Bacteria cleans up contaminated groundwater
UNSW researchers have shown they can safely destroy hazardous industrial toxins in groundwater arising from PVC plastic production by injecting naturally occurring bacteria into a contaminated Sydney aquifer – an Australian first that raises hope of cleaning up this and similarly polluted sites around the country.
The trial has confirmed the bacteria's natural ability to degrade and clean up chlorinated solvents that leaked many years ago from a former ICI Australia chemical plant into the Botany Sands Aquifer, creating large plumes of contaminated groundwater.
ICI's successor, Orica Australia Pty Ltd, presently pumps out the contaminated water to prevent the plumes from spreading and entering Botany Bay. That water is then piped to a special treatment plant for decontamination. No other feasible option has been available.
"With present technology, it was expected that it might take decades or perhaps centuries before these toxic solvents are removed from the aquifer," says research team leader Associate Professor Mike Manefield, a Future Fellow in the UNSW School of Biotechnology and Biomolecular Sciences and Deputy Director of the Centre for Marine BioInnovation.
"Our tests showed that these bacteria effectively breathe these pollutants the way we breathe oxygen. It's a big step forward. These cultures represent a greener and cheaper tool we can use to clean up some of our contaminated sites. They have not previously been available in Australia. The real appeal is that they’re Aussie bugs."
Large volumes of the bacteria grown in beer kegs showed they thrived on a variety of diets, including ethanol, glucose and emulsified vegetable oils.
The team will soon publish technical details of the discovery of these cultures and has received $1.14 million in funding from industry and the Australian Research Council to carry out a large-scale biological remediation of groundwater at Botany and Altona in Victoria.