Many studies have proved that montmorillonite (Mt) has good adsorption properties for some antibiotic pharmaceuticals, but the detailed research on the microscopic sorption mechanism is very limited from the atomic level. In the present work, Mt was chosen as an adsorbent for common emerging contaminant-ciprofloxacin (CIP) to investigate the essence of the interaction between Mt and different CIP species at different pH. X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) characterization after adsorption under different pH were utilized to explore the difference of adsorption mechanism with the changed pH. Especially outstanding, for the first time, Molecular dynamics simulation (MD) was carried out to investigate the arrangement and dynamic behavior of cationic CIP in the interlayer of Mt, Multiwfn wave function analysis program was performed to quantitatively analyze the molecular surface electrostatic potential (ESP) distribution of different CIP species to evaluate the electrostatic interaction. Furthermore, for the first time, Hirshfeld surface analysis and independent gradient model (IGM) analysis were applied to probe and visualize the interaction sits between Mt and CIP zwitterion(CIP^+/−) or CIP anion (CIP-), which can reveal the adsorption mechanism of Mt for CIP^+/− and CIP- from the atomic level microscopic perspective.

许多研究已经证明，蒙脱石（Mt）对某些抗生素药物具有良好的吸附性能，但是从原子水平上对微观吸附机理的详细研究非常有限。在目前的工作中，选择了Mt作为常见的新兴污染物环丙沙星（CIP）的吸附剂，以研究Mt与不同CIP物种在不同pH下相互作用的本质。利用X射线衍射（XRD）和傅立叶变换红外光谱（FTIR）表征了不同pH下吸附后的吸附机理，探讨了pH变化对吸附机理的影响。特别杰出的是，首次进行了分子动力学模拟（MD），以研究阳离子CIP在Mt夹层中的排列和动力学行为，执行Multiwfn波函数分析程序来定量分析不同CIP种类的分子表面静电势（ESP）分布，以评估静电相互作用。此外，首次使用Hirshfeld表面分析和独立梯度模型（IGM）分析来探测和可视化Mt和CIP两性离子（CIP）之间的相互作用。^+/-）或CIP阴离子（CIP-），其可以揭示万吨的用于CIP的吸附机构^+/-从原子水平微观的视角和CIP-。