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New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood

Informally Refereed

Abstract

Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the possible complexation of acetic/oxalic acid in the organic phase, the decomposition of oxalic acid in acetic acid at high temperatures, and the promotion of the formation and precipitation of the copper oxalate by phosphoric acid may induce an antagonistic effect which adversely influenced the effectiveness of the copper extraction. It was found that the addition of acetic acid into phosphoric acid enhanced the chromium recovery rate of the mixed acid solution. This synergistic effect of mixed acetic acid and phosphoric acids is considered one of the most interesting and significant discoveries in the study.

Keywords

Binary acid solution, CCA-treated wood, microwave extraction

Citation

Shupe, Todd F.; Hse, Chung Y.; Pan, Hui. 2012. New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood. In: Proceedings of the 55th International Convention of Society of Wood Science and Technology. AP2-2. August 27-31, 2012. Beijing, China. 1-8.
https://www.fs.usda.gov/research/treesearch/41890