Method for reducing hexenuronic acid in bagasse pulp through biological enzyme pretreatment

The invention discloses a method for reducing hexenuronic acid in bagasse pulp through biological enzyme pretreatment. According to the method, composite biological enzyme is adopted to pretreat bagasse pulp before the bagasse pulp is bleached by using chlorine dioxide, and good compatibility of ligninases and hemicellulase is utilized to improve the diffusion of enzyme in pulp so as to hydrolyze connection of hexenuronic acid and hemicellulose as well as lignin, and achieve the purposes of improving the bleaching efficiency of bagasse pulp by using chlorine dioxide, reducing the use amount of chlorine dioxide and reducing the wastewater pollution burden. The content of hexenuronic acid in the bagasse pulp pretreated by using biological enzyme is reduced by 80-90%, the whiteness stability of the bagasse pulp which is bleached by using chlorine dioxide is relatively good, the use amount of chlorine dioxide can be reduced by 30-50% when identical whiteness is achieved, and the content of AOX in bleaching wastewater is reduced by 25-35%.