生物炭光催化产生活性氧自由基及其降解邻苯二甲酸类污染物的微观机制研究

Since biochar has been reported as the potential carbon storage to reduce CO2 emission to atmosphere, the land application of biochar is increasingly being considered for potential agronomic and environmental benefits, e.g., enhancing carbon sequestration, nutrient retention, and crop productivity; and increasing the pH of acidic soil and reducing bioavailability of environmental contaminants. However, the knowledge about the transformation of organic pollutant with biochar is rather limited. The photochemical behavior of biochar and its effect on the photodegradation of organic contaminants were rarely investigated. In this study, the degradation of PAEs, a type of emerging organic contaminants, with biochar as photocatalyst was examined in aqueous solutions. To elucidate the mechanism of PAEs degradation and reactive oxygen species (ROS) formation in biochar photocatalytic system, the types and concentrations of ROS, as well as their contributions for PAEs degradation were quantified. Furthermore, the contribution of biochar components such as carbon matrix and dissolve organic matter (DOM) to ROS formation and PAEs degradation was also studied. The effects of environmental factors such as pH, dissolved oxygen, anion/cation and DOM on ROS formation and PAEs degradation were investigated in the environmentally relevant water. Finally, the biochar photocatalytic system would be used for the degradation of PAEs in the wastewater. This program would provide useful information for understanding the effects of biochar on the transformation of organic contaminants in the natural aquatic environment, and develop a new metal-free photocatalyst for the purification of wastewater.

自从生物炭的固碳作用被认识到以后，其越来越引起各国科学家的关注，被广泛地应用于调节土壤酸碱度、保持土壤肥力和提高作物产量、固定重金属和吸附有机污染物等。但目前有关生物炭对有机污染物转化降解的研究较少，生物炭的光化学行为及其对环境中有机污染物光催化降解的影响更是不得而知。本项目将围绕生物炭和新型有机污染物邻苯二甲酸酯（PAEs），系统地开展生物炭光催化产生活性氧自由基（ROS）及其降解PAEs的机制研究，建立生物炭光催化体系ROS的定性和定量表征方法；探明生物炭光催化产生ROS的控制因子及其机制过程；定量表征生物炭光催化体系中碳骨架、溶解性有机质（DOM）对ROS产生和PAEs降解的贡献；研究生物炭对环境水体中PAEs光降解的影响，并考察环境因子对ROS产生和PAEs降解的影响，尝试利用生物炭光催化降解废水中PAEs。本项目的顺利实施将为生物炭的研究提供一个新的方向。

自从生物炭的固碳作用被认识到以后，其越来越引起各国科学家的关注，被广泛地应.用于调节土壤酸碱度、保持土壤肥力和提高作物产量、固定重金属和吸附有机污染物等。.但目前有关生物炭对有机污染物转化降解的研究较少，生物炭的光化学行为及其对环境中有机污染物光催化降解的影响更是不得而知。本项目围绕着生物炭和新型有机污染物邻苯二甲酸酯（PAEs），系统地开展生物炭光催化产生活性氧自由基（ROS）及其降解PAEs的机制研究。揭示了生物炭光催化降解邻苯二甲酸酯类污染物的效能与机制；建立了基于电子顺磁共振和分子探针技术的生物炭光催化体系自由基的定性和定量表征方法；阐明了生物炭光催化体系不同类型自由基降解邻苯二甲酸酯类污染物的贡献；探明了实际环境水体中生物炭颗粒光转化邻苯二甲酸二乙酯的机理。项目资助下，共发表SCI论文21篇，重文核心期刊1篇，申请发明专利2项。以上成果将为揭示生物炭影响水体中有机污染物的光降解过程提供了理论依据，为发展基于生物炭光催化处理废水中有机污染物的技术提供了支撑。