The extraction effects of acid concentration, reaction time and temperature in a microwave reactor on recovery of chromated copper arsenate (CCA)-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from CCA-treated southern pine wood samples with three different wood particle sizes (i.e., (1) 0.5 cm3, (2) 0.5x05x1.0 cm, and (3) 0.5x0.5x1.5 cm) was investigated using a microwave reactor. Experiments were performed at three reaction times (i.e., (1) 10, (2) 30, and (3) 50 min. and two levels of phosphoric acid concentration (i.e., (1) 2.5, (2) 3.5%). The recovery of all three metals at all particle sizes was significantly affected by reaction time for short reaction periods but not at long durations. As expected higher acid concentration greatly facilitated greater metal recovery rates. The recovery of chromium was much less than the other metals and the best recovery was 64.47% with an acid concentration of 3.5%, 50 min. reaction time, and 0.5 cm3 particle size. The recovery of arsenic and copper was 93.52% and 94.89%, respectively, at similar reaction conditions.

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