Effects of wood species and retention levels on removal of copper, chromium, and arsenic from CCA-treated wood using sodium hypochlorite

Chemical extraction, bioremediation, and electrodialytic processes have been extensively studied for removal of copper, chromium, and arsenic from wood treated with chromated copper arsenate (CCA). However, one problem has not been addressed: the effects of wood species and retention levels on remediation efficiency. The objectives of this study were to investigate the effects of wood species and retention levels on removal of copper, chromium, and arsenic from CCA-treated wood samples using sodium hypochlorite. Our results showed that sodium hypochlorite (NaOCl) was very effective for removal of copper, chromium, and arsenic from CCA-C treated milled wood samples for all three species used in this study. The Cu, Cr, and As extraction efficiencies for red pine were 95 % Cu, 97 % Cr and 94 % As, for maple were 95 % Cu, 97 % Cr, and 98 % As at 4.0 kg m(-3) retention levels, and for aspen were 95 % Cu, 92 % Cr, and 91 % As at 9.6 kg m(-3) retention level, respectively. However, the results showed that wood species and initial retention levels of CCA-treated wood products played very important roles in terms of removal of Cu, Cr, and As.