Micronized Copper Preservative Systems: Observations on the Release of Cupric ion (Cu2+) from Treated Wood and Performance against Wood Decay Fungi
J Zhang, R Ziobro
In an attempt to address the mechanism of action of micronized copper preservatives, a 20-week continuous water leaching study was conducted. The leaching results indicated that, once impregnated in wood, micronized copper preservatives continuously release cupric ion, and the levels of cupric ion released from micronized copper treated wood are higher than those released from CCA treated wood, and similar to those from ACQ-D treated wood with the exception of the first few leaching cycles. A 30-month soil bed fungal cellar test was also conducted, and the results revealed that micronized copper quat performed at least as well as ACQ-D against soft rot, confirming the presence of mobile cupric ion in the S2 layer of wood cell wall. In addition, two field stake studies of micronized copper preservatives were also conducted, and the results indicate that micronized preservative systems provide excellent long-term protection against wood destroying fungi and insects, and perform at least as well as ACQ-D.
Keywords: micronized copper, quaternary ammonium, tebuconazole, soft rot, brown rot, white rot, fungi, wood decay, termites, insects, wood pH, water solubility, copper solubility, cupric ion, mobile copper, leaching, leachability, leachate