The fixation of CCA-C preservative was investigated in sapwood of red pine (Pinus resinosa Ait.), trembling aspen (Populus tremuloides Michx.) and red maple (Populus tremuloides Michx.) at target retentions of 4.0, 6.4, 9.6 and 30.0 kg/m3. Treated wood sawdust was water extracted at close time intervals during the fixation and analyzed for the contents of unfixed hexavalent chromium, total Cr, Cu and As. Fixation curves are similar for red pine and aspen. Chromium fixation is extremely fast in red maple, while significant amounts of unfixed arsenic were present at the time of complete reduction of chromium. In all investigated species, the rate of As fixation increases with the strength of the treating solution, while the rate of Cu fixation decreases. Results of two sequential extraction sequences applied on CCA-C treated wood sawdust, with a range of inorganic and organic solvents, applied in order to dissolve / release one fixation product at the time, are presented. The total content of removed components was analyzed by ICP- AES and content of hexavalent chromium by diphenylcarbazide coloririmetric method. The results of sequential extractions indicate that selective removal of CCA fixation products can be achieved, and this approach may be applied for the investigation of fixation mechanisms. Further research is needed to better understand the particular influence of each of the investigated variables on the course of fixation.

Download document (372 kb)
free for the members of IRG. Available if purchased.

Purchase this document