Degradation mechanism and kinetic modeling for UV/peroxydisulfate treatment of penicillin antibiotics
Degradation mechanism and kinetic modeling for UV/peroxydisulfate treatment of penicillin antibiotics
复制标题
青霉素抗生素紫外线/过二硫酸盐处理的降解机制和动力学模型
DOI：
10.1016/j.cej.2018.01.137
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发表时间：
2018
影响因子：
15.1
通讯作者：
Qian Yajie
中科院分区：
文献类型：
--
作者：
Zhou Xuefei;Liu D;an;Zhang Yalei;Chen Jiabin;Chu Huaqiang;Qian Yajie
青霉素类抗生素在自然环境中的广泛存在，由于其潜在的诱导抗病基因的作用，引起了人们越来越多的关注。本文研究了紫外光/过硫酸盐（UV/PDS）降解PEN的反应动力学、转化机理和能量效率。硫酸根自由基（SO 4 −radical dot）和羟基自由基（HO radical dot）与青霉素G（PG）、阿莫西林（AMX）和羧苄青霉素（CBN）的二级反应速率常数分别为（3.90-9.32）× 109 M −1·s− 1和（6.67-9.86）× 109 M −1·s−1。采用拟稳态动力学模型，成功地预测了PEN在超纯水中的降解。模拟结果表明，直接光解和间接光解均对PENs的降解有贡献，且随着PDS投加量的增加，间接光解的贡献增大。SO 4 −自由基点是PEN间接光解的主要贡献者。pH值和水基质的影响，包括HCO 3 −，Cl−和天然有机物进行了评估和建模。结合模拟结果，衍生自由基和激发态物种可能产生并参与了PEN的整体降解。在此基础上，对PDS处理过程的每阶电能（EE/O）进行了粗略的计算，以评价PDS处理过程的能量效率。最后，转化产物分析表明，五元环和侧链上的硫醚硫，例如，PG和CBN上的苯环是SO 4 −自由基点的反应位点，而AMX上的伯胺是SO 4 −自由基点的另一个反应位点。
The widespread occurrence of penicillin antibiotics (PENs) in natural environment has raised increasing concerns due to their potential to induce antibiotic-genes. In this study, the degradation of PENs by UV/peroxodisulfate (PDS) process was investigated to determine the reaction kinetics, transformation mechanism and energy efficiency. The second-order rate constants for sulfate radical (SO4−radical dot) and hydroxyl radical (HOradical dot) with PENs, including, pencillin G (PG), amoxicillin (AMX) and carbenicillin (CBN), were determined to be (3.90–9.32) × 109M−1·s−1and (6.67–9.86) × 109M−1·s−1, respectively. A pseudo steady-state kinetic model was employed and successfully predicted the degradation of PENs in ultrapure water. The modeling results revealed that both direct and indirect photolysis contributed to PENs degradation, and the contribution of indirect photolysis increased with the increase of PDS dosage. SO4−radical dot was the major contributor to PENs indirect photolysis. The effect of pH and water matrices, including HCO3−, Cl−and natural organic matter were evaluated and modeled. Combined with the modeling results, the derived radicals and excited species were likely generated and involved in the overall degradation of PENs. Based on the developed model, we gave a roughly calculation of electrical energy per order (EE/O) to evaluate the energy efficiency of PDS treatment processes. Finally, the transformation product analysis indicated that the thioether sulfur on the five-membered ring and the side chain, e.g., benzene ring on PG and CBN were the reactive sites for SO4−radical dot, while the primary amine was another reactive site for SO4−radical dot on AMX.