The overall objective of this project is to study the possible positive effect of organic matter in the remediation of brine-impacted soil. The efficacy of this treatment will be quantified in a field study conducted in the Tallgrass Prairie Preserve in Osage Co., Oklahoma and in a companion microcosm study at the University of Tulsa. The microcosm study will attempt to identify the mechanism or mechanisms of action of the organic matter, which include: 1) a strictly physical effect on the texture of the soil; 2) an enhancement of the cation exchange capacity of the soil; 3) an enhancement of the water-stable aggregates formed from organic matter and soil mineral particles. Given that the all three of these mechanisms are affected by microbial action on the hay, the microbial populations will be determined both qualitatively and quantitatively, and then correlated with the results of the field and laboratory studies.
Both microcosms and field sites are running. The field sites were sampled and tilled at the end of September. The microcosms were sampled at the end of September and November. The microcosms were not sampled at the end of October because the International Petroleum Environmental Conference was during the time the samples would have been processed.
Kim Carter gave an oral presentation of our results at the 8th Annual International Petroleum Environmental Conference.
The main result to date is that the hydraulic conductivity is higher in the plots and microcosms that have received hay. We cannot tell yet if this has helped the leaching of brine components from the soil.
Kim Carter, Brooke Mason, Laura Ford, Thomas Harris, and Kerry Sublette, The Use of Hay in the Remediation of Oilfield Brine-impacted Soil, 8th Annual International Petroleum Environmental Conference, November 2001.
The field sites will be sampled and tilled at the beginning of January. The microcosms will continue to be sampled and tilled on a monthly basis.
Thomas Harris will be leaving the University of Tulsa for an industrial position at the end of 2001. Estelle Levetin, Department of Biological Sciences, University of Tulsa, will be joining the project.
Supplemental Keywords: produced fluids, brine, organic matter, permeability, hydraulic conductivity, cation exchange capacity, aggregate stability, bioremediation, microcosm, field study