EPA Grant Number: R827015-01-0
Title: A Continuation: Humate-Induced Remediation of Petroleum Contaminated Surface Soils
Investigators: Mark Nanny, R. Paul Philp, V.E. Andrusevich, Glenn Ulrich
Institution: University of Oklahoma
EPA Project Officer: Bala Krishnan
Project Period: September 4, 2002 to September 4, 2003
Project Amount: $133,136
Research Category: Bioremediation of oil spills
Abstract: This study proposes to examine and expand upon humate-induced remediation processes occurring in soils contaminated with crude oil, diesel fuel, and gasoline. Humates are high-molecular weight, natural salts of humic and fulvic acids (HA and FA), originating from the diagenesis of terrestrial, marine, and lacustrine organic matter. In our recent IPEC funding (Humate-Induced Remediation of Petroleum Contaminated Surface Soils; July 1, 2000 to June 30, 2001; IPEC 14-2-1201270-94823), we achieved our research goals by demonstrating that humate enhances the remediation of surface soil contaminated with crude oil through the combined processes of hydrocarbon adsorption and accelerated biodegradation. The efficacy of humate as a geosorbant was shown by the fact that after exhaustive dichloromethane/methanol solvent extraction, humate saturated with crude oil retained at least 10% of their mass as crude oil.
In the proposed research we will address critical questions discovered to be important based upon our recently IPEC-funded research. Biodegradation and bioavailability of hydrocarbons strongly-bound to humate must be quantitatively measured in order to determine if these strongly-bound hydrocarbons are still an environmental concern and if they can truly be biodegraded. Second, the effectiveness of humate remediation of soils contaminated with hydrocarbon products such as gasoline (including MTBE - gasoline oxygenated additive) and diesel fuel must be assessed. Finally, we need to begin transferring knowledge gained from laboratory experiments to the field.
Specifically, the goals of this proposal are: 1) to measure the biodegradation and bioavailability of 14C-labeled heptadecane that is strongly adsorbed to humate, 2) to examine the adsorption of gasoline, gasoline oxygenates as a part of gasoline itself, and diesel fuel to humates, as well as their biodegradation in soil microcosms, and 3) to assess humate-induced remediation on a pilot-scale by conducting ex-situ tests of soils contaminated with crude oil, diesel fuel, and gasoline.