食品废水中典型偶氮类色素和致病菌的光催化去除研究

Seeking efficient, green and safe environment purification technology and material which can effectively remove azo pigments and pathogenic bacteria in food-processing wastewater is of great significance for protecting the ecological environment and human health. In this project, we intend to adopt the photocatalytic technology, and develop multifunctional graphene oxide (GO)/nanoporous g-C3N4 composite with excellent activity of adsorption-enrichment, photocatalytic degradation and disinfection. The photocatalytic space and electronic structure of g-C3N4 could be optimized via pore morphology controlling. The photo-generated charge migration and visible light absorption spectra of g-C3N4 could be promoted by compounding with GO. We also intend to study the structure-property relationship and synergistic effect mechanism of GO/nanoporous g-C3N4 composite photocatalyst, and reveal the product distribution, transformation pathways and degradation mechanism of azo pigments and pathogenic bacteria. GO-nanoporous g-C3N4 binary photocatalyst system not only can synchronously achieve the adsorption-enrichment and complete mineralization of azo pigments, but also can degrade the endotoxin while killing pathogenic bacteria, has incomparable advantages over other wastewater treatment technologies and materials. This project aims to develop the design strategy of efficient multifunctional photocatalytic material, extend the application prospect of photocatalytic technology in the field of environmental purification, and provide the research method and reliable basis for food wastewater treatment.

寻求高效、绿色、安全的环境净化技术和材料，实现对食品废水中高污染性和毒害性的偶氮类色素和致病菌的有效去除，对于保护生态环境和人类健康具有重要的意义。本项目拟采用光催化技术，通过多孔形貌调控优化g-C3N4进行光催化作用的空间和电子结构，与氧化石墨烯（GO）复合实现g-C3N4光生电荷的快速转移以及光谱吸收范围的拓展，开发出高活性的吸附富集-降解矿化-抗菌多功能GO/多孔g-C3N4复合可见光光催化材料，并探究材料的构效关系和协同作用机制，揭示偶氮类色素和致病菌的产物分布、转化途径和降解机理。GO-多孔g-C3N4二元协同光催化体系不仅能够同步实现对偶氮类色素的吸附富集和彻底矿化过程，还可以在杀灭致病菌的同时降解其内毒素，具有其他废水处理技术和材料无法比拟的优势。本项目旨在拓展高活性多功能光催化材料的研究思路以及光催化技术在环境净化领域的应用前景，并为高效处理食品废水提供研究方法和可靠依据。

寻求高效、绿色、安全的环境净化技术和功能化材料，实现对食品废水中高污染性和毒害性的偶氮类色素和致病菌的有效去除，对于保护生态环境和人类健康具有重要的意义。本项目采用光催化氧化技术，通过水热法、热刻蚀法以及分子自组装法调控g-C3N4的形貌，制备出多孔g-C3N4纳米片和多孔管状g-C3N4光催化剂，优化了g-C3N4进行光催化作用的空间和电子结构；通过自组装法和交联法将g-C3N4与氧化石墨烯纳米片(GO)/氧化石墨烯量子点(ox-GQDs)复合，制备出氧化石墨烯量子点/多孔g-C3N4 (ox-GQDs/PCNO)、g-C3N4纳米片/氧化石墨烯气凝胶以及氧化石墨烯量子点/多孔g-C3N4/氧化石墨烯(PCNGD-GOA)三元气凝胶复合光催化剂，实现了g-C3N4光生电荷的快速转移、光谱吸收范围的拓展以及吸附和回收利用能力的提高，成功开发出具有吸附富集-降解矿化-抗菌多重性能的GO/多孔g-C3N4复合光催化材料，实现对偶氮类色素和致病菌的有效去除。在可见光下，ox-GQDs/PCNO在4小时内对苋菜红的降解率为96.7%，降解速率约是多孔g-C3N4的3.1倍，在4小时内能够杀灭约99.6%的大肠杆菌，远高于PCNO的抗菌活性；而性能最佳的PCNGD-GOA在50分钟内对苋菜红的降解率为99.3%，降解速率约是ox-GQDs/PCNO的29.6倍，在80分钟内能够杀灭约99.8%的大肠杆菌，远高于ox-GQDs/PCNO的抗菌活性。GO/多孔g-C3N4复合材料对苋菜红的降解主要是通过打断偶氮基团、破坏萘环骨架以及去除-SO3-等过程形成脂肪酸等中间产物，再将其彻底矿化为CO2和H2O来完成的；GO/多孔g-C3N4复合材料杀灭大肠杆菌主要是先与其进行紧密接触，再通过光催化作用产生的大量活性物种攻击大肠杆菌的细胞膜，使其发生细胞畸变、细胞壁破损，导致细胞内容物漏出，最终致使大肠杆菌细胞失活。本项目拓展了高活性多功能光催化材料在环境净化领域的应用前景，并为高效处理食品废水提供研究方法和可靠依据，对于建立高活性多功能光催化材料的设计和研究方法具有一定的指导意义。