Source Area of BioREmediation
Chlorinated solvents and other dense nonaqueous phase liquids (DNAPLs) are widespread groundwater contaminants. Bioremediation within DNAPL source zones is a promising approach for degrading these contaminants to harmless products because some dechlorination microorganisms can survive in otherwise toxic DNAPL source zones and by their activity facilitate the dissolution of DNAPLs. Modelling of immiscible phase tetrachloroethylene (PCE) and trichloroethylene (TCE) biodegradation does not yet properly account for the complexity of processes observed in Laboratory studies. The goal of SABRE is to determine if enhanced anaerobic bioremediation can result in effective and quantifiable treatment of chlorinated solvent DNAPL source areas. SABRE is a public/private consortium of twelve companies, two government agencies, and three research institutions across US, Canada, and UK. The focus of this 4-year $5.7 million research and development project is a field site in the United Kingdom containing a DNAPL source area with groundwater concentrations approaching TCE solubility. The project, involving complimentary Laboratory and numerical modelling research, began in October 2004.
ECOL collaborated with the University of Edinburgh on a comprehensive numerical model for simulating the dehalogenation of chlorinated ethenes. The model considered the kinetic dissolution of DNAPL, bacterial growth and decay, and the interaction of biological and geochemical reactions that might influence biological activity, particularly in the proximity of high DNAPL saturations. In addition to the standard biodegradation pathways, fermentation, methanogenesis, and iron and sulphate reduction processes was incorporated. Field-scale modelling were carried out. This process-based modelling supported laboratory and field work for the first in situ field DNAPL source area bioremediation trial in Europe.
Contact: Professor D. Andrew Barry