Enhanced Cu(II)-mediated fenton-like oxidation of antimicrobials in bicarbonate aqueous solution: Kinetics, mechanism and toxicity evaluation
Enhanced Cu(II)-mediated fenton-like oxidation of antimicrobials in bicarbonate aqueous solution: Kinetics, mechanism and toxicity evaluation
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碳酸氢盐水溶液中抗菌剂增强 Cu(II) 介导的类芬顿氧化：动力学、机制和毒性评估
DOI：
10.1016/j.envpol.2019.05.148
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发表时间：
2019-09-01
影响因子：
8.9
通讯作者：
Gao, Shixiang
中科院分区：
文献类型：
--
作者：
Peng, Jianbiao;Zhang, Chaonan;Gao, Shixiang
人们越来越关注开发去除氯芬 (CF) 和二氯芬 (DCF) 的新技术，这两种物质是一般清洁和消毒用抗菌剂中的活性剂。本研究探讨了碳酸氢盐 (HCO3-) 对 Cu(II) 介导的类芬顿系统 Cu2+/H2O2 中 CF 和 DCF 降解的显着影响。我们的结果表明，HCO3-可能发挥双重作用：1）作为稳定Cu（II）的配体，形成可溶性[Cu-II（HCO3-）（S）]（+）物质以催化H2O2产生羟基自由基（中心点OH）和超氧离子（O-2（-中心点））和2）作为中心点OH清除剂。此外，还评估了 CF 和 DCF 的反应动力学、机制和中间体。在优化浓度 4 mM 的 HCO3- 存在下，CF 和 DCF 的表观速率常数分别提高了 8.5 和 5.5 倍。基于中间体鉴定和前沿电子密度（FED）计算，初步提出了相关的反应途径，包括C-C断裂、单羟基化或多重羟基化以及偶联反应。此外，经生态结构活动关系（ECOSAR）程序评估，经Cu2+/H2O2-HCO3-系统处理后，CF和DCF的水生毒性显着降低。这些发现为 Cu(II) 介导的反应提供了新的见解，以更好地了解富含碳酸盐的水中有机污染物的环境命运。 (C) 2019 Elsevier Ltd. 保留所有权利。
Increasing attention has been attracted in developing new technologies to remove chlorofene (CF) and dichlorofene (DCF), which were active agents in antimicrobials for general cleaning and disinfecting. This study investigated the significant influences of bicarbonate (HCO3-) on the degradation of CF and DCF in the Cu(II)-mediated Fenton-like system Cu2+/H2O2. Our results indicate that HCO3- may play a dual role to act 1) as a ligand to stabilize Cu(II), forming soluble [Cu-II(HCO3-)(S)](+) species to catalyze H2O2 producing hydroxyl radical (center dot OH) and superoxide ion (O-2(-center dot)) and 2) as a center dot OH scavenger. Furthermore, the reaction kinetics, mechanisms, and intermediates of CF and DCF were assessed. The apparent rate constants of CF and DCF were enhanced by a factor of 8.5 and 5.5, respectively, in the presence of HCO3- at the optimized concentration of 4 mM. Based on the intermediate identification and frontier electron densities (FEDs) calculations, the associated reaction pathways were tentatively proposed, including C-C scission, single or multiple hydroxylation, and coupling reaction. In addition, significant reduction in the aquatic toxicity of CF and DCF was observed after treatment with Cu2+/H2O2-HCO3- system, evaluated by Ecological Structure Activity Relationships (ECOSAR) program. These findings provide new insights into Cu(II)-mediated reactions to better understand the environmental fate of organic contaminants in carbonate-rich waters. (C) 2019 Elsevier Ltd. All rights reserved.