ISOLATION AND USE OF INDIGENOUS BACTERIA FOR
BIOREMEDIATION OF SOIL FROM A FORMER WOOD
TREATMENT SITE IN SOUTHWESTERN ALASKA
David A. Guinn, Graduate Research Assistant
Mark A. T\imeo, Associate Professor
Environmental Quality Engineering Program
University of Alaska Fairbanks, Alaska 99775
Joan F. Braddock, Assistant Professor
Institute of Arctic Biology
University of Alaska Fairbanks, Alaska 99775
INTRODUCTION
Background
A temporary wood treatment site located at the University of Alaska Fairbanks (UAF) Palmer
Research Farm, Point MacKenzie Agricultural Project was operated during the summer months
of 1988-1989. An undefined mixture of diesel fuel, creosote, and pentachlorophenol (PCP) was
used in the process. Approximately 75 m3 (98 yd3) of soil were contaminated with up to 13.5
ppm PCP, creosote, and 13,000 ppm diesel range hydrocarbons. The Alaska Department of Environmental Conservation (ADEC) established clean-up levels of 0.5 ppm for PCP, and 1000 ppm
for diesel range hydrocarbons. The contaminated soil was excavated and stored on site in lined
cells pending selection and implementation of a remediation method.
Physical and chemical treatment options for soil contaminated with xenobiotic compounds in
the Lower 48 United States are often not available or economical in Alaska. The expense of shipping contaminated soil outside the state for treatment, difficulties in supporting complex remediation technologies in remote locations, and concerns over long-term liability associated with
landfilling make biological treatment, when feasible, a compelling option in Alaska. Therefore, it
was determined that studies should be conducted to address the feasibility of bioremediating the
Pt. MacKenzie soil.
Literature Review
The feasibility of biological treatment of soil and water contaminated with petroleum hydrocarbons is well established. The ability of native microbial consortia to degrade xenobiotic compounds when induced by exposure to those compounds has also been demonstrated.1 Unfortunately, claims regarding the potential for biodegradation of xenobiotic compounds have often
been exaggerated.2 The complex nature of interaction between target compounds, microorganisms, and environmental factors (e.g., soil type, moisture, temperature) makes extrapolating results from one system to another difficult. In practice, each site should be studied individually to
determine the feasibility and practicality of using bioremediation. A review of the Environmental
Protection Agency's (EPA's) VISITT database3 of innovative treatment technologies lists numerous vendors' claims of successful bioremediation of recalcitrant compounds, but supporting documentation often does not exist or is withheld for commercial reasons.
The feasibility of bioremediation of soil and water contaminated with PCP and creosote has
been studied with mixed results. Piotrowski4 reported successful full-scale implementation of
bioremediation for clean-up of a Superfund site contaminated with PCP and creosote. In contrast,
Mueller et al.5,6 found that biodegradation of PCP in contaminated soil and sediment was not effective during bench-scale solid- and slurry-phase studies. Sparrow and Sparrow7 found that soil
50th Purdue Industrial Waste Conference Proceedings, 1995. Ann Arbor Press. Inc.. Chelsea. Michigan 48118.
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