Enzymatic delignification optimization of wheat straw soda-AQ pulp by laccase-mediator treatment

摘要

The bleaching of wheat-straw pulps have a great impact on the environment since Chlorine and Chlorite compounds are widely used. Extent delignification has been become very common way to decrease the application amount of bleaching chemicals relating to decrement of polluting load from bleaching operation. Laccase has been proven that it has a higher selectivity to degrade lignin in pulp. In this paper, the effects on delignification of wheat-straw pulp by laccase at various conditions such as temperature, pulp consistency, oxygen pressure and pH were investigated. The major factors were optimized resulting as, 10 % of pulp consistency, 0.4MPa of oxygen pressure, pH 4.4, 45°C of temperature, 30u/g as laccase dosage, 3 % of HBT as well as 4 hours for reaction time. At the optimal condition, the laccase treatment provides treated pulps with degree of delignification about 71 % and brightness gain of 18.4 units.