Microbes for Quick Clean Up of Toxic Byproducts from Heavy Crude and Oil Sands
07 September 2009
Microbiologists from the University of Essex, UK are exploring the use of microbes to break down and remove toxic compounds from heavy crude and oil sands. These acidic compounds persist in the environment, taking up to 10 years to break down. Richard Johnson, presenting his PhD research to the Society for General Microbiology’s meeting at Heriot-Watt University, Edinburgh, described how, by using mixed consortia of bacteria, they have achieved complete degradation of specific compounds in only a few days.
With dwindling supplies of high quality light crude oil, oil producers are looking towards alternative oil supplies such as heavy crude oils and abundant super heavy crudes like oil sands. However, the process of oil extraction and subsequent refining produces high concentrations of toxic byproducts.
The most toxic of these are mixtures of predominantly cycloaliphatic or alicyclic carboxylic acids known as naphthenic acids (NAs). NAs are resistant to breakdown and persist as pollutants in the water used to extract the oils and tar. This water is contained in large settling or tailing ponds. The number and size of these settling ponds containing lethal amounts of naphthenic acids are growing daily—it is estimated that there is around one billion m3 of contaminated water in Athabasca, Canada, alone—and is still increasing.
The chemical structures of the naphthenic acids we tested varied. Some had more side branches in their structure than others. The microbes could completely break down the varieties with few branches very quickly; however, other more complex naphthenic acids did not break down completely, with the breakdown products still present. We are now piecing together the degradation pathways involved which will allow us to develop more effective bioremediation approaches for removing naphthenic acids from the environment.
—Richard Johnson
Resources
Richard Johnson, Ben Smith, Steve Rowland and Corrinne Whitby (2009) A micro solution to a mega problem—can microbes be used to clean up dirty oil? (Society for General Microbiology Autumn Meeting, 7 Sep 2009)
How long and how much would it cost** to treat one + billion M3 from the Alberta tailing ponds? The content of the tailing ponds could probably double every 3 or 4 years if extraction is increased as planned.
** a special clean-up fund could be set up (with increased Royalties) for that purpose.
Could the recuperated chemicals pay for part of the clean up cost?
Posted by: HarveyD | 07 September 2009 at 08:33 AM