纸浆二氧化氯漂白过程木素-二氧化氯复合体的形成及转化机制

可吸附有机卤素（AOX）是纸浆漂白过程中产生的最主要的一种持久性有机污染物（POPs），具有持久性/长期残留性、生物蓄积性、高毒性等。目前人们对AOX的生成机理认知仍然有限，现有的AOX减量技术对AOX的减量效果缺乏高效性和稳定性，未能从根本上解决AOX减量的科学难题。因此，深度解析AOX生成的反应历程、认识漂白过程中间产物的形成及转化为自由基的机制，为构建从源头减少漂白过程AOX生成的技术体系奠定基础，这也是纸浆漂白过程AOX的生成和减量领域有待深入研究的科学问题。本项目拟对未漂桉木浆进行木素的提取及表征，系统研究提取木素、与提取木素具有相应官能团的木素单体模型物和木素二聚体模型物与二氧化氯反应过程木素-二氧化氯复合体的形成规律，探索木素-二氧化氯复合体转化为自由基的机制，进一步阐明木素与二氧化氯反应生成AOX的机理，为从源头减少纸浆漂白过程AOX的生成提供理论依据。

Adsorbable organic chlorine (AOX) is the most important persistent organic pollutant (POPs) produced in pulp bleaching, which has persistent, long-term residue, bioaccumulation and high toxicity. However, people's cognition on the formation mechanism of AOX is still limited. The existing AOX reduction technology lacks efficiency and stability in the reduction effect of AOX. The scientific problem of AOX reduction cannot be solved fundamentally. Therefore, the reaction process of AOX formation, the understanding of the formation and transformation mechanism of intermediate products (transition state) are deeply analyzed in bleaching process. It helps to set a foundation for the technical system of reducing AOX generation in bleaching process from the source, which is also a scientific problem to be further studied in the field of AOX generation and reduction in pulp bleaching process. This project intends to extract and characterize the lignin from unbleached pulp, and choose the lignin monomer model and lignin dimer model with corresponding functional groups. The formation of Lignin - chlorine dioxide complex in the reaction process of extracting lignin, lignin monomer model and lignin dimer model with chlorine dioxide has been systematically studied. To explore the mechanism of conversion of lignin chlorine dioxide complex into free radicals, and further clarify the mechanism of AOX generated by the reaction of lignin and chlorine dioxide. It provides theoretical support for reducing the generation of AOX in bleaching process from the source.