EPA site demonstration of BioTrol aqueous treatment system.

BioTrol's pilot scale, fixed-film biological system was evaluated, under the EPA's SITE program, for its effectiveness at removing pentachlorophenol from groundwater. The demonstration was performed in the summer of 1989 at a wood preserving site in New Brighton, Minnesota. The system employs indigenous microorganisms amended with a specific pentachlorophenol-degrading bacterium. Groundwater from a well on the site was fed to the system at 1, 3, and 5 gpm with no pretreatment other than pH adjustment, nutrient addition, and temperature control. Each flowrate was maintained for about two weeks while samples were collected for extensive analyses. At 5 gpm, the system was capable of eliminating about 96 percent of the pentachlorophenol in the groundwater and producing effluent with pentachlorophenol concentrations of about 1 ppm. At the lower flows (1 and 3 gpm) removal was higher (about 99 percent) and effluent pentachlorophenol concentrations were well below 0.5 ppm. The system consistently produced a completely nontoxic effluent at all three flowrates. Review of other data provided by BioTrol indicates that the process is also effective on other hydrocarbons, including solvents and fuels. The system appears to be a compact and cost-effective treatment for contaminated wastewaters requiring minimal operating attention once acclimated.