REMEDIATION OF BRINE SPILLS WITH HAY, YEAR 2
Laura Ford
Shailendra Singh*
Kimberly Carter
Kerry L. Sublette
University of Tulsa
Department of Chemical Engineering
600 S. College Ave.
Tulsa, OK 74104
Voice: 918-631-2227
Fax: 918-631-3268
E-mail: laura-ford@utulsa.edu
Kathleen Duncan
University of Oklahoma
Norman, OK
The field demonstration of the IPEC project "Remediation of Brine Spills with Hay" has been running for two full years and a third summer. In the first year of this project, we set up a field demonstration to treat two produced fluids spill sites and a control site with four different soil amendments to determine the effectiveness of hay as a soil amendment for brine spills. Our four soil treatments are tilling, tilling with hay, tilling with fertilizer, and tilling with hay and fertilizer. Eight microcosms were built to treat contaminated soil with the same soil amendments and provide controlled watering and aeration. The microcosms were operated for only the first year. The field sites and microcosms were sampled regularly during the first year to track changes in concentrations of brine components, soil properties, and microbial populations to determine the mechanism(s) by which remediation occurs. First year results indicate that the first proposed mechanism is probably active: the hay provided physical openings in the soil and increased the hydraulic conductivity. The second proposed mechanism, increased cation exchange capacity from decay products of organic matter, does not appear to be active. Neither is the third proposed mechanism, increased wet aggregate stability from compounds formed during the decay of the hay. Microorganisms in sites and microcosms with hay were different from those without hay. Salt components decreased more in microcosms with hay than those without. Over the first year, salt components decreased most in the field sites with tilling and fertilizer, interestingly. Sampling was suspended in the field sites for the second year and started again in the third summer. The field sites were watered during the third summer to supplement natural rainfall (and correspondingly the remediation rate). Results to date for soil salt concentrations, soil properties, and microbial populations will be presented.