Bioremediation Approaches and Tools for Anaerobic Benzene Remediation
BTEX compounds and other aromatic hydrocarbon compounds typically degrade faster under aerobic conditions than in anaerobic systems. Hydrocarbon contaminated aquifers are often anaerobic meaning that aerobic bioremediation is not always feasible and anaerobic approaches may be required. To meet this need, anaerobic enrichment cultures capable of complete degradation of benzene, toluene and xylene have been developed at the University of Toronto. These cultures have recently been characterized and key organisms involved in the process have been identified. Furthermore, anaerobic degradation of benzene and other aromatic hydrocarbons can be enhanced through the injection of (non-oxygen) electron acceptors such as commercially available sulfate solutions.
SiREM, the University of Toronto and Federated Cooperatives Limited are currently engaged in a three-year Genome Canada funded project to move anaerobic benzene degradation from the lab to the field. The objectives of the project include scale-up of an anaerobic benzene bioaugmentation culture to field application volumes, demonstrating its effectiveness for bioaugmentation in laboratory treatability studies and ultimately testing the culture in field pilot tests. The culture is currently being assessed for bioaugmentation using microcosms constructed with materials from contaminated hydrocarbon field sites. Information provided from this testing will include inoculum density requirements, degradation rates and the range of geochemical conditions for optimal performance of the process which will be used to design upcoming field pilot trials. Molecular tools to track key microbes and functional genes are also being developed. This presentation will focus on the scale up and performance of the culture in laboratory treatability studies and discuss lessons learned to be applied to upcoming field applications.