PROCESS FOR DECONTAMINATING PRESERVATIVE-TREATED WOOD AND RECOVERING METALS FROM LEACHATES

摘要

Described is a process for decontaminating wood treated with preservative such as chromium copper arsenate (CCA) including contacting the contaminated wood with water and inorganic acid at a concentration between 0.05 and 0.8 N at less than 100 °C to leach out the contaminants and then separate the wood from the solution. Also described is a process for extracting metals such as copper from a solution containing chromium, copper and arsenic, such as the leachate solution used to decontaminate CCA-treated wood, by precipitation using a coagulant at a pH favoring precipitation of arsenic and continued solubility of copper, or by ion exchange resins.