Journal article
Fungal bioleaching of metals in preservative-treated wood
Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ 85721-0011, USA
Twenty-four brown-rot and 10 white-rot fungi were screened to evaluate their applicability for detoxification of preservative-treated wood impregnated with copper and chromium (CC) salts. Brown-rot fungi generally showed higher tolerance towards copper inhibition than white-rot fungi. Additionally, brown-rot fungi were found to accumulate considerable quantities of oxalic acid (up to 44.3mM) in liquid medium, while white-rot fungi generally accumulated only traces of this organic acid.
Oxalic acid is a strong organic acid capable of complexing a variety of heavy metals. Four Antrodia vaillantii and two Poria placenta brown-rot strains that displayed both a high copper tolerance and a high oxalic acid production were selected for further study. The brown-rot fungi effectively decayed wood containing up to 4.4% CC causing corrected mass losses of up to 24.3% in 4 weeks.
Fungal treatment was also found to promote extensive leaching of chromium (up to 52.4%), but only moderate leaching of copper (15.6% or less). These results indicate the potential of solid-state fermentation with copper-tolerant fungi for the remediation of preservative-treated wood. Improving the solubility of copper will be an important challenge for future research.
Language: | English |
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Year: | 2007 |
Pages: | 798-804 |
ISSN: | 18733298 and 13595113 |
Types: | Journal article |
DOI: | 10.1016/j.procbio.2007.01.019 |