[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2014/07/EW-07-11-14-Cleaning-Up-with-Fungus.mp3|titles=EW 07-11-14 Cleaning Up with Fungus]
Dealing with contaminated soils in industrial and former industrial sites is a continuing problem for society. People employ a variety of methods for removing or remediating persistent organic chemicals in these places. Techniques such as capping, excavation, and even incineration have all been used at one point or another. All the methods have their problems and most are quite expensive.
Recently, research at a university in Finland has discovered a new technique based on the use of White rot, a common fungus that decays fallen trees in forests. In trials with the fungus, 96% of poly-aromatic hydrocarbon compounds (PAHs) were broken down after three months. PAHs are chemicals that are formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances like tobacco or charbroiled meat. Similarly, 64% of the dioxins in contaminated soils broke down and these highly toxic compounds only break down very slowly under natural circumstances. While composting can break down simple organic pollutants, such as oil, PAHs and dioxins are much harder to deal with and are often transported to landfill sites or incinerated.
The White rot fungus is initially grown on pine bark, and after several weeks, the fungal culture is transferred to the contaminated soil in a temperature-controlled treatment plant where it works on breaking down the toxic materials. This bioremediation technique could be used for other enduring organic pollutants as well. The method nature uses to recycle forests may be the best way to clean up some of society’s nastiest messes.
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Fungi clean contaminated soils
Photo, posted November 11, 2007, courtesy of Peter Van den Bossche via Flickr.
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