Use of xylanases to decrease the formation of AOX in kraft pulp bleaching

Xylanase pretreatment of softwood and hardwood kraft pulps permitted high-brightness bleaching to be achieved using substantially reduce chlorine charges. These reductions were translated to the bleach effluents as reductions in AOX and general improvements in the effluent character. Following xylanase pretreatment, hardwood pulp had reduced organic halide content in comparison to the controls.