|Waste dumps turned to prime real estate|
|Thursday Aug 31 06:04 AEST
A team of Australian scientists are using bacteria to turn toxic waste dumps into prime real estate.
The researchers are targeting cancer-causing chemicals produced by industry decades ago that have been lurking in groundwater under the nation's cities for up to 50 years. The Cooperative Research Centre for Contamination Assessment and Remediation of the Environment is testing a range of methods for breaking down the underground toxins.
"Virtually anywhere there has been a fuel dump, a munitions store, an old chemical factory or heavy manufacturing plant, there is potential for toxic substances to leak into groundwater underneath," Associate Professor Megha Mallavarapu said.
"Today, with urban growth, these sites are often in the heart of our cities - prime residential real estate.
"And the water may be used to irrigate gardens and parks, sometimes for food production and even for drinking, exposing the population to a risk from the past."
The methods, which include manipulating existing bacteria or introducing new microbes to the site, avoid the high cost and risk of having to excavate or pump and treat the site.
"The preferred solution is natural attenuation, in which microbes break down the chemical into harmless fractions or in which it is diluted into insignificance," Prof Mallavarapu said.
If the pollution was particularly toxic or difficult to break down, the researchers would stimulate microbes with fertilizer or oxygen or introduce new microbes.
"With the growth in our cities, demand for remediation services is growing very fast, as new suburbs overlap old industrial areas," Prof Mallavarapu said.
"The problem is even greater in Asia, where there are literally millions of polluted sites, many of them unknown."