Ethanolamine and glycol biodegradation: From detection to remediation

Bioremediation technology design requires in depth knowledge about biotic and abiotic processes involved in contaminant evolution. The development of adequate detection methods for target contaminant and degradation products provides the fundamental information for further investigations.;Alkanolamines and glycols are used in various industrial and commercial applications. Alkanolamines are utilized as surfactants, process chemicals and pharmaceuticals. Glycols can be found in deicing fluids, as surfactants and process chemicals. These compounds were introduced into subsurface and groundwater environments in the past. Both contaminants and breakdown products may pose a threat to the environment.;This study involves the detection and degradation of ethanolamine, ethylene glycol, triethylene glycol and the breakdown products.;The developed analytical tools for the detection of ethylene glycol, triethylene glycol and their degradation products demonstrated successful, accurate and precise analyses of both laboratory and field samples. Specifically, ion exchange and ion exclusion chromatography were employed for ground water and laboratory slurry sample analyses. Optimized instrument conditions resulted in qualification and quantification of ethanolamine, ethylene glycol and triethylene glycol. Also major cations and anions were detected using the presented methods. An optimized extraction protocol involving potassium hydroxide extraction resulted in the determination of total ammonium and ethanolamine concentrations in water-soil mixtures.;Two degradation studies in aerobic and anaerobic environments investigated biodegradability and abiotic pathways of ethanolamine, glycol and degradation product evolution.;Aerobic mineralization of ethanolamine, glycols and breakdown products was achieved using bioreactors. Complete nitrogen removal was accomplished using sequential aerobic and anaerobic conditions. Aerobic conditions facilitated ammonium nitrification and subsequent anaerobic conditions allowed nitrate denitrification finally completing the nitrogen cycle. Abiotic mechanisms, such as ammonia volatilization were identified to contribute significant contamination reduction in open slurry reactors. The symbiosis of biotic and abiotic processes was identified to contribute to the overall contamination reduction. A conceptual working model of ethanolamine and glycol evolution in bioreactors is presented.;An active dewatering and bioventing program was employed at a decommissioned sour natural gas plant site. Ethanolamine and glycol contamination was detected on-site. This study presents concentration changes due to active remediation. A conceptual model of the field conditions and proposed fate and transport processes are discussed.;This study presents a full program consisting of developing detection protocols for contaminants, investigating biodegradation of the contaminants in laboratory reactors and transferring the findings into an active field remediation program.