基于仿生涂层的分离、吸附、催化多功能膜的制备机理及其应用基础研究

Due to the increasing public attention on water security as well as the more stringent emission standards in recent years, membrane technology has more and more opportunities in the water treatment while the new demands on the membrane performance have emerged. In order to improve the removal efficiency of trace contaminants in wastewater by membrane filtration, a novel concept of multi-functional membrane with separation, adsorption and catalysis abilities is proposed for the first time in this project, and by using commercial ultrafiltration and nanofiltration membranes as pristine membranes, the novel multi-functional membrane will be prepared via fouling-induced enzyme immobilization and bio-inspired dopamine coating. For this membrane, the partial retention of contaminants by the membrane skin layer can greatly lower the catalytic burden on enzymes in the membrane, and the adsorption of contaminants by the coating layer can prolong its contact time with enzymes and improve the conversion efficiency. Take laccase as an example, we attempt to clarify the mechanisms of enzyme immobilization in the polydopamine coating layer, and based on this, the permeability, enzyme loading and adsorption capacity of this multi-functional membrane will be improved by optimizing the process parameters during enzyme immobilization and by tuning the morphology and structure of the bio-inspired coating layer. The prepared multi-functional membrane will be applied to remove antibiotics (tetracycline) in the wastewater, and the mechanisms of synergistic interactions of the multi-functions (separation, adsorption and catalysis) will be clarified. By exploring the adsorption and desorption of the bio-inspired polydopamine coating layer, the highly efficient reuse of the multi-functional membrane will be achieved. The outcome of this project will provide new methodology for the fabrication of multi-functional membranes and for the advanced wastewater treatment.

随着近年来公众对水安全的日益关注以及污水排放标准的愈加严格，膜分离技术的应用迎来了新的机遇，同时也对分离膜的性能提出了新的要求。为了提高膜过滤对水中微量污染物的去除效果，本项目提出分离、吸附、催化多功能膜的新概念，以商品化超滤和纳滤膜为基膜，采用逆向膜富集酶固定化和多巴胺仿生粘合封装技术实现新型多功能膜的制备。新型多功能膜的分离功能可大幅度降低酶催化负荷，吸附功能可增加底物与酶的接触反应时间。本项目拟以漆酶为研究对象，阐明聚多巴胺涂层对漆酶的固定化机制，通过对固定化过程参数的优化和对仿生涂层形态结构的调控，提高多功能膜的渗透通量、载酶量和吸附能力。拟将制备的多功能膜应用于抗生素（四环素）的去除，揭示膜对抗生素的分离、吸附、催化多功能协同作用机制。通过探索聚多巴胺仿生涂层的吸附解吸过程，实现多功能膜的高效重复使用。本项目的顺利实施，将为多功能膜的制备以及深度废水处理提供新思路。

随着近年来公众对水安全的日益关注以及污水排放标准的愈加严格，膜分离技术的应用迎来了新的机遇，同时也对分离膜的性能提出了新的要求。为了提高膜过滤对水中微量污染物的去除效果，本项目提出分离、吸附、催化多功能膜的新概念，以商品化纳滤膜为基膜，采用逆向膜富集酶固定化和多巴胺仿生粘合封装技术实现新型多功能膜的制备。该项目以漆酶为研究对象，阐明了聚多巴胺涂层对漆酶的固定化机制为包埋、静电/疏水吸附和共价偶联，通过对固定化过程参数的优化和对仿生涂层形态结构的调控，提高多功能膜的渗透通量、载酶量和吸附能力。新型多功能膜的分离功能可大幅度降低酶催化负荷，吸附功能可增加底物与酶的接触反应时间，同时生物酶的催化功能打破“吸附饱和”的限制。该过程中三种功能互相促进，其协同效应大大提高了整体效果。相比于商品化纳滤分离膜，多功能膜对水中微量污染物（如双酚A）的去除率提高了200%。通过对聚多巴胺涂层进行分子设计，提高载酶量、酶活力和稳定性，实现多功能膜的重复使用，9 次重复使用后对BPA 的去除率仍可保持在75%以上。该多功能膜可实现连续运行，具有作为饮用水净化终端设备的潜力，同时可应用于水中微量污染物的在线检测与超标预警。同时利用膜色谱介质捕集发酵液中的漆酶制备多功能膜，通过提高漆酶纯度改善多功能膜的渗透性和催化活性，并将多功能膜应用于黄曲霉毒素B1的吸附和降解，多功能膜实现了酶催化、酶固定化、酶缓释、膜吸附和碱处理的结合，大大提高了黄曲霉毒素B1的去除，同时避免了二次污染。