Cyclodextrin Enhanced In-situ Removal of Organic Contaminants from Groundwater at Department of Defense Sites
RHODE ISLAND UNIV KINGSTON
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Funded by the Environmental Security Technology Certification Program ESTCP, this technology demonstration was intended to show the potential of cyclodextrin enhanced flushing technology CDEF under full-scale operational conditions. The particular objectives of this demonstration were 1 evaluation of the cost and performance of cyclodextrin CD enhanced removal of dense nonaqueous phase liquids DNAPL from polluted groundwater, 2 testing unrefined, liquid CD as substitute for CD powder, 3 evaluate membrane technology for recovering and reusing CD, 4 identifying most appropriate wastewater treatment technology-ies, and 5 conducting partition tracer tests PTT for mass balancing. This project was intended as a technology demonstration only the remediation of the entire test site was not an objective. The overall duration of the demonstration was 4 months, during which approximately 32.5 kg TCE and 1,1,1-TCA plus an estimated 3 kg of 1,1-DCE and an unknown amount of other contaminants were removed total DNAPL volume removed ca. 30 liters. The resulting decrease in DNAPL saturation was approximately 70 to 81. The principal performance measure for DNAPL removal were partition tracer tests conducted before and after the CDEF tests and mass balance calculations based on the amounts of recovered VOC contaminants. TCE concentrations in the reference wells declined between 38.5 to 99.4 average 77.3 from their pre-CDEF levels. Liquid, technical grade CD has been demonstrated to perform equally well than the more expensive powder CD tested during previous field applications. Further, CD solution recovered from the subsurface was reused after treatment without indications of decreased removal effectiveness. An ultrafiltration UF system was capable reconcentrating recovered CD solution from 5 to 20 wtwt, but the treatment capacity of the UF used during this demonstration was low and prevented continuous in-line operation.
- Organic Chemistry
- Physical Chemistry
- Hydrology, Limnology and Potamology
- Water Pollution and Control