海藻酸钠/石墨烯双网络纳米复合凝胶球的构建及其对重金属和抗生素吸附机制研究

Heavy metal-antibiotic compound pollution has caused widespread concerns, with the development of scaled livestock and poultry breeding industry. Adsorption separation technology has broad application prospects in pollution control; and development of new and efficient high-performance adsorbents is the key factor to improve the adsorption process. This project uses graphene and sodium alginate to construct an organic/inorganic double-network and nanocomposite gel bead adsorbent to efficiently remove heavy metals and antibiotics. Graphene has the advantages of high specific surface area, strength, and thermal stability; and sodium alginate has good functionality, biocompatibility and easy to be modified. By combining the graphene and sodium alginate, we can easily solve the separation and aggregation problems of efficient carbon nano-adsorbents, and effectively improve the swelling performance, alkali/salt resistance and strength of gel beads. We will investigate the relationships of micro/macro structure, interface process and adsorption characteristics to understand the mechanism of the regulation of gel interface features and to improve adsorption performance of gel. Synchrotron radiation and other surface analysis techniques were used to investigate adsorption mechanism in the co-existence of heavy metals and antibiotics, to establish adsorption model on molecular level, and to illuminate the adsorption mechanism of between gel surface and polluants under conbined pollutants. The project will explore new ideas and methods for gel adsorbent designed by carbon nano-material in the compound pollution control, to explain and predict the adsorption in the real water environment, and to provide the theoretical and technical foundation for the removal of compound pollution in water supply and sewage treatment.

抗生素和重金属复合污染问题随着畜禽养殖业规模化发展，引起广泛关注。吸附分离技术在污染治理方面具有广阔应用前景，研发高效吸附剂是决定高效能吸附处理过程的关键因素。本课题采用石墨烯与海藻酸钠构建无机/有机双网络纳米复合凝胶球，实现重金属和抗生素高效去除，兼顾石墨烯高比表面积、高强度和热稳定性以及海藻酸钠的功能性和可修饰性，解决碳纳米吸附剂易团聚和难分离难题，有效改善高分子凝胶球溶胀、耐碱/盐及强度等综合性能。阐明凝胶球“微/宏结构”-“界面过程”-“吸附特性”之间的构效关系，为调控凝胶表界面特性并提高吸附性能提供依据；利用同步辐射等表面分析技术，开展复合污染条件下凝胶球吸附机理研究，建立分子水平上的吸附模型，明晰凝胶球表面与污染物间作用机制；探索碳纳米材料构建三维宏观凝胶在复合污染治理中的新思路和新方法，解释和预测实际水体中的吸附现象，为给水和污水处理中去除复合污染物提供理论指导和技术支持。

作为高强度、高性能的代表性高分子材料，近年来具有优异机械性能的双网络凝胶受到广泛关注，但是其在吸附领域的应用研究尚不深入。海藻酸钠与石墨烯在吸附中均具有良好的应用潜力，且均可通过一定方法制备成为三维水凝胶，将两者制备为双网络凝胶有望进一步提高吸附性能，将双网络凝胶应用于吸附中也有助于拓宽双网络凝胶的实际应用范围。本课题利用天然生物大分子海藻酸钠与纳米材料石墨烯制备出新型双网络纳米复合凝胶，研究了双网络的形成机理并对比了单、双网络性能的差异，以水中几种典型污染物作为目标污染物探讨了双网络凝胶的吸附性能，并通过改性进一步提高了吸附性能、深化吸附机理研究。本项目实现重金属和抗生素高效去除，兼顾石墨烯高比表面积、高强度和热稳定性以及海藻酸钠的功能性和可修饰性，解决碳纳米吸附剂易团聚和难分离难题，有效改善高分子凝胶球溶胀、耐碱/盐及强度等综合性能，并阐明凝胶球“微/宏结构”-“界面过程”-“吸附特性”之间的构效关系，为调控凝胶表界面特性并提高吸附性能提供依据；本项目研究结果对双网络凝胶的构建及其在去除水中污染物的应用中具有一定的理论指导意义，在参考此研究结果的基础上有望进一步拓展双网络凝胶的应用领域。项目执行期内发表SCI论文共计24篇，其中包括Environmen. Sci. & Tech.（2篇），Nano Letters，J. Mater. Chem. A （Review），Chem. Eng. J. （4篇），Nanoscale等期刊，中科院一区论文总计13篇，申请中国发明专利共计8项，其中4项授权。