Adsorption of Enrofloxacin on montmorillonite: two-dimensional correlation ATR/FTIR spectroscopy study.
Adsorption of Enrofloxacin on montmorillonite: two-dimensional correlation ATR/FTIR spectroscopy study.
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DOI：
10.1016/j.jcis.2012.09.039
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发表时间：
2013-01
影响因子：
9.9
通讯作者：
Wei Yan;Jianfeng Zhang;C. Jing
中科院分区：
文献类型：
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作者：
Wei Yan;Jianfeng Zhang;C. Jing
恩诺沙星(ENR)在矿物表面的吸附决定了ENR在环境中的去向和迁移。利用原位−红外光谱和二维相关分析研究了环氧氯丙烷在蒙脱土上的吸附过程以及溶解有机物(DOMS)对环氧氯丙烷/蒙脱土相互作用的影响。在3400-2900 cm−1区观察到负峰，这是由于蒙脱石表面失去水合质子所致。吸附分子的主要特征峰在1800-1100 cm−-1范围内得到分辨。2D-COS的结果表明，吸附过程是由水合质子在蒙脱土表面的相互作用引发的，不同的pH决定了ENR分子的不同部分。ENR的吸附机理主要是酸性条件下的阳离子交换、中性条件下的电荷中和和碱性条件下的质子转移。DOM能与溶解的ENR上的哌嗪胺基团相互作用，从而改变了ENR分子与蒙脱土表面的作用顺序。静电相互作用是DOM与溶解的ENR相互作用的主要驱动力。H-供体-受体相互作用和π−π相互作用也可能是这种相互作用的原因。通过本研究，加深了我们对ENR等离子有机污染物在土壤系统中吸附机理的理解。
Adsorption of Enrofloxacin (ENR) on minerals dominates the fate and transport of ENR in the environment. In this study, the sorption process of ENR on montmorillonite and the impact of dissolved organic matters (DOMs) on ENR-montmorillonite interactions were investigated using in situ ATR−FTIR spectroscopy and two-dimensional correlation analysis (2D-COS). Negative peaks were observed in the 3400–2900cm−1region due to the loss of hydrated protons at montmorillonite surfaces. The primary characteristic peaks of adsorbed ENR molecules were resolved in the 1800–1100cm−1range. The results of 2D-COS suggested the sorption process was initiated by the interaction of hydrated protons on montmorillonite surfaces with diverse moieties of ENR molecules depending on pH. The sorption mechanism of ENR was mainly cation exchange at acidic condition, charge neutralization at neutral condition, and proton transfer at alkaline condition. DOM could interact with piperazinyl amine groups of dissolved ENR, which changed the interaction sequence of ENR molecule with montmorillonite surfaces. Electrostatic interaction was the predominant driving force for the interaction between DOM and dissolved ENR. H-donor–acceptor interaction and π−π interaction may also be responsible to this interaction. Insights gained from this study improve our understandings on sorption mechanism of ENR and similar ionic organic pollutants in soil systems.