Digital Commons Network^™

Biosorption And Transformation Of Tetra-Chloroethylene And Trichloroethylene Using Mixed-Species Microbial Mats, W. L. O'Niell, V. A. Nzengung, J. E. Noakes, J. Bender, P. C. Phillips

Journal of Hazardous Substance Research

Microbial mats are naturally occurring assemblages of aquatic organisms capable of sorbing and degrading various organic compounds. Kinetic transformation and sorption experiments were conducted in sealed batch vials, using microbial mats dosed with unlabeled tetrachloroethylene (PCE) and trichloroethylene (TCE) and radiolabeled forms of these compounds ([₁₄C]PCE and [₁₄C]TCE). Results indicated that sorption equilibrium was attained for both chemicals within a few hours. The sorption isotherm was linear, demonstrating that the sorption mechanism was partitioning. PCE was completely degraded in periods as short as 50 days under favorable growth conditions. Samples were also tested for degradation products, …

Effect Of Vegetation On Transport Of Groundwater And Non-Aqueous Phase Liquid Contaminants, Q. Zhang, L. C. Davis, L. E. Erickson

Journal of Hazardous Substance Research

An aquifer model system was established to examine and delineate the presence, fate and transport of nonaqueous-phase liquid (NAPL) contaminants. The system consists of six independent channels with identical dimensions. The channels were constructed with steel bottoms, side panels, and end panels. Trichloroethylene (TCE) was selected as a representative compound to model NAPL groundwater contaminants in the saturated zone of the aquifer.

The flow regime of groundwater in the saturated zone was investigated by conducting a bromide tracer experiment. The movement of TCE in both horizontal and vertical directions was studied by monitoring the ground- water effluent stream and the …