WOOD EXTRACTIVES AND PITCH PROBLEMS - ANALYSIS AND PARTIAL REMOVAL BYBIOLOGICAL TREATMENT

Regardless of pulping and bleaching procedures. wood extractives prese nt in both softwoods and hardwoods cause significant technical and eco nomic pitch problems in the pulp and paper industry. When they are rel eased in pulp mill effluents they also have a detrimental impact on th e environment. Wood extractives are mainly composed of triglycerides, fatty acids, resin acids, steryl esters, sterols, and other non-saponi fiables. A solid-phase extraction method was used to rapidly separate the nonvolatile lipid fraction of wood extractives into five major cla sses. Using this method, the extractives in the sapwood and heartwood oi trembling aspen and lodgepole pine were analysed. The possibility o f decreasing wood extractives with fungal treatments was also tested. Four promising fungal strains were selected, their ability to remove w ood extractives was investigated and compared with the commercial prod uct Cartapip(TM)97. Ali the strains hydrolysed the wood triglycerides and removed some of the steryl esters and waxes.