Period Covered by Report: April 4, 2003 to July 3, 2003
Date of Report: July 4, 2003
EPA Grant Number: R82-7015-010
Title: A Continuation: Humate-Induced Remediation of Petroleum Contaminated Surface Soils
Investigators: Mark A. Nanny, R. Paul Philp and Vlad E. Andrus
Institution: University of Oklahoma
EPA Project Officer: Bala Krishnan
Project Period: September 4, 2002 to September 3, 2003
Project Amount: $133,136
Research Category: Bioremediation of oil spills
The objectives of this proposed research are: 1) to measure the biodegradation and bioavailability of 14C-labeled pentadecane 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.
Pilot-scale ex-situ experiment was implemented at the Waggoner site with the help of Waggoner Estate personnel. Totally, 20 windrows consisting of four types of soil (pristine, gasoline- , diesel fuel-, and crude oil- contaminated) were deployed. Windrow's size is approximately 9.5 x 3 x 1ft. Five windrows for each type of soil represent control windrow, a humate-added windrow, a fertilizer-added windrow, a humate & fertilizer- added windrow, and microbial activity inhibitor-added windrow. Samples were collected twice: time 0 and 30 days in amount of 120 samples each time. At each sampling time, three ~200 g samples from the surface and three ~200 g samples from the subsurface of each windrow were sacrificed. Selected samples are in process of Soxhlet extraction to isolate DCM-MeOH soluble hydrocarbons. Microcosm experiment is also currently in progress. Two sets of duplicate samples (56 microcosms in each set) for 2 and 3 months were sacrificed and are in process of extractions for GC and GCMS analyses. Selected data of GCMS analyses of diesel fuel- and gasoline contaminated soils demonstrate certain diversity in compositions of extracted hydrocarbons. At present, we are in a process of determining if this is a result of heterogeneity of contaminated soils itself, or a consequence of sorption and/or biodegradation effect in presence of humate and/or fertilizer. Currently we are also conducting set of experiments to estimate the impact of humate on biodegradation and sorption vs. bioavailability of 14C-labeled octadecane (substituted for 14C-pentadecane) using Fusion Geophysical personnel and facility.
To continue scheduled sampling at Waggoner site windrows and microcosms for the next six months. To continue Soxhlet extraction and GC/GCMS analyses of microcosm extracts. To start Soxhlet extraction and GC/GCMS analyses of field sample extracts. To measure the biodegradation and bioavailability of 14C-labeled octadecane adsorbed to humate.
Humate, gasoline, diesel fuel, crude oil, microcosm, windrows, 14C-octadecane.