Improving Effectiveness of Bioremediation at DNAPL Source Zone Sites by Applying Partitioning Electron Donors (PEDs).

摘要

Enhanced In situ bioremediation (EISB) can be a low-cost approach for accelerating remediation timelines at sites impacted with dense non-aqueous phase liquids (DNAPLs) such as trichloroethene (TCE) and tetrachloroethene (PCE). EISB typically relies on the addition of electron donor formulations to enhance the rate of dissolution and reductive dechlorination. Although vegetable oil is a low cost electron donor, it is typically added in excess amounts to ensure that it is distributed effectively. It has been demonstrated by Harkness (2000) that the cost of electron donor can represent up to 50% of the net present value (NPV) cost when applied using passive (i.e., biostimulation) methods. Hence, the selection of electron donors has a major implication on EISB cost. The objectives of the field demonstration/validation (DEM/VAL) included: 1.) Demonstrate application of the PED technology at field scale, assess the ability to distribute PED within the source area and enhance biodegradation; 2.) Validate the enhanced performance and efficiency of DNAPL dissolution and dechlorination following the injection of a PED. 3.) Collect cost and performance data for the application of PEDs for source zone bioremediation and provide reliable technical data relevant to field-scale implementation of the PED technology, including documentation of the expected reduction in duration and cost of remediation of DNAPL source sites.