Rapid microwave-assisted acid extraction of metals from chromated copper arsenate (CCA)-treated southern pine wood
The effects of acid concentration, reaction time, and temperature in a microwave reactor on recovery of CCA-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from chromated copper arsenate (CCA)-treated southern pine wood samples with three different acids (i.e., acetic acid, oxalic acid, and phosphoric acid) was investigated using in microwave reactor. Oxalic acid was effective in removing 100% of the chromium and arsenic at 160°C and 30 min., and acetic acid could remove 98% of the copper and arsenic at the same conditions. Oxalic acid greatly improved the extraction efficiency of arsenic and chromium when time was prolonged from 10min. to 30min. Acetic acid also showed improved ability to remove arsenic and copper when the reaction temperature was increased from 90°C to 160°C.