Demonstration-scale analysis of anaerobic bioremediation of tetrachloroethene DNAPL source zone using bioaugmentation and electron donor delivery

An experiment was designed to test the hypothesis that bioremediation within DNAPL source zones is feasible provided all limiting factors are delivered in adequate amounts. A demonstration-scale aboveground aquifer simulation system was bioaugmented with a mixed anaerobic dechlorinating culture after the addition of neat PCE below the water table. Hydrogen Releasing Compound RTM was introduced to the tank to provide a long-term and steady supply of reducing equivalents for dechlorination. The system effluent was monitored for chlorinated ethene concentrations, and results demonstrated the dechlorination of PCE to trichloroethene (TCE) and cis-dichloroethene (cis-DCE). Measurements at the end of the study indicated the following mole fractions in the effluent: cis-DCE (66%), TCE (24%), and PCE (10%).