Benzene, toluene, ethyl benzene, xylene (BTEX) and other aromatic hydrocarbons typically degrade faster under aerobic conditions than under anaerobic conditions. When hydrocarbon contaminated aquifers become anaerobic, aerobic bioremediation is not always feasible and anaerobic bioremediation approaches become favorable. To address this need, anaerobic cultures capable of complete degradation of BTX have been developed at the University of Toronto (UofT). The cultures have been characterized and key organisms have been identified.
SiREM, UofT and Federated Cooperatives Limited are currently engaged in a three-year project to advance anaerobic benzene degradation from the lab to the field, funded in part by Genome Canada and the Province of Ontario. The objectives of the project include scale-up of an anaerobic benzene culture to field volumes, demonstrating its effectiveness for bioaugmentation in treatability studies and in field tests. The culture is currently being assessed using microcosms constructed with materials from hydrocarbon contaminated sites. Information generated will include inoculum density requirements, degradation rates and the range of geochemical conditions required for optimal performance of the culture, and will be used to design field trials. Molecular genetic tools to quantify and track key microbes and functional genes involved in benzene degradation are also being developed. These tools will allow assessment and monitoring of enhanced bioremediation applications.
Jennifer Webb and Peter Dollar, SiREM, Guelph, Ontario
Elizabeth Edwards, Nancy Bawa, Shen Guo and Fei Luo, University of Toronto, Toronto, Ontario
Kris Bradshaw, Federated Co-operatives Ltd., Saskatoon, Saskatchewan