| In the present study, a novel, ex situ, single culture treatment strategy using the bacterium, Sphingomonas aromaticivorans B0695, was examined. This strategy employs a two-liquid phase partitioning bioreactor (TLPPB) characterized by an organic phase into which PAHs are loaded at high concentrations, and then allowed to partition into a cell-containing aqueous phase to maintain maximum aqueous concentration as the PAHs are biodegraded by the bacteria. Selection of the organic solvent was based on a number of criteria: lack of bioavailability to the bacterium; low cost; low volatility; a log P value of 4.0 or greater; and low solubility in the aqueous phase. A concurrent investigation, in collaboration with a Canadian company, was performed on solvent extraction techniques for removing PAHs from soil. This prior step is intended to remove soil contaminants and the solvent (loaded with PAHs) could be used directly as the organic phase in a TLPPB. Based on the criteria listed above and the requirement for use in solvent extraction, dodecane was chosen as the organic solvent. (Abstract shortened by UMI.). |
