Effects Of Wood Species And Dimensions On Cooper Leaching From ACQ-D Treated Wood

In this study, Chinese fir (Cunninghamia lanceolata Hook.) and Scots pine (Pinus sylvestris Linn.var.mongolica Litv.) samples with two dimensions (19mm×19mm×450 mm,19 mm×19 mm×19 mm) were vacuum-pressure treated with ACQ-D wood preservatives with two concentrations (0.5% ACQ-D,1.1% ACQ-D) and post-treated with two hot air post-treatments in the drying oven (70℃,R.H.80%,24 h) and in the conditioning chamber (70℃,R.H.80%,24h),, and hot water post-treatment in hot water bath(110℃,24h) respectively to accelerate the fixation rate of copper. In order to compare the effects of wood species and dimensions on copper leaching from ACQ-D treated wood, samples were performed the leaching test according to AWPA E11-06. The results of this study were summarized as follows:1. Copper leaching from ACQ-D treated wood would be influenced by many factors, including wood species, copper retentions, wood components in different species, the ratio between wood surface and volume and different post-treatment conditions. Sample dimensions play a critical role on copper leaching. Generally, More copper would be leached out from the treated wood with small dimensions.2. Wood species would play different roles on copper leaching from ACQ-D treated wood with different post-treatments. More extractive contents in Mongolian Scots pine is helpful for improving the leaching resistance of the treated wood without any post-treatment. However, after some post-treatments, ACQ-D treated Chinese fir would obtain better copper fixation quality, which has more fixation sites such as the higher contents of lignin.3. There was no big difference between X-ray fluorescence (XRF) and atomic absorption spectrophotometry (AAS) in determining the content of active ingredients in ACQ treated wood. But XRF method has many advantages including the faster determination rate, higher precision in analysis and easier operation.