The Effect of Fungicide Distribution in Wood on the Rate of Diffusion in and from Wood

Pentachlorophenol is one of the oldest chemicals used for protecting wood against fungi. A drawback for this chemical is its potential release in water when the treated wood is in contact with water. A method of impregnation of wood is described, leading to a low amount of PCP in the wood, and with a non uniform concentration throughout the wood and high concentration on the wood surface. The release of PCP in water from wood samples treated in this new way is studied. When these treated samples are in contact with water, two PCP transports are observed: the one with the usual release in the external water, the other with the diffusion inside the wood from the usual surface. In spite of the low amount of PCP in the wood, protection against fungi may be effective, as the release of PCP is thus low. Modelling and experiments are used for treating the problem.