Period Covered by the Report: 5-30-01 to 5-30-02
Date of Report: 6-30-02
EPA Grant Number: R827015-01-0
Title: Remediation of Brine Spills with Hay
Investigators: Laura P. Ford, Kerry Sublette, Thomas M. Harris
Institutions: University of Tulsa
EPA Project Officer: Bala Krishnan
Project Period: May 30, 2001 to May 30, 2002 (N/C Ext. to August 15, 2002)
Project Amount: $80,003
Research Category: Brine spill remediation
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.
Progress Summary/Accomplishments:
The last field and microcosm samples were taken in the middle of May. One result is that the hydraulic conductivity is higher in the plots and microcosms that have received hay. Another result is that both the cation exchange capacity and the wet aggregate stability in the microcosms seem to have peaked and then fallen off again.
We have submitted a full proposal to the Science Advisory Board for a continuation of the field portion of this project.
Publications/Presentations:
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.
Future Activities:
The field sites will be sampled in June to catch the effects of late spring rainfall. Dr. Duncan will analyze all of the microbial data when she receives it from Microbial Insights.
A mini-leaching experiment will be done on the dirt from the microcosms. The microcosms were watered enough to maintain microbial life but not enough to wash salt from the soil. Soil will be packed into the columns used for the hydraulic conductivity measurements and washed with high purity water. The "leachate" collected from the columns will be analyzed for salt concentrations in an attempt to determine if the soil amendments affect the salt removal rate.
Dr. Ford will present the findings of this project at the 9th Annual International Petroleum Environmental Conference in November 2002.
Supplemental Keywords: produced fluids, brine, organic matter, permeability, hydraulic conductivity, cation exchange capacity, aggregate stability, bioremediation, microcosm, field study