镉富集生物质调控制备杂化多孔炭/镉化合物耦合材料及其去除水中新烟碱类农药效能和机理研究

The safe disposal of cadmium-enriched biomass is very important for the development of phytoremediation technology. Pyrolysis technology can transform it into biochar containing cadmium compounds and apply it to the remediation of pesticide polluted water, but its mechanism needs to be further studied. This project plans to regulate the preparation of cadmium compound encapsulated in heteroatom-droped porous biochar with high photocatalytic activity and stability through pyrolysis and modification of cadmium-enriched biomass, and explore the correlation between the preparation conditions and the conversion of cadmium and the physicochemical properties of biochar. Neonicotinoid polluted water in Datong Lake will be selected as the research object. The X-ray absorption fine structure spectra, X-ray photoelectron spectroscopy, Fluorescence emission spectrum and other techniques will be applied. We aim to clarify the distribution behavior and degradation mechanism of neonicotinoid pesticides on surface of the coupling materials from the aspects of photocatalyst structural properties, adsorption characteristics, migration and transformation characteristics of photogenerated carriers and the free radicals, and the transformation path of degradation intermediates. This project will provide theoretical guidance and technical support for resource utilization of heavy metal enriched biomass and remediation of neonicotinoid in water.

安全处置镉富集生物质对植物修复技术的发展至关重要，可通过热解技术将其转化为含镉化合物的生物炭，并资源化应用于修复农药污染水体，但相关机理有待深入研究。为此，本项目拟将镉富集商陆生物质通过热解和改性等途径，调控制备光催化活性高且稳定的杂化多孔生物炭/镉化合物耦合材料，并探究制备条件与镉的转化及生物炭理化性质之间的关联规律。以大通湖受新烟碱类农药污染的水体为对象，利用X射线吸收精细结构光谱、X射线光电子能谱、荧光发射光谱等技术，从耦合材料的结构性质、吸附特性、载流子及自由基的迁移和转化特性、降解中间产物演化规律等角度，从微观上洞悉新烟碱类农药在耦合材料表面的分配行为及降解机理。本项目有望为资源化利用重金属富集生物质和有效修复新烟碱类农药水体提供理论指导和技术支撑。

近年来，以噻虫嗪为代表的新烟碱类农药在水体中频繁检出，危害到了人体健康和生态系统安全。因此，探究如何高效降解水中新烟碱类农药尤为重要。本项目以废弃的商陆生物质为原料优化制备了具备良好催化性能的SNC和CdS@BC复合材料，并对复合材料的形貌、结构和性质等进行了表征；结合杂原子掺杂技术，研究了SNC复合材料活化过硫酸盐对水中噻虫嗪的去除效能及机理；借助ESR和自由基捕获实验来了降解过程中起主要作用的自由基种类；结合了光催化氧化技术和基于过硫酸盐的高级氧化技术，在CdS@BC/PS/Vis反应体系中探究了CdS@BC复合材料对水中噻虫嗪的降解效能和机理；通过活性物质的检测和密度泛函理论(DFT)的计算等分析了噻虫嗪的降解路径，明确其降解机理并对可能的降解路径做出了推测。研究结果将为AOPs去除水中新兴有机污染物的有效催化剂的设计和合成提供理论依据。