• 关键词：磁性壳聚糖  凝胶微球  多元重金属  竞争吸附  固定床动态吸附

• 基金项目：国家自然科学基金（No.41772264）

• 蒲生彦
• 1. 成都理工大学, 地质灾害防治与地质环境保护国家重点实验室, 成都 610059;2. 成都理工大学环境学院, 国家环境保护水土污染协同控制与联合修复重点实验室, 成都 610059

• 肖雨婷
• 成都理工大学, 地质灾害防治与地质环境保护国家重点实验室, 成都 610059

• 马慧
• 1. 成都理工大学, 地质灾害防治与地质环境保护国家重点实验室, 成都 610059;2. 丹麦哥本哈根大学, 植物与环境科学系, 丹麦 401871

• 王可心
• 成都理工大学, 地质灾害防治与地质环境保护国家重点实验室, 成都 610059

• 摘要：以壳聚糖为代表的天然生物质自身含有大量活性基团能选择性吸附重金属离子，为重金属废水的高效经济处理提供了可能.本实验以壳聚糖为基材，采用原位共沉淀法和乙二醇二缩水甘油醚（EGDE）交联法共同作用制得CS-EGDE/Fe₃O₄凝胶微球吸附剂，通过电子扫描显微镜（SEM）、透射电镜（TEM）、X射线能谱（EDS）、傅里叶红外光谱（FTIR）、饱和磁强分析（VSM）对样品进行了充分表征.通过静态吸附批实验及模拟固定床动态吸附实验，较系统的考察了凝胶微球在不同初始pH、接触时间和初始浓度下对多元重金属Pb（Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）的吸附性能.结果表明：①CS-EGDE/Fe₃O₄凝胶微球内部孔隙发达，具有良好的超顺磁性；②吸附剂能够快速与重金属离子发生螯合反应，主要作用基团为-NH₃和-OH，且对重金属离子吸附符合准二级动力学，吸附过程可用Langmuir等温吸附方程描述，为单层化学吸附；③在多元吸附体系中发生拮抗作用，重金属竞争吸附顺序为Pb（Ⅱ） > Cu（Ⅱ） > Zn（Ⅱ），主要是3种离子共价指数的差异导致了这一结果；④固定床在多元重金属模拟废水处理中表现出良好的去除效能，对Pb（Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）的饱和吸附时间分别为13、8、2 h.研究显示，CS-EGDE/Fe₃O₄凝胶微球对水中重金属离子具有良好的吸附性能，有望为重金属废水处理提供一种新的研究思路和技术路线.

• Abstract：The natural biomass represented by chitosan contains a large number of active groups to selectively adsorb heavy metal ions, which provides a possibility for efficient and economical treatment of heavy metal wastewater. The adsorbent was prepared by a combination of in situ-coprecipitation and ethylene glycol diglycidyl ether crosslinking using chitosan as raw material. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometry (VSM). The static adsorption experiments and simulated fixed bed dynamic adsorption experiments were carried out to investigate the adsorption behavior of Pb(Ⅱ), Cu(Ⅱ) and Zn(Ⅱ) by the gel microspheres under different initial pH, contact time and initial concentrations. The results show that:①CS-EGDE/Fe₃O₄ gel microsphere has well-developed internal porosity and good magnetic properties;②The adsorbent can rapidly chelate with heavy metal ions. The main groups are -NH₃ and -OH, and the adsorption of heavy metal ions conforms to quasi-secondary kinetics. The adsorption process can be described by Langmuir isotherm adsorption equation, which is single-layer chemical adsorption;③Antagonism occurred in the ternary adsorption system, and the competitive adsorption order of heavy metals was Pb(Ⅱ) > Cu(Ⅱ) > Zn(Ⅱ), mainly owing to the difference in the covalent index of the three ions;④The fixed bed shows good adsorption performance in the treatment of ternary heavy metal simulated wastewater. The adsorption saturation times of heavy metal Pb(Ⅱ), Cu(Ⅱ), and Zn(Ⅱ) were 13, 8, and 2 h, respectively. The study indicates that CS-EGDE/Fe₃O₄ gel microsphere has good adsorption performance for heavy metals and it is expected to provide a new technical route for heavy metal wastewater treatment.

• Key words：magnetic chitosan  gel microspheres  multi-component heavy metals  competitive adsorption  fixed bed dynamic adsorption

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