Adsorption of Copper, Chromium, and Arsenic from Chromated Copper Arsenate (CCA) Treated Wood onto Various Adsorbents

Substantial progress has been made in remediation of preservative treated waste wood by chemical extraction with several mineral and organic acids and biodegradation using bacteria and fungi in recent years. Non-conventional low-cost adsorbents are used to bind the metal ions in extremely stable complexes in heavy metal contaminated soils or polluted waters and thus to remediate such substrates. In this study, various adsorbents from industrial and agricultural processes were evaluated in removal of copper, chromium, and arsenic from chromated copper arsenate (CCA)- treated wood by using batch extracting experiments. Most adsorbents used in the study had the potential to remove copper ele- ment from CCA-treated wood, while chromium was the most resistant element against removal in most cases. In general, as amount of adsorbents in the extraction process and extraction duration increased, the percentage of elements removed increased. The adsorbents used in the study could be important in the remediation of wood treated with organic or water- borne wood preservatives containing copper since the use of the adsorbents is one key to unfix copper from treated wood treated.