Degradation of residual lignin in pulp and environmental pollutants by MnP-lipid

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In this study, manganese peroxidase (MnP) reaction in the presence of unsaturated fatty acid (UFA), so called MnP-lipid peroxidation system, was investigated for the degradation of the residual lignin in unbleached kraft pulp and the degradation of environmental pollutants.1. The pulp brightness increase was increase by the addition of UFA to MnP-bleaching system. The proxidation value in the reaction mixture was well collated to the increase of pulp brightness. However, lipid peroxidation derived by lipoxidase treatment did not increase pulp brightness. These results suggest that Mn (III) produced by MnP action and lipid peroxidation synergistically degrade lignin. Additionally, lignin in the pulp also accelerated the lipid peroxidation in MnP-lipid peroxidation system.2. Degradation of polyaromatic hydrocarbons (PAH) by MnP-lipid peroxidation system was investigated. Anthracene (AT) and benzopyrene were effectively degraded by MnP-lipid peroxidation system. A kinetic study indicates that peroxidation of UFA was much faster than PAH degradation. It is also suggested that lipid peroxidation reaction involves two reaction, formation of lipid-peroxide intermediates and generation of free radicals, and the former reaction is faster. Degradation of PAH was not changed in the MnP-lipid peroxidation system using different UFA, suggesting that wide range of UFA are functional for this system.3. Removal of estrogenic activity of bisphenol A (BPA) and nonylphenol (NP) by MnP-lipid peroxidation system was attempted. The estrogenic activity of BPA and NP was completely removed within a 6 to 12 hour treatment. The extended treatment to 48 h never regenerates the estrogenic activity.