Tert-Butyl Alcohol (TBA) Biodegradation by a Mixed Bacterial Culture YZ1 Enriched from Granular Activated Carbon (GAC)

Student Presenter

Yang Zhang, Department of Civil and Environmental Engineering, Civil Engineering Building, Rm 4160, 205 North Mathew Street, University of Illinois, Urbana, IL 61801, Tel: 217-898-4214, Email: zhan33@uiuc.edu
Xiaomin Yang, Atlantic Richfield Company, BP Mail Code 2N, 28100 Torch Parkway, Warrenville, IL 60555, Tel: 630-836-7176, Email: Xiaomin.Yang@bp.com
Kevin T. Finneran, Department of Civil and Environmental Engineering, Civil Engineering Building, Rm3230, 205 North Mathew Street, University of Illinois, Urbana, IL 61801, Tel: 217-244-7956, Email: finneran@uiuc.edu

Tert-Butyl Alcohol (TBA) is a groundwater contaminant that is miscible in water and adsorbs poorly to aquifer solids; therefore pump and treat is the strategy employed near drinking water sources. Unlike other organic contaminants, air stripping and adsorption technologies are relatively inefficient for TBA. TBA biodegrades under aerobic conditions and cultures that develop within granular activated carbon (GAC) reactors are used as the primary TBA removal mechanism in a technology dubbed “Bio-GAC”. A TBA degrading enrichment culture was developed from GAC material (YZ1 – this culture has unique metabolic properties from KR1, enriched from the same GAC material)to 1.) quantify TBA degradation kinetics under changing reactor conditions, to 2.) serve as an inoculum for GAC reactors in which native TBA degrading communities do not develop, and 3.) test low biomass versus high biomass inoculation strategies. Data suggests that mineralization of TBA in resting cell suspensions is fast, with up to 100% of the TBA mineralized to CO₂ within 80 hours. What’s more, culture could be starved for 7days without losing TBA degradation ability. Growing cultures continuously degrade 5mM TBA within 5 days; however, kinetics are slow relative to the resting cell suspensions, which may allow TBA breakthrough during periods of increased pumping in field reactors. The culture degraded TBA at extreme temperatures, 4℃ and 60℃, which implied its application to cold groundwater. The culture is alkaliphile. The culture grows readily in freshwater media; the culture also adapted to high phosphate media, which is useful for agricultural areas where phosphate concentrations are high in TBA-contaminated groundwater. TBA was the sole electron donor and carbon source. These data will be used to develop a TBA-degrading bio-GAC reactor for wellhead treatment that can maintain activity during environmental fluctuations or changing (high versus low biomass) inoculation strategies.

Top