基于变频脉冲电沉积法的聚苯胺类复合材料制备及其电吸附四环素类化合物的机理研究

To develop an effective treatment method for the global antibiotic pollution in surface water, activated carbon fiber (ACF) supported polyaniline-based composites (ACF-PANI) are prepared as adsorbents for tetracyclines (TCs) in this electro-adsorption performance and mechanism study. In this project, polyaniline-based conductive polymers (PANI) are electro-deposited on the surface of ACF by the frequency agility pulse method. The properties of PANI including surface morphology, specific surface area, pore structure and surface charge will be regulated by optimizing the hydrochemical and electrochemical conditions in the preparation of ACF-PANI, thus to improve its selective electro-adsorption of TCs. The mechanism on the controlled growth of PANI over the ACF under the optimized conditions will be investigated to provide guidance for optimization of PANI electro-deposition conditions. In the electro-adsorption study, the impacts stemming from the differences between TCs nature, coexisting components in surface water, surface properties of ACF-PANI, the hydrochemical and electrochemical conditions will be evaluated based on the electro-adsorption performance. In addition, the mechanism of TCs' selective electro-adsorption on ACF-PANI will be revealed to support the PANI surface properties regulation in the ACF-PANI preparation. In summary, the research findings of the present project will provide an inspiration and innovative method for the controlled growth of conductive polymers, and expand the ACF-PANI application in the treatment of antibiotic pollution in surface water.

针对目前全球地表水抗生素污染现状，本课题拟采用变频脉冲法，在活性炭纤维基体上电沉积聚苯胺类导电聚合物，制备复合材料；研究四环素类化合物在该复合材料表面的电吸附行为与机理。在复合材料制备过程中，本课题旨在探索变频脉冲电沉积法中水化学、电化学条件的优化，实现聚苯胺类导电聚合物表面形貌、孔道及电化学性质的可控调节，以增强其电吸附四环素类化合物的选择性；阐明优选条件下聚苯胺类导电聚合物在基体上的可控生长机制。在电吸附研究中，探索四环素类化合物间的性质差异、地表水体共存竞争物质、复合材料表面性质、水化学条件以及电化学条件对四环素类化合物电吸附行为的影响；阐明四环素类抗生素在复合材料表面选择性电吸附的机理，为调控复合材料的表面性质提供理论导向。本课题研究成果将为导电聚合物的可控生长提供新的思路和方法，并为拓展该类复合材料在地表水体抗生素污染治理领域的应用提供技术支持。

本项目主要工作内容包括：四环素类抗生素（TCs）在碳化生物质-聚苯胺复合材料、金属基-电致膨胀石墨原位复合材料、生物质吸附材料及传统吸附材料（活性炭、改性树脂）上的（电）吸附行为。研究了材料复合所引发的吸附剂表面结构、物理化学性质变化以及上述变化对TCs电吸附行为的影响；探讨了电吸附体系电极电位、pH值等因素对电吸附性能的影响；探索了生物质吸附材料表面金属（氢氧）氧化物在吸附TCs过程中的作用以及环境水体常见物质对TCs吸附行为的影响；考查了活性炭性质差异、树脂改性及TCs生产废水中常见物质对TCs吸附行为的影响。基于本项目的研究，可得到以下结论：首先，碳化生物质与聚苯胺复合后因赝电容效应电容值大幅提升，对TCs具有良好的电吸附作用；其次，采用电化学方法原位制备金属基-膨胀石墨材料可简化路径，且保持良好的电极性能；再次，生物质吸附材料表面的金属（氢氧）氧化物是TCs吸附过程中的主要作用位点；最后，传统吸附剂（活性炭、改性树脂）经优选或改性后在TCs废水的吸附处理领域仍有较好的应用前景。