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CONTROL OF VOLATILE ORGANIC CONTAMINANTS IN GROUNDWATER BY IN-WELL AERATION
Citation:
Miltner, R., J. Coyle, AND H. Borchers. CONTROL OF VOLATILE ORGANIC CONTAMINANTS IN GROUNDWATER BY IN-WELL AERATION. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-88/020 (NTIS PB88180112).
Description:
At a 0.1 mgd well contaminated with several volatile organic compounds (VOCs), principally trichloroethylene (TCE), several in-well aeration schemes were evaluated as control technologies. The well was logged by the USGS to define possible zones of VOC entry. A straddle packer and pump apparatus were utilized to isolate those zones and define their yield and level of VOC concentration. The technical literature together with this knowledge of the well were used to design an air lift pump. Operation of the air lift pump confirmed literature prediction of its low wire-to-water efficiency. Removal of TCE did not exceed 65 percent. Mass transfer occurred in the pump's eductor. Air lift pumping coupled with in-well diffused aeration increased TCE removal to 78 percent. When in-well diffused aeration was used with an electric submersible pump, TCE removal averaged 83 percent. In the latter two schemes, mass transfer occurred utilizing the well as a countercurrent stripper. These technologies are limited by the volume of air that can be transferred to the well (air-to-water ratios below 12:1) and the cost of compressing air under high head. Thus, these technologies are not cost-effective compared to packed tower aeration. They are, however, quickly put on-line, easy to operate, and can serve as good short-term remedies while above-ground technologies are under design and construction.