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A discussion of current theories concerning CCA fixation
1983 - IRG/WP 3238
The understanding of the fixation mechanism of CCA and related preservatives in wood has been greatly improved by a significant series of recent scientific papers. In view of recent concerns in New Zealand regarding the long-term efficacy of CCA in high decay-hazard situations, it was considered appropriate to review this recent work and to contrast it with theories presented by previous workers.
D V Plackett


Non-stochiometric oxidation and ROS generation promoted by guaiacol lignin structures and lignocelluose surfaces may be a component of brown rot fungal degradation mechanisms
2019 - IRG/WP 19-10937
Model guaiacol compounds representing lignin monomers, as well as DHP-lignin and wood flour of controlled particle size were used to assess iron reduction at the pH of the natural wood cell wall. All compounds functioned as electron donors for ferric iron, with the lignin monomers demonstrating capacity for non-stochiometric reduction of iron with multiple moles of ferric ion reduced per mole of lignin monomer. Iron reduction was enhanced as pH decreased. The results provide a mechanism to explain how lignin may participate as part of a “moving radical front” after initial fragmentation of the lignocellulose cell wall by brown rot fungi. Further, relative to enzymatic action on wood, the data suggest a mechanism to generate electrons that would promote action by fungal enzymes that require an electron donor. The data also demonstrate how hydroxyl radicals would be generated to promote the generation of low levels of formaldehyde from lignin under conditions when lignin surfaces were exposed.
Y Tamarua, M Yoshidaa, L D Eltisb, B Goodell