School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control (SKLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control , Tsinghua University , Beijing 100084 , China.
Department of Chemical, Biochemical, and Environmental Engineering , University of Maryland Baltimore County , 1000 Hilltop Circle, Engineering 314 , Baltimore , Maryland 21250 , United States.
Environ Sci Technol. 2019 Feb 5;53(3):1564-1575. doi: 10.1021/acs.est.8b05827. Epub 2019 Jan 11.
This study describes a promising sunlight-driven photocatalyst for the treatment of ofloxacin and other fluoroquinolone antibiotics in water and wastewater. Perylene diimide (PDI) supramolecular nanofibers, which absorb a broad spectrum of sunlight, were prepared via a facile acidification polymerization protocol. Under natural sunlight, the PDI photocatalysts achieved rapid treatment of fluoroquinolone antibiotics, including ciprofloxacin, enrofloxacin, norfloxacin, and ofloxacin. The fastest degradation was observed for ofloxacin, which had a half-life of 2.08 min for the investigated conditions. Various light sources emitting in the UV-vis spectrum were tested, and blue light was found to exhibit the fastest ofloxacin transformation kinetics due to the strong absorption by the PDI catalyst. Reactive species, namely, h, O, and O, comprised the primary photocatalytic mechanisms for ofloxacin degradation. Frontier electron density calculations and mass spectrometry were used to verify the major degradation pathways of ofloxacin by the PDI-sunlight photocatalytic system and identify the transformation products of ofloxacin, respectively. Degradation mainly occurred through demethylation at the piperazine ring, ketone formation at the morpholine moiety, and aldehyde reaction at the piperazinyl group. An overall mechanism was proposed for ofloxacin degradation in the PDI-sunlight photocatalytic system, and the effects of water quality constituents were examined to determine performance in real water/wastewater systems. Ultimately, the aggregate results from this study highlight the suitability of the PDI-sunlight photocatalytic system to treat antibiotics in real water and wastewater systems.
本研究描述了一种有前途的阳光驱动光催化剂，用于处理水中和废水中的氧氟沙星和其他氟喹诺酮类抗生素。通过简单的酸化聚合方案制备了吸收宽光谱阳光的苝二酰亚胺（PDI）超分子纳米纤维。在自然光下，PDI 光催化剂实现了氟喹诺酮类抗生素的快速处理，包括环丙沙星、恩诺沙星、诺氟沙星和氧氟沙星。观察到氧氟沙星的最快降解，在研究条件下其半衰期为 2.08 分钟。测试了各种在 UV-vis 光谱中发射光的光源，发现蓝光由于 PDI 催化剂的强吸收，表现出最快的氧氟沙星转化动力学。h、O 和 O 等活性物质构成了氧氟沙星降解的主要光催化机制。前沿电子密度计算和质谱分别用于验证 PDI-阳光光催化系统对氧氟沙星的主要降解途径，并确定氧氟沙星的转化产物。降解主要通过哌嗪环的脱甲基、吗啉部分的酮形成以及哌嗪基的醛反应发生。提出了 PDI-阳光光催化系统中氧氟沙星降解的总体机制，并考察了水质成分的影响，以确定在实际水/废水中的处理性能。最终，本研究的综合结果强调了 PDI-阳光光催化系统在实际水和废水中处理抗生素的适宜性。
