Biosurfactant concentrations will also be measured periodically in the outflow samples with a surface tensiometer. A bromide tracer pulse will be used to quantify the hydraulic parameters of each column. A series of supporting batch experiments will also be performed to determine equilibrium sorption isotherms for both atrazine and phenanthrene on the soil and sorbents selected. Similar equilibrium sorption experiments with biosurfactant added will be required to assess the changing solubility of the contaminants with changing surfactant concentration. These sorption experiments will also be used to determine the appropriate biosurfactant input concentrations for the column experiments.
Experimental work is ongoing.
I expect to defend my dissertation in the spring of 2001. Bioavailability and Desorption Characteristics of Aged, Nonextractable Atrazine in Soil. Environmental Toxicology and Chemistry.