Progress 12/09/02 to 12/09/07
Outputs
Bioremediation is an alternative waste management system to landfill disposal of massive volumes of waste wood and potential leaching of toxic chemicals and metals into the environment. Methods were developed for bacterial or fungal bioremediation of waste wood treated with the EPA-banned wood preservative chromated copper arsenate (CCA). Strains of metal tolerant bacteria were identified and shown to remove some of the metals from CCA-treated wood waste. Application of oxalic acid and bacteria to CCA-treated wood was shown to remove most metals. A two-step bioremediation process for CCA-treated waste was developed in the laboratory and scaled-up in an industrial fermentor. The process is more efficient at removing metals from the wood than either acid extraction or bacterial bioleaching alone. An economical fungal bioprocessing method was developed for CCA-treated wood taken out of service. The method reduces the volume of wood waste and provides the capacity for
leaching and collecting the metals for reuse. The process includes isolating and characterizing CCA-tolerant fungi, defining economical materials and methods to prepare and package viable inoculum of metal-tolerant decay fungi, establishing treatment procedures for the remediation and degradation process, conducting laboratory scale-up to evaluate the method on solid lumber treated with CCA. High intensity x-ray methods were used for the nanoscale chemical analysis of fungal remediation of the environmental toxins, providing important information about metal transformation and chemical forms of toxins during remediation, including detection of highly reactive oxidation states of chromium and arsenic. Fungal remediation methods were similarly developed for ACQ, pentachlorophenol and creosote. Results were published in peer-reviewed journals. Seven U.S. patents were awarded for fungal remediation of waste wood treated with either CCA, ACQ, creosote or EPA-banned pentachlorophenol.
Impacts
Waste management systems; environment.
Publications
- Illman, B.L. 2006. Putting fungi to work: mycoremediation of chemically treated waste wood [abstract]. In: Eighth International Mycological Congress handbook and abstracts book 2. 2006 August 21-25; Queensland, Australia. PS7-613-0508.
- Illman, Barbara L.; Yang, Vina W. 2006. Bioremediation of treated wood with fungi. In: Townsend, Timothy G.; Solo-Gabriele, Helena. eds. Environmental impacts of treated wood. Boca Raton, FL: Taylor and Francis Group, CRC Press: 413-426, Chapter 23.
- Illman, Barbara L.; Yang, Vina W.; Ferge, Leslie A., inventors; The United States of America as represented by the Secretary of Agriculture, assignee. 2006. Fungal degradation and bioremediation system for CCA-treated wood. U.S. patent 6,972,169 B2. 2005 December 6. Int. Cl. A01N 63/00; U.S. Cl. 435/1.1; 435/262.5; 435/254.1; 424/93.5.
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Progress 10/01/04 to 09/30/05
Outputs
Research was moved to another research work unit in late FY 2004 with the transfer of two positions, a scientist and a professional support position.
Impacts
Impact of the research will be reported elsewhere. A new Research Work Unit Description without Problem Area 3 will be drafted in 2006.
Publications
- No publications reported this period
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Progress 10/01/03 to 09/30/04
Outputs
Concerns about indoor air quality due to mold growth have increased dramatically in the United States. In the absence of proper moisture management, fungicides need to be developed for indoor use to control mold establishment. An ideal fungicide for prevention of indoor mold growth on wood-based materials needs to specifically prevent spore germination and provide long-term protection under conditions of high humidity. Fungicides intended for indoor use must be nontoxic, nonvolatile, odorless, and hypoallergenic. Multicomponent systems were tested in AWPA soil block tests for inhibition of brown-rot and white-rot fungi, and ASTM standard tests for inhibition of mold fungi and termites. Multicomponent biocide systems combining a borate-base supplemented with voriconazole or thiabendazole, and either thujaplicin, or ethanolamine performed well against two brown-rot fungi, Coriolus versicolor, three mold fungi, Aspergillus niger, Penicillium chrysogenum, and Trichoderma
viride, and the subterranean termite, Reticulotermes flavipes (Kollar). We conclude that a multicomponent biocide system containing Bor-A+ supplemented with azoles and either ethanolamine or thujaplicin can protect wood from decay fungi, mold fungi, and termites for interior applications.
Impacts
Research is conducted on the growing problems associated with mold fungi affecting air quality in buildings nationwide. The results will lead to better mold detection which is the first step required for inspecting buildings for putative mold problems, will determine conditions for mold establishment in buildings, and will lead to better mold prevention.
Publications
- Clausen, Carol A.; Yang, Vina W. 2004. Multicomponent biocide systems protect wood from decay fungi, mold fungi, and termites for interior applications. In: Thirty-fifth annual meeting of the International Research Group on wood preservation; 2004 June 6-10; Ljubljana, Slovenia. Stockholm, Sweden: IRG Secretariat; IRG/WP 04-30333. 7 p.
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Progress 10/01/02 to 09/30/03
Outputs
Determined efficacy of chemical groups (wood preservatives, food preservatives, plant extractives, pharmaceuticals, mixtures of these chemicals) to kill mold fungi on pine wood.
Impacts
Research is conducted on the growing problems associated with mold fungi affecting air quality in buildings nationwide. The results will lead to better mold detection which is the first step required for inspecting buildings for putative mold problems, will determine conditions for mold establishment in buildings, and will lead to better mold prevention.
Publications
- Clausen, Carol A.; Yang, Vina W. 2003. Mold inhibition on unseasoned southern pine. In: Thirty-fourth annual meeting of the International Research Group on wood preservation; 2003 May 18-23; Brisbane, Australia. Stockholm, Sweden: IRG Secretariat; IRG/WP 03-10465: 9 p.
- Yang, V.W.; Clausen, C.A. 2003. Inhibition of mold growth by bacteria in liquid culture [poster abstract]. In: SIM Annual meeting program and abstracts; 2003 August 10-14; Minneapolis, MN. Fairfax, VA: Society for Industrial Microbiology. P105: 104.
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