Contaminated site remedial investigation and feasibility removal of chlorinated volatile organic compounds from groundwater by activated carbon fiberadsorption

Groundwater contaminated by dense, non-aqueous phase liquids (DNAPLs) such as chlorinated solvents has become a serious problem in some regions of Tai wan. The sources of these contaminants are due to industrial discharges. Th ese chlorinated volatile organic compounds (VOCs) have been proven to be ca rcinogenic to humans. The groundwater is used for domestic drinking water s upply in some cities of Taiwan and the severely contaminated groundwater ha s to be treated in order to meet the requirement of drinking water standard s. This study covers two areas of work. In the first part, polluted groundw ater samples were collected from the contaminated site and analytical resul ts indicated measurable concentrations of 12 representative chlorinated VOC s in water samples. The primary VOCs detected included trichloroethene (TCE ), tetrachloroethene (PCE), 1,1,2-trichloroethane (1,1,2-TCA), and I,l-dich loroethene (1,1-DCE). Second, to remove VOCs groundwater was treated using adsorption on activated carbon fiber (ACF). This involved pumping groundwat er through vessels containing ACF. Most VOCs, including TCE, PCE, I,1,2-TCA , and DCE, were readily adsorbed onto ACF and are removed from the water st ream. Our study showed that the technology was able to significantly reduce chlorinated VOCs concentrations in groundwater. (C) 2000 Elsevier Science Ltd. All rights reserved.