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，但漂白过程生成的少量可吸附有机卤素（AOX）具有较强毒性和持久性。目前，国内外学者普遍利用单一木素模型物来研究木素与二氧化氯反应生成AOX的机理，而木素不同结构单元及结构单元间的连接方式对木素与二氧化氯反应生成AOX的影响机制研究未见报道。本项目拟对未漂桉木浆进行木素提取及表征，选取与提取木素具有相应官能团的木素单体模型物并合成以不同连接键连接的木素二聚体模型物，系统研究提取木素、木素单体模型物以及木素二聚体模型物与二氧化氯反应生成AOX的反应机制，并利用分子模拟技术对木素二聚体模型物与二氧化氯反应生成AOX的过渡态进行计算，确定木素二聚体模型物化学键断裂的方式和位置，推测木素与二氧化氯反应生成AOX的路径，为从源头控制AOX的生成提供理论依据。

The unification of environmental, economic and social benefits was achieved using the element-free chlorine (ECF) bleaching technology in pulp and paper mill. Chlorine dioxide is the main bleaching agent in ECF bleaching. However, a small amount of adsorbed organic halogen (AOX) formation in bleaching process has strong toxicity and durability. At present, AOX formation mechanism of lignin reacts with chlorine dioxide has been studied by using a single lignin model. The effect of different lignin structural units and connections on AOX formation has not been reported. In this project, the unbleached eucalyptus wood pulp was used as raw material. The lignin extraction and characterization were researched. The lignin model compound which the same functional group with the extracted lignin was selected, then its dimer was synthesized with different bonds. The reaction mechanism of lignin, lignin model compound, its dimer and chlorine dioxide was studied. The reaction intermediates will be analyzed and AOX formation transient state will be calculated by molecular simulation technology. The pathway to AOX formation by lignin and chlorine dioxide was speculated, which will provide a theoretical basis for reducing the formation of AOX.