COMPARISON OF COPPER LEACHING FROM ALKALINE COPPER QUAT TYPE-D TREATED CHINESE FIR AND MONGOLIAN SCOTS PINE AFTER DIFFERENT POSTTREATMENTS

Chinese fir (Cunninghamia lanceolata Hook) and Mongolian Scots pine (Pinus sylvestris Linn vat mongolica Litv) sapwood were treated with alkaline copper gum type D (ACQ-D) solutions at two concentration levels (0 5 and 11%) followed by three posttreatments oven-drying, conditioning in a humidity chamber, or exposed to hotline water The effects of treatment on copper leaching from ACQ-D-treated wood were investigated by performing tests according to AWPA E11-06 Analysis of chemical composition and pH values were determined to evaluate the effects of wood species on copper leaching The results showed that copper leaching I mm ACQ-D-treated Mongolian Scots pine without posttreatment was lower than that of treated Chinese fir However, after posttreatment. more copper leaching was observed from ACQ-D-treated Mongolian Scots pine than Chinese fir For example, after conditioning posttreatment, the percentage of copper leached from 11% ACQ-D-treated Chinese fir decreased 58 6 to 1 8%. while for Mongolian Scots pine, it decreased 49 5 to 19 4% The difference was considered to be related to different chemical compositions and pH levels