This study evaluates oxalic acid accumulation and bioremediation chromated copper arsenate (CCA) treated wood by three brown-rot fungi, Fomitopsis palustris, Coniophora puteana, and Laetiporus sulphureus and ten mold and staining fungi, Aspergillus niger, Aureobasidium pullulans, Gliocladium virens, Penicillium funiculosum, Rhizopus javanicus, Ceratocystis pilifera, C. peceae, Alternaria alternata, Trichoderma viride, and Cladosporium herbarum. In the study, the fungi were first cultivated in a fermentation broth in order to accumulate oxalic acid and bioremediation of CCA-treated wood was then performed through leaching of heavy metals inside the broth. F. palustris and L. sulphureus exposed to CCA-treated sawdust for 10 days caused a decrease in As of 100% and 85%, respectively however C. puteana remediation removed 18% As from CCA-treated sawdust. Likewise, Cr removal in F. palustris and L. sulphureus remediation processes was higher than those in C. puteana depending on less oxalic acid accumulation compared to F. palustris and L. sulphureus. All mold and staining fungi caused more than 70% Cu removal however Cr removal rates varied from 20% to 50%. Arsenic removal showed variations among the mold and staining fungi from 30% to 90%. These results suggest that fungal remediation processes can remove inorganic metal compounds via organic acid production increasing the acidity of the substrate and increasing the solubility of the metals.

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