壳聚糖修饰的多孔地质聚合物微球固定化漆酶体系的构建及其净化水中有机污染物的研究

Water contamination with organic chemicals is one of the most serious problems afflicting people throughout the world, innovation of materials with eco-friendliness is important for a greener environment. Here, a novel porous geopolymeric microsphere is proposed as a carrier to immobilize laccase. The microsphere will be prepared by a suspension and solidification method using metakaolin and sodium silicate as the main raw materials and pore-forming agents as the additives. It contains the advantages of being environmentally friendly, low cost, safe, stable, easy-handled and can be used for continuous treatment of waste water. The production of the porous microsphere is going to be optimized by adjusting the reaction conditions. The structure of the porous microsphere is analyzed by various analyzer. The immobilization of laccase onto the porous geopolymeric microspheres by a self-assembled approach would be enhanced by grafting chitosan. The enzymatic activity, stability and reusability would be investigated. The effects of different conditions on the removal efficiency of organic pollutants (dye, dichlorophenol and antibiotics) in water will be also investigated. The removal mechanism will also be investigated. Safety, high efficiency and continuous removal of organic pollutants from water is the project's ultimate goal. The project provides the new way for a wide application of geopolymer and laccase, the basis of data and technology reference for related industries and some scientific guidance for ecological restoration and reconstruction in water pollution control during China's sustainable development.

面对日益严重的有机废水对环境造成危害的问题，本项目通过构建壳聚糖修饰的多孔地质聚合物微球固定化漆酶体系，利用地质聚合物稳定的多孔结构、漆酶快速的氧化还原能力，壳聚糖丰富的有机官能团，实现对有机废水的快速有效处理。以廉价的偏高岭土为原料，工业水玻璃作为碱激发剂，加入造孔剂，采用反相悬浮聚合法制备多孔地质聚合物微球，以静电自组装的方式对多孔地质聚合物微球进行壳聚糖修饰，作为漆酶载体，该载体具有制备简单、绿色环保、低成本、安全有效、易于连续操作、可循环利用和稳定性好的优势。通过对配方的调节和反应条件的改变，对产品的结构和性能进行分析，实现多孔载体的可控制备，获得酶学性质与载酶调控机制，分别探索其在水溶液中对染料、氯酚和抗生素等有机污染物的净化效果和协同净化机理，为地质聚合物和漆酶更广泛的应用提供新途径，为工业化应用提供基础数据，为我国可持续发展中的水污染综合治理提供科学指导。

水污染严重影响人类社会的可持续性发展，生物酶法处理废水是当前研究的热点之一。漆酶是一种多酚氧化酶，在温和的条件下可氧化降解多种有机污染物如染料、氯酚和抗生素等，但是自由酶的不稳定性和难回收性极大的限制了其实际应用，因此酶的固定化技术显得尤为重要。该项目以壳聚糖修饰的多孔地聚物微球为漆酶载体，研究了载酶规律，考察了固定化漆酶对水中多种有机污染物的净化效果和机制。首先进行了悬浮固化法可控制备多孔地聚物微球技术的基础研究，制备了偏高岭土基地聚物微球，矿渣基地聚物微球，考察了不同制备工艺条件对微球结构和性能的影响，分析了微球对不同种类染料的吸附机理和去除性能，探索了吸附动力学、热力学和动态穿透模型，实现了地聚物微球对水体中阳离子型染料的选择性去除。进一步以氨基酸和油酸作为造孔剂，以偏高岭土基多孔地聚物微球作为固定化漆酶载体，研究了最适载酶条件、载酶规律和过程强化措施，分别实现了介体和漆酶、铜和漆酶的双固定化，进一步提升了对污染物的去除性能并避免了二次污染物，对水中结晶紫、刚果红、四环素的去除率均可以达到94%以上。利用静电作用对地聚物微球进行壳聚糖修饰，有效提升了固定化酶的稳定性，基于吸附-降解动力学规律分析，阐述了吸附-酶催化降解协同净化机理。通过本项目的研究，可为新型固定化酶体系的建立并应用于水中多种有机污染物的去除提供理论依据和技术支持。