45    APPLICATION OF THE MICROTOX® TOXICITY
ANALYZER AS AN INDICATOR OF TREATMENT AND
REMEDIATION
John N. Veenstra, Professor
School of Civil and Environmental Engineering
Oklahoma State University
Stillwater, Oklahoma 74078-5033
Ranee T. Shields, Environmental Engineer
Oklahoma City, Oklahoma 73105
James F. Sieck, Health, Safety, Security, and Environmental Manager
Explorer Pipeline Company
Tulsa, Oklahoma 74101
OVERVIEW
There is a need for a simple, real-time, inexpensive, and reproducible method for evaluating
contamination. Traditionally, the identification and delineation of contaminants has been measured by chemical analysis to indicate the degree of pollution. The analytical results found
through chemical analysis are limited to constituent identification, neglecting other important
factors affecting the impact of contamination on human health and the environment. Further,
chemical analysis is time-consuming and becoming cost-prohibitive.
A toxicity-based approach to evaluate contamination provides a meaningful evaluation of the
impact of a pollutant on the environment due to the ability to describe the potential effect on organisms from exposure to various concentrations of chemicals. Currently, EPA-approved chronic
toxicity test methods1 are limited, due to the large expense and long turnaround time before results are available. An alternative test protocol is the Microtox® Toxicity Analyzer,* which measures the reduction in light production in a bioluminescent bacteria as it is exposed to pollution.
Two concurrent studies included the use of the Microtox to evaluate its potential to quantify
treatment efficacy. The Microtox was used to monitor contaminant reduction using composting
techniques to remediate soils contaminated with petroleum hydrocarbons. Further, the bioremediation of petroleum tank-bottom sludges was evaluated to determine if there was a correlation
between toxicity and organic content reduction.
PETROLEUM HYDROCARBON CONTAMINATED SOILS REMEDIATION
THROUGH COMPOSTING
Introduction
Many years of United States' reliance on fossil fuels has resulted in hydrocarbon contamination of soils and groundwater at thousands of sites across the country. Soil contamination at
many sites has been largely ignored or relegated to a lower priority due to the slower rate at
which soil contaminated areas expand and impact adjacent properties, as compared to groundwater contamination. The major focus of this research is on remediation of soils contaminated by
recent releases of refined petroleum products from pipelines. Accessibility, regulatory requirements, and increasing costs are driving the search for environmentally sound, cost-effective, on-
site techniques for the remediation of petroleum contaminated soils.2
'Microtox® Toxicity Analyzer is a registered trademark of Microbics Corporation.
51st Purdue Industrial Waste Conference Proceedings, 1996, Ann Arbor Press, Inc., Chelsea. Michigan 48118.
Printed in U.S.A.
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