White Rot Fungus
White rot fungus is a bioremediation technology. Wood-rotting enzymes in white rot fungus degrade a variety of pollutants. Treatment involves mixing soil with fungus and a suitable substrate such as wood chips. White rot fungus has been tested in situ (i.e., in place) and in an above-ground bio-reactor. Moisturized air on wood chips is used in a reactor for biodegradation. This system is similar to composting, except that white-rot fungus works best in a nitrogen-limited environment.
Limitations and Concerns
High contaminant concentrations and heavy metals in the soil may be toxic to the fungus. The degradation of contaminants may not be sufficient to meet cleanup levels. Low ambient temperatures can decrease biodegradation rates. Competition from native bacterial populations and sorption of the contaminant may limit effectiveness. Fungi are susceptible to water stress. Little is known of the ability of the white rot fungus to compete with other forms of fungi.
White rot fungus has the ability to degrade a number of pollutants in soil and sediment, including the predominant conventional explosives, DDT (dichlorodiphenyltrichloroethane), polynuclear aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). In one instance, it was used to degrade dioxin in the soil.
Technology Development Status
This technology has been known for approximately 20 years with very few, if any, commercial applications. A pilot-scale study was conducted at Bangor Naval Submarine Base, Washington using white rot fungus at a former ordnance open burn/open detonation area. The degradation of trinitrotoluene (TNT) was 41%, which did not meet the cleanup goals.
Other Resources and Demonstrations
See http://ehpnet1.niehs.nih.gov/docs/1993/101-3/innovations.html for additional information.
See http://www.japanfs.org/en/pages/026523.html for the biodegradation of dioxin.
See http://www.clu-in.org/characterization/technologies/exp.cfm for a technical description of explosives in different media and the use of some analytical techniques.
See https://ert2.navfac.navy.mil/printfriendly.aspx?tool=energeticconstituents for the sampling of energetic constituents.