Dept. of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
Dept. of Chemical Engineering, School of Engineering, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
J Environ Manage. 2019 May 1;237:595-608. doi: 10.1016/j.jenvman.2019.02.089. Epub 2019 Mar 1.
The purpose of this research was the preparation and photocatalytic evaluation of a novel nanocomposite (NC) based on FeO/ZnO, to eliminate four persistent antibiotics in surface waters: sulfamethoxazole, trimethoprim, erythromycin and roxithromycin. Prior to the operation of the photocatalytic reactor, the influence of pH (3-9), catalyst concentration (50-800 mg L, oxidant dose (0-100 mg L) and concentration of different targets (10-100 μg L) on the catalytic efficiency was evaluated. The analysis of reaction kinetics showed that degradation processes of the four antibiotics followed a pseudo-first-order kinetic model. Antibiotics adsorption onto the nanocomposite surface depended on their electrostatic nature and played an important role when decreasing the initial concentration of antibiotics. In this context, kinetic rates were higher at lower initial levels of organic pollutants, which is a favourable effect from a practical application perspective. On the other hand, a synergistic effect of the available Fe in the nanocomposite was found, contributing to the oxidation of antibiotics by photo-Fenton as a secondary reaction. Then, a magnetic photocatalytic reactor was operated under optimal conditions. The enhanced photonic efficiency of FeO/ZnO in the system, as well as the ease of the magnetic separation and catalyst reusability, indicate the viability of this reactor configuration.
本研究的目的是制备一种新型纳米复合材料（NC），基于 FeO/ZnO，用于消除地表水中的四种持久性抗生素：磺胺甲恶唑、甲氧苄啶、红霉素和罗红霉素。在进行光催化反应器操作之前，评估了 pH 值（3-9）、催化剂浓度（50-800 mg/L）、氧化剂剂量（0-100 mg/L）和不同目标浓度（10-100 µg/L）对催化效率的影响。反应动力学分析表明，四种抗生素的降解过程遵循准一级动力学模型。抗生素在纳米复合材料表面的吸附取决于它们的静电性质，在降低抗生素的初始浓度时起着重要作用。在这种情况下，较低的初始有机污染物水平下的动力学速率更高，这从实际应用的角度来看是有利的。另一方面，发现纳米复合材料中可用的 Fe 具有协同作用，通过光芬顿作为二级反应促进抗生素的氧化。然后，在最佳条件下操作磁性光催化反应器。该系统中 FeO/ZnO 的光子增强效率以及磁性分离和催化剂重复使用的便利性表明了这种反应器配置的可行性。
