2-Phase Extraction and Gas-Phase Bioreactor Treatment of TCE in Soil and Groundwater Volume I: Text

摘要

This report (volume 1 of 2) documents a test of the high vacuum 2- PHASE Extraction (2-Phase) process for the removal of trichloroethene (TCE) in soil and groundwater that was conducted at F.E. Warren Air Force Base (AFB), Wyoming. TCE offgased from the 2-Phase system was treated using a vapor phase bioreactor. Dual phase and pump and treat extraction were also tested for comparison to the 2-Phase system to determine which system would be most suitable for use at F.E. Warren AFB. The integration of the 2-Phase system with the vapor-phase bioreactor was successful. Greater than 95% of dissolved TCE in groundwater was stripped into the vapor-phase by the 2-Phase process. Activated carbon was used to remove the small residual. Ground water concentrations ranged from 100-1000 mg/L during the test. The gas-phase reactor demonstrated 85% to 90% TCE removal efficiencies at inlet TCE concentrations ranging from 10- 700 mg/L (17.7 psia and 150 deg F). Because the comparison objective was added to the scope after the Treatability Study Test Design was complete, it was not possible to make definitive comparisons between the three system types due to the evolution of the scope of the project. However, based on this test, process knowledge and experiences at other sites the following conclusions were drawn: 2-Phase is likely to be more cost effective in tighter formations, and pump and treat or traditional (low vacuum) dual phase is likely to be more cost effective in more productive formations.