ASSESSMENT OF THE SUBSURFACE FATE OF MONOETHANOLAMINE

Sorensen, James A. ; Gallagher, John R. ; Kays, Lori G.

University of North Dakota

关键词: Aerobic Conditions;    Research Programs;    Attenuation;    Oxygen;    Bioremediation;   

DOI  :  10.2172/824931
RP-ID  :  NONE
RP-ID  :  FC26-98FT40321
RP-ID  :  824931

美国|英语

来源: UNT Digital Library

【 摘 要 】

Burial of amine reclaimer unit sludges and system filters has resulted in contamination of soil at the CanOxy Okotoks decommissioned sour gas-processing plant with amines, amine byproducts, and salts. A three-phase research program was devised to investigate the natural attenuation process that controls the subsurface transport and fate of these contaminants and to apply the results toward the development of a strategy for the remediation of this type of contamination in soils. Phase I experimental activities examined interactions between monoethanolamine (MEA) and sediment, the biodegradability of MEA in soils at various concentrations and temperatures, and the biodegradability of MEA sludge contamination in a soil slurry bioreactor. The transport and fate of MEA in the subsurface was found to be highly dependant on the nature of the release, particularly MEA concentration and conditions of the subsurface environment, i.e., pH, temperature, and oxygen availability. Pure compound biodegradation experiments in soil demonstrated rapid biodegradation of MEA under aerobic conditions and moderate temperatures (>6 C). Phase II landfarming activities confirmed that these contaminants are readily biodegradable in soil under ideal laboratory conditions, yet considerable toxicity was observed in the remaining material. Examination of water extracts from the treated soil suggested that the toxicity is water-soluble. Phase II activities led to the conclusion that landfarming is not the most desirable bioremediation technique; however, an engineered biopile with a leachate collection system could remove the remaining toxic fraction from the soil. Phase III was initiated to conduct field-based experimental activities to examine the optimized remediation technology. A pilot-scale engineered biopile was constructed at a decommissioned gas-sweetening facility in Okotoks, Alberta, Canada. On the basis of a review of the analytical and performance data generated from soil and leachate samples, the biopile operation has successfully removed all identified amines and removed significant amounts of organic nitrogen and organic carbon. Salts initially present in the soil and salts generated during the biodegradation of contaminants remain to be flushed from the soil. Laboratory data show that these salts are readily removable with a simple soil leach.