Energy futuresCleaning toxins from the oilsands
Oilsands development uses a vast amount of water and even though it’s recycled multiple times, the recycling concentrates the toxins and metals leftover from extracting and upgrading the bitumen, resulting in controversial tailings ponds that are a significant risk to the environment; scientists offer a way to make oilsands exploitation cleaner
Oilsands development uses a vast amount of water and even though it’s recycled multiple times, the recycling concentrates the toxins and metals leftover from extracting and upgrading the bitumen, resulting in controversial tailings ponds that are a significant risk to the environment.
Two years into a research project between biologists at the University of Calgary and engineers at the University of Alberta both groups say they are excited about their progress. A paper into the first round of research will be published in the January edition of FEMS Microbial Ecology.
A University of Calgary release reports that much of the research into tailings remediation has focused on microbes and their ability to settle the tailings sludge and clean the water. This Natural Sciences and Engineering Research Council of Canada (NSERC)-funded research is focused on a certain kind of bacterial growth called biofilms. Biofilms are everywhere in our environment, including in the plaque on our teeth and they can be very resilient, says Raymond Turner, a professor in the biological sciences department.
“We’ve isolated biofilms that are indigenous to the oilsands environment and are highly tolerant to the stress associated with toxins and metals found in tailings water. Those consortia of biofilms are able to, slowly, detoxify the water,” says Turner, who co-leads the project with Howard Ceri, a biological sciences professor.
A sample of sediment, or sludge, was taken from a tailings pond in the summer of 2009. MSc candidate and paper co-author Susanne Golby was able to cultivate biofilms from the sample under a variety of different conditions.
“It was really exciting when we found that multiple different species could be recovered within one biofilm. By altering the growth conditions, and exposing the biofilms to different stressors, we could select for or against certain species and we began to learn how we could manipulate the biofilms to get the metabolic activities and characteristics we were looking for.”
The release notes that Turner and his team are actively growing biofilms on the support material to test in bioreactors, which are being developed by professors and their graduate students in the civil and environmental engineering department at University of Alberta.
The ultimate goal, says Turner, is to develop tailings water treatment plants for all the oilsands operations. “The plant would take all tailings water, completely clean it, and return it to the river system. Just like wastewater in Calgary is cleaned and returned to the Bow River.”
