Effects Of Mineral Sorbents on Leaching and Volatilization of Arsenic, Chromium and Copper during the Disposal of CCA Treated Wood

摘要

Chromated Copper Arsenate (CCA) is a popular wood preservative applied to wood products such as utility poles and marine and freshwater docks to prevent environmental decay during outdoor use. Historically prior to 2004 it was also used to treat wood used for decks, walkways, and fences and as a result it has been the predominant wood preservative observed in the disposal sector in recent years. Due to its common use in the building industry, CCA-treated wood in many cases contaminates construction and demolition waste wood with chromium, copper and arsenic. Historically, estimates suggest that approximately 60% of CCA-treated wood waste in Florida had been burned to produce energy. Disposal of CCA-treated wood via incineration may be problematic due to the possible volatilization of metals at high temperature and leaching of metals in the ash. This poses serious health and environmental concerns. Hence methods are needed to control volatilization of the metals during the combustion process and to minimize leaching of CCA metals from the resultant ash. Recent research studies have shown the potential of injecting mineral sorbents into combustion systems for controlling heavy metals. The objective of this study is to identify mineral sorbents that can minimize volatilization and leaching of heavy metals from CCA wood under combustion conditions.