Removal of Detrimental Dissolved and Colloidal Substance by a Combined Fungal and Enzyme Treatment System, 2000 Environmental Conference Proceedings

- X. Zhang, D. W. Stebbing, J. J. Soong, J. N. Saddler, R. P. Beatson, B. G. Chalmers, J. Ling -- Our previous work has shown that the white-rot fungus Trametes versicolor was capable of growing on mill process waters without added nutrients. In this study, a "typical" mill white water was used as media for the growth of Trametes versicolor. As the fungus grew on the process waters, it degraded many of the dissolved and colloidal organic compounds that caused problems with papermachine runnability and paper quality. More importantly, a large spectrum of enzymes, including hemicellulases, hydrolases and oxidative enzymes, was produced. The enzymes were collected as fungus culture filtrates after thress days of fungal growth and used to treat the above three types of white water. The treatment resulted in a considerable decrease in extractive and carbohydrate content as well as polymerization of low molecule weight phenolics into higher molecule weight lignin type of materials. The enzymes in the fungal culture filtrate were capable of surviving for extended times at temperatures of around 65 degrees C. This fungal enzyme treatment system may provide a means of mitigating problems with the build-up of detrimental organics during mill water system closure.