EK System by DC and AC on Removal of Nitrate Complex

“…The electron donor provides a source of energy. An additional effect of increased temperatures is that organic compounds, such as humic and fulvic acids that are present in clay, dissolve in the soil and can also act as a carbon source (10). Hence, it is believed that the electron donor may supply electron to nitrate and reduces as nitrogen=ammonia gas.…”