Competitive adsorption of ofloxacin enantiomers to goethite: experiments and modelling

IF 2 4区环境科学与生态学 Q3 CHEMISTRY, ANALYTICAL

Environmental Chemistry Pub Date : 2021-01-08 DOI:10.1071/EN20123

X. Qin, Xiaofei Zhong, Ping Du, Juan Chen, J. Jia, Ying He, Fei Liu, L. Weng

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引用次数: 5

Abstract

Environmental context The concentration, types and distribution of antibiotics in soils can have environmental effects and can be modelled using laboratory systems. Adsorption of ofloxacin (OFL) and levofloxacin (LEV) enantiomers to goethite can probe this behaviour and each binds differently to the solid phase. The different behaviour of LEV and OFL in relation to solid-solution partitioning will affect their environmental fate. Abstract The adsorption of ofloxacin enantiomers, namely levofloxacin (LEV) and ofloxacin (OFL), to goethite was investigated using batch experiments. Structural information of aqueous and adsorbed LEV or OFL was obtained with ultraviolet–visible (UV-Vis), three-dimensional excitation–emission matrix (EEM) and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopic methods. The results indicated that LEV molecules formed a bridging bidentate complex (≡(FeO)2–LEV) with the surface of goethite, and OFL formed a monodentate complex (≡FeO–OFL). The adsorption of OFL to goethite was stronger than that of LEV, owing to differences in their physicochemical properties and bonding modes. The adsorption of LEV and OFL to goethite in single systems was well simulated using the charge distribution multi-site complexation (CD-MUSIC) model, but their adsorption in the LEV–OFL–goethite systems was overestimated at pH ~5.2 and high concentrations of LEV–OFL mixture (19.59 μM), in which the predicted amounts of adsorbed LEV and OFL were higher (20.0, 30.8 %) than the experimental results. Compared with the unprotonated LEV or OFL, the protonated (>99.9 %) ones were mainly adsorbed to the surface of goethite, and the single species may be used during their following modelling.

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氧氟沙星对映体在针铁矿上的竞争性吸附:实验和模拟

土壤中抗生素的浓度、类型和分布可产生环境影响，并可使用实验室系统进行模拟。氧氟沙星(OFL)和左氧氟沙星(LEV)对映体在针铁矿上的吸附可以探测到这种行为，并且它们与固相的结合方式不同。LEV和OFL在固溶分配方面的不同行为将影响它们的环境命运。摘要采用批量实验研究氧氟沙星对映体左氧氟沙星(LEV)和氧氟沙星(OFL)在针铁矿上的吸附。采用紫外-可见(UV-Vis)、三维激发-发射矩阵(EEM)和衰减全反射傅里叶变换红外(ATR-FTIR)光谱方法获得了水溶液和吸附的LEV或OFL的结构信息。结果表明，LEV分子与针铁矿表面形成桥接的双齿络合物(≡(FeO) 2-LEV)， OFL分子形成单齿络合物(≡FeO - OFL)。由于其物理化学性质和键合模式的差异，OFL对针铁矿的吸附比LEV强。采用电荷分布多位点络合(CD-MUSIC)模型很好地模拟了单体系中LEV和OFL对针铁矿的吸附，但在pH ~5.2和高浓度LEV - OFL混合物(19.59 μM)条件下，LEV和OFL在LEV - OFL -针铁矿体系中的吸附量被高估了，其中LEV和OFL的预测吸附量分别比实验结果高20.0%和30.8%。与未质子化的LEV或OFL相比，质子化的(> 99.9%)主要吸附在针铁矿表面，并且在其后续建模中可以使用单一种。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Environmental Chemistry 环境科学-分析化学

CiteScore

4.50

自引率

0.00%

发文量

审稿时长

2.7 months

期刊介绍： Environmental Chemistry publishes manuscripts addressing the chemistry of the environment (air, water, earth, and biota), including the behaviour and impacts of contaminants and other anthropogenic disturbances. The scope encompasses atmospheric chemistry, geochemistry and biogeochemistry, climate change, marine and freshwater chemistry, polar chemistry, fire chemistry, soil and sediment chemistry, and chemical aspects of ecotoxicology. Papers that take an interdisciplinary approach, while advancing our understanding of the linkages between chemistry and physical or biological processes, are particularly encouraged. While focusing on the publication of important original research and timely reviews, the journal also publishes essays and opinion pieces on issues of importance to environmental scientists, such as policy and funding. Papers should be written in a style that is accessible to those outside the field, as the readership will include - in addition to chemists - biologists, toxicologists, soil scientists, and workers from government and industrial institutions. All manuscripts are rigorously peer-reviewed and professionally copy-edited. Environmental Chemistry is published with the endorsement of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Academy of Science.