Arun R. Gavaskar

Design and construction techniques for permeable reactive barriers.

Adequate site characterization, bench-scale column testing, and hydrogeologic modeling formed the basis for the design and construction of permeable reactive barriers for groundwater remediation at various sites, such as Dover Air Force Base, DE and Naval Air Station, Moffett Field, CA. Dissolved chlorinated solvents, such as perchloroethylene (PCE) and trichloroethylene (TCE), have been the focus at many sites because the passive nature of the reactive barrier operation makes such barriers particularly useful for treating groundwater contaminants that can persist in the aquifer for several years. A combination of conventional and innovative site characterization, design, and construction techniques were used at these sites to increase the potential cost effectiveness of field application.

Treating contaminated sediment with a two-stage base-catalyzed decomposition (BCD) process : bench-scale evaluation

Abstract The New York/New Jersey (NY/NJ) Harbor estuary sediment contains polychlorinated dibenzo-p-dioxins/furans ( PCDDs PCDFs ), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and chlorinated pesticides. The U.S. EPA-developed two-stage base-catalyzed decomposition (BCD) process was tested for removal and decomposition of these organic contaminants of concern (OCCs) from the sediment. The Stage 1 process removed OCCs to below the limits of analytical quantitation (LAQs) or the limits of the potentially applicable requirements (LPARs), and concentrated OCCs into a small volume of organic condensate for Stage 2 chemical destruction. The aqueous condensate fractions contained some nondestroyed contaminants, either at levels below LPARs or at levels that could be treated by conventional treatment processes. Factors such as chemical addition, water content, and residence time were examined for their effects on the treatment process. Mass balances were calculated. The distribution of metal contaminants was determined.

EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT

This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtration and distillation, Results show that the filtration unit evaluated needs improvement to ensure an acceptable quality of the recycled coolant. Distillation results show that this technology provides acceptable product quality and good waste reduction and economic potential. The New Jersey garage could potentially reduce waste from over 8000 gals/yr to approximately 400 gal/yr. The recycled product in the distillation evaluation passed selected ASTM performance tests. Boiling point, freezing point, pH, corrosion resistance, and foam control functions of the coolant were restored to specifications. Chemical characterization of the recycled coolant showed that metals, salts and organic contaminants were either removed or reduced to...