Department of Physical Chemistry, School of Chemistry, University College of Science, University of Tehran, Tehran, 14155, Iran.
Environ Sci Pollut Res Int. 2018 Jan;25(3):2528-2537. doi: 10.1007/s11356-017-0687-6. Epub 2017 Nov 10.
Recently, pharmaceutically active compounds including antibiotics have been detected in drinking water at very low levels, mostly nanogram/liter concentrations, proposing that these materials were unaffected by water treatment processes. Adsorption processes were suggested to play a significant role in the removal of antibiotics. In this study, the adsorption behavior of doxycycline (DC) in aqueous solution was evaluated. The four factors influencing the adsorption of DC onto graphene nanosheet (GNS) were studied. The results showed that initial pH ∼ 6 to 7 and contact time ∼ 200 min are optimum. The monolayer adsorption capacity was reduced with the increasing temperature from 25 to 45 °C. Nonlinear regressions were carried out to define the best fit model for every system. Among various models, the Hill isotherm model represented the equilibrium adsorption data of antibiotics while the kinetic data were well fitted by the Elovich kinetic model. The maximum adsorption capacity (q ) was 110 mg.g, obtained from the Hill equation. Semiempirical molecular orbital theory was used to investigate the molecular interaction of the adsorption system. The experiments and semiempirical computation have systematically demonstrated that DC could be adsorbed onto GNS by π- π and electrostatic interactions. It was shown that there is a good compromise with the experimental results. Graphical abstract Insights into doxycycline adsorption onto graphene nanosheet: quantum mechanics, thermodynamics, and kinetic study.
最近，在饮用水中以非常低的水平（主要为纳克/升浓度）检测到了包括抗生素在内的具有药用活性的化合物，这表明这些物质未受水处理过程的影响。吸附过程被认为在去除抗生素方面发挥了重要作用。在这项研究中，评估了盐酸多西环素（DC）在水溶液中的吸附行为。研究了影响 DC 吸附到石墨烯纳米片（GNS）上的四个因素。结果表明，初始 pH 值约为 6 到 7，接触时间约为 200 分钟是最佳条件。吸附容量随温度从 25°C 增加到 45°C 而降低。进行了非线性回归以确定每个系统的最佳拟合模型。在各种模型中，Hill 等温线模型表示抗生素的平衡吸附数据，而 Elovich 动力学模型则很好地拟合了动力学数据。从 Hill 方程中得到最大吸附容量（q ）为 110mg·g。半经验分子轨道理论用于研究吸附体系的分子相互作用。实验和半经验计算系统地证明了 DC 可以通过π-π 和静电相互作用吸附到 GNS 上。结果表明，实验结果与理论结果有很好的一致性。
