Summary
A titration procedure was used to confirm carbon dioxide evolution from wood treated with solutions containing chromic acid and to quantify the effects of species (red pine vs soft maple), solution concentration and reaction temperature on the rate and amount of CO2 evolved. Small blocks or chips were vacuum treated with either chromated copper arsenate (CCA) wood preservative or chromic acid solutions and the release of CO2 monitored until the reaction was complete. Significant volumes of CO2 were measured. This is attributed to the oxidation and subsequent decarboxylation of primary hydroxyl groups on wood constituents. The ratio of moles of CO2 produced to moles of chromium added to the wood ranged from about 0.07 to 0.24 depending on the wood species, solution properties and fixation conditions. This accounted for from 9 to 32% of the total oxidation potential of the hexavalent chromium applied. The relative amounts of CO2 produced were higher for maple than for red pine. The rate of CO2 evolution was also higher in the maple samples, consistent with the higher rate of chromium reduction in soft maple compared to red pine. The amount of C02 produced was approximately proportional to the amount of hexavalent chromium in the CCA treating solution although the ratio of CO2 produced to chromium added to the wood increased slightly with increasing solution concentration. The relative amounts of CO2 produced increased with increasing fixation temperature over the 50–90 °C range in both species. The rate of CO2 evolution was accelerated as the fixation temperature was increased. The rates and amounts of CO2 produced were similar for CCA and Cr03 treatments containing the same concentration of chromic acid. Copper and arsenic components of the CCA solution did not appear to have any effect on the decarboxylation reaction.
Similar content being viewed by others
References
CCME (1993) Guidance manual on sampling, analysis, and data management for contaminated sites. II. Analytical methods summaries. Canadian Council of Ministers of the Environment. Report CCME EPC-NCS66E
Cooper PA, Ung YT (1989) Moderate temperature fixation of CCA in red pine poles. Int. Res. Group on Wood Preserv. Doc. IRG/WP/3504/3525
Kaldas M, Cooper PA (1993) Oxidation of wood components during CCA-C fixation. Int. Res. Group on Wood Preserv. Doc. IRG/WP 93-30024
Levenkova SI, Klimavich SN (1978) Determination of CO2 in urea. Metody Anal. Kontrolya Kach. Prod. Khim. Prom. (7): 29–30
McNamara WS (1989) CCA fixation experiments. Int. Res. Group on Wood Preserv. Doc. IRG/WP/3504/3505
Ostmeyer JG, Elder TJ, Littrell TM, Tatarchuk BJ (1988) Spectroscopic analysis of southern pine treated with chromated copper arsenate. I. X-ray photoelectron spectroscopy (XPS). J. Wood Chem. Technol. 8(3): 413–439
Ostmeyer JG, Elder TJ, Winandy JE (1989) Spectroscopic analysis of southern pine treated with chromated copper arsenate. II. Diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). J. Wood Chem. Technol. 9: 105–122
Ruddick JNR, Yamamoto K, Wong PC, Mitchell KAR (1992) X-ray photoelectron spectroscopic analysis of CCA treated wood. Int. Res. Group on Wood Preserv. Doc. IRG/WP/3700-92
Williams RS, Feist WC (1984) Application of ESCA to evaluate wood and cellulose surfaces modified by aqueous chromium trioxide treatment. Colloids and Surfaces. 9(3):253–271
Yamamoto K, JNR Ruddick PC, Wong, KAR Mitchell (1991). X-ray photoelectron spectroscopic analysis of CCA treated wood. Proc. Can. Wood Preserv. Assoc. 12: 238–251
Author information
Authors and Affiliations
Additional information
We gratefully acknowledge the financial support of the Natural Sciences and Engineering Research Council of Canada, Natural Resources Canada;, LPB Poles Inc., Masson Quebec, Timber Specialties Ltd., Campbellville Ontario and Guelph Utility Pole Co. Ltd., Guelph Ont. for this study.
Rights and permissions
About this article
Cite this article
Porandowski, J., Cooper, P.A., Kaldas, M. et al. Evolution of C02 during the fixation of chromium containing wood preservatives on wood. Wood Sci.Technol. 32, 15–24 (1998). https://doi.org/10.1007/BF00702556
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00702556