硫酸根自由基降解氟喹诺酮抗生素动力学模型构建

Establishment and analysis of kinetic models for degradation of fluoroquinolones antibiotics by sulfate radical

针对水环境中广泛残留的氟喹诺酮类抗生素污染问题,采用热激活过硫酸盐方式降解3种典型氟喹诺酮抗生素(环丙沙星、诺氟沙星、恩诺沙星),考察其在不同pH下的降解情况,构建相关自由基动力学氧化模型,并将数学模型与实验数据相耦合计算体系中特征自由基的浓度及目标物拟二级动力学反应常数。研究结果表明:建立的模型能够较好地描述氟喹诺酮微观反应动力学,反应体系中·SO_4^-及·HO浓度受pH影响较大,环丙沙星、诺氟沙星、恩诺沙星与·SO_4^-反应的二级动力学常数分别为6.96×107±2.31,2.52×10~7±4.47和8.55×10~7±1.98L/(mol·s)。

To solve the pollution issue caused by the pervasive residual of fluoroquinolones antibiotics, thermally activated persulfate was used to degrade three typical fluoroquinolones（i.e., ciprofloxacin, norfloxacin, enrofloxacin）. The effect of p H on the degradation was investigated and kinetic oxidation models for free radicals were established. By coupling oxidation models with experimental results, the concentration of free radicals and the pseudo-second-order reaction constants for targets were calculated. The results show that the established high ordered equations can well describe the microreaction kinetics and pH has a significant effect on the concentrations of ·SO4^-and ·HO. Meanwhile, the pseudo-second-order reaction constants with ·SO4^-are 6.96×107±2.31,2.52×107±4.47 and 8.55×10^7±1.98 L/（mol·s） for ciprofloxacin, norfloxacin and enrofloxacin, respectively.