Key Laboratory of Groundwater Resources and Environment of the Ministry of Education, College of Environment and Resources, Jilin University, 2519 Jiefang Road, Changchun, 130021, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Jan;25(3):2466-2475. doi: 10.1007/s11356-017-0518-9. Epub 2017 Nov 10.
Metronidazole (MNZ) is widely used in clinical applications and animal feed as an antibiotic agent and additive, respectively. Widespread occurrence of MNZ in wastewater treatment and hospital effluents has been reported. In this study, the mechanism of MNZ degradation in aqueous solutions via thermally activated persulfate (TAP) process was established under different conditions. The kinetic model was derived for MNZ degradation and followed pseudo-first-order reaction kinetics and was consistent with the model fitted by experimental data (R > 98.8%). The rate constant increased with the initial dosage of persulfate, as well as the temperature, and the yielding apparent activation energy was 23.9 kcal mol. The pH of the solutions did not have significant effect on MNZ degradation. The degradation efficiency of MNZ reached 96.6% within 180 min for an initial MNZ concentration of 100 mg L under the optional condition of [PS] = 20 mM, T = 60 °C, and unadjusted pH. [Formula: see text] and HO were confirmed using electron paramagnetic resonance (EPR) spectra during TAP process. Radical quenching study revealed that [Formula: see text] was mainly responsible for MNZ degradation at an unadjusted pH. MNZ mineralization evaluation showed that the removal efficiency of total organic carbon (TOC) reached more than 97.2%.
甲硝唑（MNZ）广泛应用于临床和动物饲料，分别作为抗生素和添加剂。已有报道表明，MNZ 在废水处理和医院废水中广泛存在。在这项研究中，建立了在不同条件下通过热激活过硫酸盐（TAP）过程在水溶液中降解 MNZ 的机制。推导了 MNZ 降解的动力学模型，遵循准一级反应动力学，与实验数据拟合的模型一致（R>98.8%）。速率常数随过硫酸盐的初始剂量、温度的增加而增加，表观活化能为 23.9 kcal/mol。溶液的 pH 对 MNZ 降解没有显著影响。在初始 MNZ 浓度为 100 mg/L、可选条件下[PS] = 20 mM、T = 60°C、未调节 pH 时，MNZ 的降解效率在 180 min 内达到 96.6%。在 TAP 过程中，使用电子顺磁共振（EPR）光谱证实了[Formula: see text]和 HO 的存在。自由基猝灭研究表明，在未调节 pH 条件下，[Formula: see text]是 MNZ 降解的主要原因。MNZ 矿化评价表明，总有机碳（TOC）的去除效率达到 97.2%以上。
