磁性分子印迹材料去除水中氟喹诺酮类抗生素的效能与选择吸附-催化降解耦合机制研究

Fluoroquinolones are one kinds of antibiotics, which have been detected frequently in urban water environment. Comparing with the limited removal efficiency of conventional treatment processes, heterogeneous photocatalytic oxidation is a more effective control technology for fluoroquinolones. However, catalyst couldn’t effectively remove the micro organic pollutants such as fluoroquinolones in aquatic environment with multiple interactive pollutants because of its non-selectivity. Based on the research of the direct photolysis and photocatalytic degradation characteristics of the fluoroquinolone compounds, photocatalyst modified by surface molecular imprinting technique with magnetic materials and metal elements is applied to investigate the selective adsorption performance and photocatalytic degradation of target pollutants in heterogeneous system. A combined experiment about the selective adsorption, photocatalytic mechanism and interfacial reaction of fluoroquinolones removed by magnetic photocatalyst modified with molecular imprinted film is carried out, to illuminate the coupling mechanism of adsorption and photochemical reaction. This study also declares the influence of aquatic multi-factors and reaction conditions caused to the removal of fluoroquinolones by magnetic photocatalyst modified with molecular imprinted film. All above will provide the theoretical guidance for the control technology of fluoroquinolones in water and the application of photocatalytic technology combined with surface molecular imprinting and magnetic separation in water pollution control.

氟喹诺酮类物质是城市水环境中检出率较高的一类抗生素污染物，常规处理工艺对其去除效果有限，非均相光催化氧化是一种有效的控制技术，但是催化剂无选择性、易受介质影响的问题使其难以在多种污染物共存的复杂水体中优先去除低浓度目标物质。本项目基于氟喹诺酮类物质直接光解和光催化降解的反应特性，采用表面分子印迹技术和磁性基团对光催化剂进行改性修饰，考察非均相体系中磁性分子印迹催化剂对目标污染物的选择吸附性能和光催化降解效能，将特异吸附机理、光催化去除机制与界面反应行为结合研究，揭示磁性分子印迹催化材料的吸附-光解耦合作用机制，阐明实际水体中介质因子和反应条件对磁性分子印迹催化作用的影响规律，为水中氟喹诺酮类污染物的去除以及分子印迹、磁分离结合光催化技术在微污染有机物控制领域的应用提供理论支持和技术指导。

近年来抗生素物质因其在水环境中不断检出、对生态系统有潜在风险而备受关注，探索水中抗生素污染物的高效去除技术具有现实意义。本项目采用表面分子印迹技术结合磁分离技术制备了具有选择性吸附与光催化再生特性的磁性分子印迹催化材料（MMIP），考察了材料对氟喹诺酮类抗生素的去除效能和作用机理。磁性分子印迹材料对诺氟沙星的吸附过程符合拟二级反应动力学和Langmuir等温线模型，对氟喹诺酮类物质具有选择性吸附能力，吸附效率与目标污染物的分子结构、官能团和极性密切相关。光催化反应60分钟内MMIP材料可完全降解诺氟沙星，反应150分钟后矿化率基本稳定，降解机制以取代反应、消除反应为主。水环境介质因素对MMIP材料去除氟喹诺酮类物质的吸附和光催化过程均有影响，关键控制因素是pH值、腐殖酸和铁离子。研究表明磁性分子印迹催化材料能够同时实现氟喹诺酮类物质的有效降解和材料的原位再生，具有良好的可重复利用性。本项目为水中抗生素污染物的控制去除以及高级氧化工艺的应用提供了数据支撑和技术指导。