硝基芳香族化合物的生物电化学还原竞争作用机制

Bioelectrochemical reduction technology integrates the advantages of biological technology and electrochemical technology. Insufficient of traditional anaerobic reduction process, such as low efficiency, high cosubstrate dosage and unstability could be avoided by the application of bioelectrochemical technology. However, in the process of bioelectrochemical reduction for nitroaromatic compounds (NACs), the reduction performance is significantly influenced by the structure of NACs, which depends on the position and the number of nitro groups, and the type of substituents.In addition, the reduction performance is also influenced by the oxidative substrates, such as nitrate and sulphate, which are commonly found in wastewaters containing NACs.In this project, the bioelectrochemical reduction performance of NACs with different structure will be analysed. Quantum chemistry method will be used to extract and select the molecular descriptors, which are closely relative with the reducive performance of NACs. The model of structure-activity relationship will be built through SVM operation. The inherent relationship between the structure of NACs and bioelectrochemical reduction performance will be ascertained. The competition mechanism among NACs with different structure, which coexist in the bioelectrochemical reduction process, will be clarified. The competition mechanism of oxidative substrates, which are commonly found in wastewater containing NACs, towards the reduction process of NACs, will be discussed. The key factors and control strateges for bioelectrochemical reduction of NACs under complex water quality conditions will be revealed. Technical basises for the engineering application of bioelectrochemistry in wastewater treatment will be provided through the exploration of the above key scientific problems.

生物电化学还原技术综合了生物技术和电化学技术的优势，可望解决传统厌氧还原工艺处理效率低、共代谢基质消耗量大、难以稳定运行等不足。然而在硝基芳香族化合物（NACs）的生物电化学还原过程中，NACs的结构（硝基位置和数量、取代基团类型）及NACs废水中常见的氧化态物质（硝酸根、硫酸根等）对NACs的还原性能具有显著影响。本项目拟对不同结构的NACs的生物电化学还原性能进行分析，采用量子化学计算方法提取并筛选与NACs还原性能相关的分子描述符，进行SVM运算建立构效关系模型，确定NACs结构与生物电化学还原性能之间的内在联系，阐明不同结构NACs共存时的的竞争还原作用机制；探讨NACs废水中常见的氧化态物质对NACs还原过程的竞争作用机制；揭示复杂水质条件下NACs生物电化学还原过程的关键影响因素及控制策略。通过上述关键科学问题的探索，可望为生物电化学技术的废水处理工程应用提供技术基础。

生物电化学还原技术综合了生物技术和电化学技术的优势，可望解决传统厌氧还原工艺处理效率低、共代谢基质消耗量大、难以稳定运行等不足。然而在硝基芳香族化合物（NACs）的生物电化学还原过程中，NACs的结构（硝基位置和数量、取代基团类型）及NACs废水中常见的氧化态物质（硝酸根、硫酸根等）对NACs的还原性能具有显著影响。本项目对不同结构的NACs的还原性能进行了分析，采用量子化学计算方法提取并筛选与NACs还原性能相关的分子描述符，阐述了NACs还原性能与结构之间的关系，探讨了NACs废水中常见的氧化态物质对NACs还原过程的竞争作用机制。结果表明，取代基团（羟基、氯基、甲醚基）的吸电子和供电子特性显著影响了NACs结构上氮原子的电子云分布，导致了NACs的还原性能的显著差异，引入给电子类的取代基会使得NPs的还原变得更难，而引入吸电子类取代基会使NPs的还原变得更容易；给电子类取代基的邻位硝基易于发生优先还原，而吸电子类取代基的对位硝基易于发生优先还原；分子内氢键的存在导致邻位取代的硝基更容易被还原；NACs结构上硝基的数量越多越容易被还原。硝酸根的存在对NACs的还原具有显著的负面影响，硫酸根的存在对NACs的还原具有一定的促进作用。通过上述关键科学问题的探索，可望为生物电化学技术的废水处理工程应用提供技术基础。