Fungal biodegradation could be employed as a pretreatment method to alleviate problems caused by landfill disposal of CCA-treated wood wastes (e.g. a shortage of landfill space and a release of leacheate). It could be used to decrease the volume of waste and to remove metals from waste simultaneously. We have screened hundreds of decay fungi, including fungi isolated from CCA-treated wood in service, in search of the CCA-tolerant fungal isolates. The decay capacity of the tolerant isolates was determined by the AWPA method, and the amount of CCA components removed during decay process was also investigated. A total of five isolates was confirmed that they have notable capacity to degrade treated wood and to remove CCA components. Among them, Crustoderma sp. KUC8611 effectively decayed treated wood causing mass loss of up to 60%. Biodegradation with F. palustris showed extensive leaching of chromium trioxide and arsenic pentoxide (up to 77%), but only moderate leaching of copper oxide (up to 32%). It was confirmed that these high removal capacity of chromium trioxide and arsenic pentoxide had high logarithm regression relationships with oxalic acid produced in decayed wood. In this paper, we discuss the potential of fungal biodegradation of CCA-treated wood wastes based on our relevant research results.

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