Remoção de elementos tóxicos em efluente proveniente da descontaminação de madeira tratada com arseniato de cobre cromatado

Abstract

The use of inorganic preservative CCA (chromated copper arsenate) for wood preservation has been an alternative to increase its durability therefore generate large volumes of wastewater, either in plants as in -decontamination processes of the treated wood. The elements Cu, Cr and As are toxic components present in the CCA and, according to Brazilian environmental legislation, the effluents of any productive activity can only be discharged, if they comply with the emission standards stipulated. Thus, the main objective of this work was to develop a method for the treatment of effluent generated from the decontamination of CCA-treated wood, which evaluated the total precipitation of Cu, Cr and As and Cu electrowinning, processes studied were used in wastewater treatment of different wood species (Eucalyptus spp e Pinus resinosa). With the methodologies developed above was possible to obtain percentage of 98.5 % total removal of elements using 1,180 mg L-1 of Fe (III) and Ca(OH)2 for pH adjustment . It was possible to recover about 91% of Cu in the effluent when it applied a current of 5 A for 90 min, utilizing anodes and cathodes of stainless steel (AISI 302). The results showed that treatments proposed for effluent from CCA-treated wood were satisfactory, at the end of the process it was obtained a a suitable effluent for disposal in accordance with the emission standards set by federal and state environmental laws