Chemical and Biological Remediation of CCA-Treated Waste Wood

Abstract

Since common disposal options such as landfill and incineration for chromated copper arsenate CCA-treated waste wood are becoming more unacceptable, there is a need to develop alternative technologies to use CCA-treated waste wood as a potential fiber source. Chemical and biological remediations of CCA-treated waste wood are thought to be environmentally acceptable. This paper reviews the ability of chemical and microbial processes to remove chromium, copper, and arsenic elements from CCA-treated waste wood. Some researchers have explored chemical extraction using various inorganic and organic acids. Depending on several parameters, such as concentration, time, temperature, pH, particle size, etc., chemical extraction was found to be effective in removing much of the CCA from treated wood or contaminated wastes. On the other hand, bioremediation using bacteria and fungi is another possible method for removal of heavy metals from treated wood since some bacteria and fungi are extremely tolerant to toxic metals. Some copper tolerant fungi can remove some of the arsenic and chromium as well as copper. In addition, some metal leaching bacteria can be used effectively to extract concentrated heavy metal ions from treated wood