制浆造纸企业采用无元素氯（ECF）技术漂白纸浆可以实现环境、经济和社会效益的统一。二氧化氯是ECF漂白技术的主要漂剂，具有良好的脱木素选择性，但漂白过程生成的少量可吸附有机卤素（AOX）具有较强的毒性和难降解性。目前，国内外学者普遍认为AOX主要来源于木素，并对二氧化氯与木素反应生成AOX的机理进行了研究，而半纤维素和己烯糖醛酸(HexA)对AOX生成的影响机制研究未见报道。本项目拟研究半纤维素和HexA对AOX生成的影响规律，构建半纤维素、HexA与二氧化氯反应生成AOX的动力学模型，推导半纤维素、HexA和二氧化氯反应的中间状态及可能发生的基元反应，并利用分子模拟技术对反应物和二氧化氯反应生成AOX的过渡态进行计算，确定半纤维素、HexA与二氧化氯反应时发生断裂的化学键及二氧化氯进攻半纤维素分子和HexA分子的位置，推测AOX生成的反应路径，为从源头减少AOX的生成提供理论依据。

The benefits of environmental, economic and social can achieve integrate when elemental chlorine free (ECF) process is employed in bleaching of pulp. As the main reagent of ECF bleaching technology, chlorine dioxide have a good selectivity delignification, but the absorbable organic halogens (AOX) discharging in the bleaching has strong toxicity and degradation-resistant. At present, researchers generally agree that AOX mainly comes from the residue lignin of the pulp, and the reaction of chlorine dioxide with lignin were studied. But influence of hemicellulose and hexeneuronic acid (HexA) on AOX formation mechanism have not been reported. This project focus on the influence of hemicellulose and HexA on AOX formation, kinetic model of AOX formation will be established during hemicellulose and HexA reacting with chlorine dioxide. The reaction intermediates will be analyzed and AOX formation transient state will be calculated by molecular simulation technology. Breaking of chemical bonds will be determined during hemicellulose and HexA reacting with chlorine dioxide. The reaction path will be speculated, which will provide a theoretical basis for reducing the formation of AOX.