基于构效关联的可见光催化与生物降解直接耦合体系靶向构建及其耦合机制研究

Research results showed that Trichlorophenol (TCP) could be effectively degraded by the intimate coupling of UV photocatalysis by TiO2 and biodegradation (ICPB), which has been considered as a promising wastewater treatment technology. However, this newly developed UV-driven process leads to the biofilm detachment and increase of SMP. Our previous study indicates that the above problem could be solved by the visible-light-photocatalysis induced ICPB. But, few work has been done on the optimization of visible-light induced ICPB system and its coupling mechanism, resulting in limited development in ICPB technology. In this study, the relevance among facet structure, reactive oxygen species (ROS) and photocatalytic performance will be deeply investigated. A visible-light-responsive photocatalyst–biofilm composite with high performance will be prepared, which couples photocatalysis and biodegradation intimately. The mutual effect of photocatalysis and biodegradation on each other will be explored and also as the mechanism of intimate coupling of visible light responsive photocatalysis and biodegradation. A modeling of including photocatalytic TCP degradation - microorganism inhabitation - microorganism growth will be set up. An internal circulating fluidized bed will be used as the reactor and the controlling strategy will be studied for better use of the prepared composite. This research could help to break the present limitations and to the deeply understand the behavior and the mechanism of the intimate coupling of visible light responsive photocatalysis by TiO2 and biodegradation, which could lay a systemic foundation for its efficient application and provide a reliable method for the treatment of refractory organic wastewater with high efficient and low cost.

光催化与生物降解直接耦合（ICPB）可有效降解TCP。然而，目前ICPB的研究仅采用UV作为光催化驱动，存在生物膜大量脱落与SMP溶出等严重问题。课题组前期工作证明，可见光催化诱导的ICPB能够有效解决上述问题。但关于可见光下ICPB材料体系优化与耦合机制工作尚未开展，限制了ICPB技术应用。项目依据晶面结构、活性氧（ROS）物种、催化效能之间的关联，基于改性TiO2开发可见光催化剂，构建可见光催化-生物降解直接耦合体系，深入研究光催化与生物降解的相互作用机制，探求TCP降解途径与机制，建立综合光催化-TCP转化、生物抑制及微生物生长的数学模型，优化ICPB体系及运行调控策略，充分发挥ICPB对TCP矿化优势。本研究突破当前研究局限，深入解析ICPB行为与机制，为高效可见光催化与生物降解直接耦合技术奠定系统的理论基础，为难降解有机废水经济、高效处理提供可靠的新方法。

光催化-生物降解直接耦合技术（ICPB）能够解决单一光催化氧化矿化有机物不完全和生物降解难氧化持久性有机物的局限。然而，针对ICPB的耦合机制仍旧解析不清。项目采用元素掺杂、晶面调控和异质结搭建等手段，制备了多种形貌结构可见光响应催化剂。通过辨识适宜活性物种遴选了催化剂，并获得了低温条件下催化剂稳定负载的方法。在此基础上，研发了基于可见光响应的ICPB技术体系。该体系对污染物的矿化效率大幅提高，并解决了紫外光ICPB下SMP 溶出、难降解中间产物大量累计的问题。利用数学模型深入解析了ICPB体系中光催化与生物降解相互作用机制。引入基质共代谢手段，进一步提高了高浓度抗生素废水的矿化效率，大幅降低了产物毒性，突破了ICPB对高毒性污染物降解的局限。