改性壳聚糖对工业废水重金属离子的吸附处理和修复

Adsorption Treatment and Remediation of Heavy Metal Ions in Industrial Wastewater Using Modified Chitosan

摘要: 随着化工、矿冶、电子等工业的快速发展，含重金属离子废水的排放问题日益严峻。重金属离子难以生物降解，易通过食物链富集，对生态环境和人体健康构成严重威胁。传统物理和化学处理法在成本、效率及二次污染等方面存在诸多局限，开发新型绿色生物吸附材料成为研究热点。壳聚糖作为一种来源丰富、环境友好的天然高分子，其分子链上富含氨基(-NH₂)和羟基(-OH)等活性官能团，可通过静电结合、配位络合等作用高效吸附重金属离子。但天然壳聚糖存在酸稳定性差、机械强度低、官能团种类有限等缺陷，限制了其实际应用。针对上述问题，本文系统综述了壳聚糖的交联改性、接枝改性和复合改性三大策略：交联改性通过戊二醛、乙二醇二缩水甘油醚等交联剂构建三维网状结构，提升材料稳定性和比表面积；接枝改性通过引入硫脲、聚乙烯亚胺等官能团，拓宽适用pH范围并增强吸附容量；复合改性通过与磁性Fe₃O₄纳米粒子、聚丙烯腈、生物炭等功能载体协同组装，实现易分离回收和多功能集成。在此基础上，详细探讨了改性壳聚糖对铜、铬、锌三种典型工业重金属离子的吸附机理与处理优势。综合分析表明，改性壳聚糖凭借吸附容量大、响应速度快、选择性强、可循环再生且无二次污染的综合优势，在工业重金属废水深度处理领域展现出广阔的应用前景，契合循环经济与可持续发展的核心理念。

Abstract: With the rapid development of industries such as chemical engineering, mining and metallurgy, and electronics, the discharge of wastewater containing heavy metal ions has become an increasingly severe problem. Heavy metal ions are difficult to biodegrade and tend to accumulate through the food chain, posing serious threats to the ecological environment and human health. Traditional physical and chemical treatment methods have many limitations regarding cost, efficiency, and secondary pollution; thus, developing novel green biosorbent materials has become a research hotspot. Chitosan, a natural polymer characterized by abundant sources and environmental friendliness, possesses active functional groups such as amino (-NH₂) and hydroxyl (-OH) groups on its molecular chains. It can efficiently adsorb heavy metal ions via electrostatic interactions and coordination complexation. However, natural chitosan suffers from poor acid stability, low mechanical strength, and limited types of functional groups, which restrict its practical application. To address these issues, this paper systematically reviews three major modification strategies for chitosan: cross-linking modification, grafting modification, and composite modification. Cross-linking modification utilizes cross-linkers such as glutaraldehyde and ethylene glycol diglycidyl ether to construct a three-dimensional network structure, thereby enhancing material stability and specific surface area. Grafting modification introduces functional groups like thiourea and polyethyleneimine to broaden the applicable pH range and increase adsorption capacity. Composite modification involves the synergistic assembly with functional carriers such as magnetic Fe₃O₄ nanoparticles, polyacrylonitrile, and biochar to achieve easy separation and multifunctional integration. Furthermore, the paper elaborates on the adsorption mechanisms and treatment advantages of modified chitosan for three typical industrial heavy metal ions: copper, chromium, and zinc. Comprehensive analysis indicates that modified chitosan exhibits broad application prospects in the advanced treatment of industrial heavy metal wastewater due to its comprehensive advantages, including high adsorption capacity, fast response speed, strong selectivity, recyclability, and the absence of secondary pollution. This aligns with the core concepts of a circular economy and sustainable development.