Moldes D, Vidal T
Department of Textile and Paper Engineering, Universitat Politècnica de Catalunya, Colom 11, E-08222 Terrassa, Spain.
Bioresour Technol. 2008 Dec;99(18):8565-70. doi: 10.1016/j.biortech.2008.04.008. Epub 2008 May 21.
Different operating conditions (viz. pulp consistency, oxygen pressure and treatment time) in the biobleaching of eucalyptus kraft pulp with the laccase-HBT system was tested in order to describe their effect and normalize a biobleaching protocol. A high O(2) pressure (0.6MPa) was found to result in improved laccase-assisted delignification of the pulp. Also, a high pulp consistency (10%) and a short treatment time (2h) proved the best choices with a view to obtaining good pulp properties (kappa number and ISO brightness) under essentially mild conditions. The laccase-HBT treatment was found to result in slight delignification (in the form of a 20-27% decrease in kappa number); however, an alkaline extraction stage raised delignification to 41-45%, a much higher level than those obtained in the control tests (16-23%). Also, the use of hydrogen peroxide in the extraction stage resulted in improved brightness (14-19%), but in scarcely improved delignification (4-7%). Treating the pulp with the laccase-HBT system reduced the amount of hydrogen peroxide required for subsequent alkaline bleaching by a factor of 3-4 relative to control tests.
为了描述不同操作条件（即纸浆浓度、氧气压力和处理时间）在漆酶 - HBT 体系对桉木硫酸盐浆进行生物漂白中的作用并规范生物漂白方案，对这些条件进行了测试。发现高氧气压力（0.6MPa）可提高漆酶辅助的纸浆脱木素效果。此外，为了在基本温和的条件下获得良好的纸浆性能（卡伯值和 ISO 亮度），高纸浆浓度（10%）和短处理时间（2 小时）被证明是最佳选择。发现漆酶 - HBT 处理会导致轻微脱木素（卡伯值降低 20 - 27%）；然而，一个碱抽提阶段可将脱木素率提高到 41 - 45%，远高于对照试验（16 - 23%）所获得的水平。此外，在抽提阶段使用过氧化氢可提高亮度（14 - 19%），但脱木素几乎没有改善（4 - 7%）。与对照试验相比，用漆酶 - HBT 体系处理纸浆可使后续碱漂白所需过氧化氢量减少 3 - 4 倍。
