Ti/PbO2电化学法降解废水中三种氟喹诺酮类抗生素

采用Ti/PbO₂阳极电解3种典型的氟喹诺酮类抗生素（诺氟沙星、甲磺酸培氟沙星与盐酸环丙沙星）废水，通过优化pH值、电解质浓度条件，分析3种抗生素的去除效果、降解过程和产物.结果表明电化学法对3种氟喹诺酮类抗生素均有明显的降解效果，电解240min下的最优降解条件为pH值控制在7.8~8.0，电解质硫酸钠投加量为0.04mol/L.在最优条件下3种抗生素的去除率均大于97%，降解过程均符合一级动力学方程，UV₂₅₄值的去除率较高（去除率大于67%），处理后废水的芳香度和SUVA值明显下降.液质联用分析结果和文献调研显示，电解有机产物主要通过脱氟、哌嗪环的转化和喹啉环的转化这三个途径生成，且随电解时间增加呈现先增后减的趋势，同时产生F^-、NH₄⁺和NO₃^-等无机物.Ti/PbO₂阳极能有效电解废水中3种典型氟喹诺酮类抗生素，可用作生物处理等方法的预处理.

Degradation of three fluoroquinolones antibiotics in wastewater by Ti/PbO2 electrochemical method

Ti/PbO₂ electrochemical oxidation mechanisms of three typical fluoroquinolone antibiotics (FQNs) in wastewater were studied. The effects of pH, electrolyte and electrolysis time were optimized, and the removal efficiency, degradation kinetics and products of norfloxacin (NOR), Pefloxacin Mesylate (PEF), and ciprofloxacin (CIP) were explored. The results revealed that, after 240minutes, Ti/PbO₂ electrodes could remove more than 97% of FQNs under the given conditions (initial pH 7.8~8.0, [Na₂SO₄]0: 0.04mol/ L). Moreover, the degradation rates were well fit with the first-order kinetic equation. The decrease percentages of UVA₂₅₄ value were larger than 67%. A significant decrease in SUVA values and aromaticity after degradation was also observed. HPLC-MS/MS was used to confirm the degradation intermediates and three possible degradation mechanisms were proposed based on the oxidation products. The intermediates were mainly produced by defluorination,piperazine ring transformation, and quinoline ring transformation.Furthermore, the electrolytic products had a tendency to increase at first and then decrease over time. Some inorganic products, such as F^-, NH₄⁺, and NO₃^- were founded in the wastewater after treatment. Our results indicated that the Ti/PbO₂ electrodes was effective and proved to be a promising method for the pretreatment of fluoroquinolone antibiotics in wastewater.