多层环糊精-氧化石墨烯骨架薄膜的制备及其去除水中微污染物的效能与机制研究

Micropollutants are detected in most of water resources in China and it is difficult to removal from aqueous solutions, especially for the conventional adsorption technology. The multilayer Cyclodextrin-graphene oxide (CD-GO) thin film adsorbent is prepared with excellent benefits of open network structure morphology, selective adsorption of micropollutants and good separation characteristics. The influence factors and corresponding control measures of thin film preparation will be investigated. The structure, morphology, element and properties of the as-prepared thin film will be characterized. The relationship of the thin film microstructure-chemical properties-adsorption efficiency will be illustrated. The influence of the characteristics and concentrations of the selected micropollutants, initial pH of the solution and co-existing ions on the adsorption efficiency will be studied. The models of adsorption kinetics, thermodynamics and isotherms behavior will be investigated, along with the corresponding adsorption mechanism and reaction pathway. We will also test the stability and repeatability of the as-prepared thin film. In all, from the scientific and application aspect, the results expected in this proposal will provide theoretical information on the prospective preparation and application of CD-GO thin film in the removal of micropollutants from aqueous solutions.

针对我国水源中普遍存在的微污染物难处理的问题，以及常规吸附处理技术的不足，本项目提出以碳纳米材料氧化石墨烯为承受面层，环境友好型环糊精为骨架，研发制备具有开放式网状结构形貌、选择性吸附微污染物和优良分离特性的新型多层环糊精-氧化石墨烯骨架薄膜吸附剂，重点处理水中典型的低剂量、高毒性微污染物。探明影响薄膜制备的因素及调控措施，从结构、形貌、成分及性能方面对薄膜进行表征，阐明薄膜微观结构-化学性质-吸附效能之间的关系；研究微污染物特性和浓度、溶液pH、共存离子等条件对吸附效能的影响；建立吸附动力学、吸附热力学和等温吸附线模型进而探讨薄膜对微污染物的吸附行为；阐明薄膜吸附微污染物反应机制和途径；验证薄膜的稳定性和重复利用性。本项目为水中微量污染物的去除以及新型多层环糊精-氧化石墨烯骨架薄膜的制备和应用提供技术支撑，具有重要的科学意义。

针对水中药品和个人护理品末端处理的问题，以纳米碳材料石墨烯为承受面层，环境友好型环糊精为骨架，制备多种环糊精/石墨烯骨架薄膜吸附剂。并研究了其对水中双氯芬酸钠、西咪替丁和磺胺甲恶唑的去除效能和机制，为水中PPCPs的去除提供科学建议和参考。本研究成功制备了环糊精/氧化石墨烯复合物、涂覆铜箔基底、提拉镀膜和真空抽滤法CD/GO薄膜，所制备的复合物和薄膜具有明显的多层状结构且每层分布较为均匀，表面平滑完整，具有良好的水稳定性。吸附剂表面带有大量负电荷，随着pH值的升高，吸附剂对CTD、SMZ和DCF的吸附量显著降低。随着离子强度的增加，吸附量逐渐降低，二价离子的抑制效果明显强于一价离子。吸附剂对CTD、SMZ和DCF的吸附在速率较快，动力学拟合结果较好符合准一级动力学模型。吸附符合Langmuir模型，属于单分子层吸附，且是一个放热过程。吸附剂对PPCPs的吸附机理主要是物理吸附和化学吸附共同作用的结果。