Department of Civil & Environmental Engineering and Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Environ Sci Technol. 2010 Aug 15;44(16):6416-22. doi: 10.1021/es101331j.
The ubiquitous occurrence of antibiotics in aquatic environments raises concerns about potential adverse effects on aquatic ecology and human health, including the promotion of increased antibiotic resistance. This study examined the oxidation of three widely detected antibiotics (ciprofloxacin, lincomycin, and trimethoprim) by potassium permanganate [KMnO(4); Mn(VII)]. Reaction kinetics were described by second-order rate laws, with apparent second-order rate constants (k(2)) at pH 7 and 25 degrees C in the order of 0.61 +/- 0.02 M(-1) s(-1) (ciprofloxacin) < 1.6 +/- 0.1 M(-1) s(-1) (trimethoprim) < 3.6 +/- 0.1 M(-1) s(-1) (lincomycin). Arrhenius temperature dependence was observed with apparent activation energies (E(a)) ranging from 49 kJ mol(-1) (trimethoprim) to 68 kJ mol(-1) (lincomycin). Rates of lincomycin and trimethoprim oxidation exhibited marked pH dependences, whereas pH had only a small effect on rates of ciprofloxacin oxidation. The effects of pH were quantitatively described by considering parallel reactions between KMnO(4) and individual acid-base species of the target antibiotics. Predictions from a kinetic model that included temperature, KMnO(4) dosage, pH, and source water oxidant demand as input parameters agreed reasonably well with measurements of trimethoprim and lincomycin oxidation in six drinking water utility sources. Although Mn(VII) reactivity with the antibiotics was lower than that reported for ozone and free chlorine, its high selectivity and stability suggests a promising oxidant for treating sensitive micropollutants in organic-rich matrices (e.g., wastewater).
环境中普遍存在抗生素，这引起了人们对其可能对水生生态和人类健康产生不利影响的关注，包括促进抗生素耐药性的增加。本研究考察了高锰酸钾[KMnO4；Mn(VII)]氧化三种广泛检测到的抗生素（环丙沙星、林可霉素和甲氧苄啶）的情况。反应动力学符合二级反应规律，在 pH 7 和 25°C 下，表观二级速率常数（k2）的顺序为 0.61 ± 0.02 M-1 s-1（环丙沙星）<1.6 ± 0.1 M-1 s-1（甲氧苄啶）<3.6 ± 0.1 M-1 s-1（林可霉素）。观察到阿仑尼乌斯温度依赖性，表观活化能（Ea）范围从 49 kJ mol-1（甲氧苄啶）到 68 kJ mol-1（林可霉素）。林可霉素和甲氧苄啶的氧化速率表现出明显的 pH 依赖性，而 pH 对环丙沙星氧化速率的影响较小。通过考虑高锰酸钾与目标抗生素的各个酸碱物种之间的平行反应，定量描述了 pH 的影响。将动力学模型的预测值作为输入参数，包括温度、高锰酸钾用量、pH 和原水氧化剂需求，与 6 个饮用水处理厂中甲氧苄啶和林可霉素氧化的测量值吻合较好。虽然 Mn(VII)与抗生素的反应性低于臭氧和自由氯的反应性，但由于其高选择性和稳定性，Mn(VII)有望成为处理富含有机物基质（例如废水）中敏感微量污染物的有前途的氧化剂。
