With the enhanced focus on the environmental impact of the preservative-treated wood in recent years, it is necessary to perform some post treatments to prevent contamination of soil and ground water and reduce copper losses from ACQ treated wood in service. In this study, the potential of hot air, hot water, steaming and microwave post treatments to accelerate the fixation of copper in ACQ-D treated Chinese fir were assessed. The results showed that: 1) all post-treatments used in this study could reduce copper leaching from ACQ-D treated Chinese fir. For hot air and hot water post treatments, the percentages of copper leached out were highly temperature and duration dependent, and were reduced significantly with increased temperature and duration. For hot air post treatment, higher relative humidity and circulation conditions accelerated copper fixation in wood. At 70°, 10h hot air post treatment at 80%R.H. with circulation conditions or 100° hot water post treatment for 9h, most of the copper in the treated wood could be fixed in the Chinese fir wood samples. However, for steaming and microwave post treatments, it seemed the duration and temperature or power level only slightly accelerated copper fixation in wood. 2) During hot air post treatments, a very small proportion of cupric copper was converted to cuprous forms at higher temperatures. However, during 100° hot water post treatments, cupric copper was quickly reduced to cuprous forms and it was highly duration dependant. The percentage of copper conversion could be more than 40% after 9h in 100° hot water. Further studies will be carried out: a) to evaluate promising conditions to improve copper leaching resistance in steaming and microwave post treatments; b) to assess the copper conversion after steaming and microwave post treatment for which better leaching resistance could be obtained.

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