尖晶石铁氧体去除水中锑的吸附行为和作用机理研究

Study on Adsorption Behavior and Mechanism of Spinel Ferrites for Antimony Removal from Water

水体锑污染引发的健康问题备受关注。本文通过溶剂热法制备了四种不同金属位点的尖晶石铁氧体MFe_(2)O_(4)(M=Mn、Zn、Cu和Ni),通过批实验考察了p H、吸附时间、初始浓度对MFe_(2)O_(4)去除Sb(Ⅲ)的影响规律,分析比较MFe_(2)O_(4)对Sb(Ⅲ)吸附性能和吸附行为的差异性,利用光谱学分析揭示其除锑机理。结果表明,MFe_(2)O_(4)对Sb(Ⅲ)的去除与p H成正比,其吸附行为符合准二级动力学模型和Langmuir等温吸附模型,Sb(Ⅲ)的去除是以化学吸附为主导的单层均匀吸附,Mn Fe_(2)O_(4)、Zn Fe_(2)O_(4)、Cu Fe_(2)O_(4)和Ni Fe_(2)O_(4)的最大Sb(Ⅲ)吸附容量分别为196.94、164.30、180.72和145.69 mg/g。光谱学分析结果表明,Sb(Ⅲ)主要通过与Fe-OH和Fe-O作用而被固定,且在吸附过程中MFe_(2)O_(4)的微观形貌发生变化但晶体结构没有发生变化。四种MFe_(2)O_(4)吸附Sb(Ⅲ)的吸附行为和去除机理具有相似性,但Mn Fe_(2)O_(4)的吸附性能最为优越。这些发现有助于尖晶石铁氧体在锑污染上的修复应用。

In recent years,health risks caused by antimony(Sb)contamination in water environment have attracted considerable attention.In this study,four spinel ferrites MFe_(2)O_(4)(M=Mn,Zn,Cu,and Ni)with different metal sites were synthesized though the solvothermal method,and the effects of pH,adsorption time and initial concentration on Sb(Ⅲ)removal by four MFe_(2)O_(4) were investigated by bath experiments.The differences in the adsorption properties and behaviors of four MFe_(2)O_(4) for Sb(Ⅲ)were analyzed and compared,and the corresponding Sb(Ⅲ)removal mechanism was revealed using spectroscopic analysis.The results showed that the effect of Sb(Ⅲ)removal by MFe_(2)O_(4) was proportional to solution pH,and the adsorption behaviors followed the pseudo-second-order model and Langmuir model,indicating that chemical adsorption with a homogeneous monolayer was the dominant driving force for Sb(Ⅲ)removal.The maximum Sb(Ⅲ)adsorption capacities of MnFe_(2)O_(4),ZnFe_(2)O_(4),CuFe_(2)O_(4) and NiFe_(2)O_(4) were 196.94,164.30,180.72 and 145.69 mg/g,respectively.Results of spectroscopic analyses indicated that Sb(Ⅲ)was immobilized mainly through the interactions with Fe-OH and Fe-O groups,with the obvious change in the microstructure and insignificant change in crystal structure of MFe_(2)O_(4) during Sb(Ⅲ)adsorption process.Although the adsorption behavior and removal mechanism of Sb(Ⅲ)by the four MFe_(2)O_(4) samples were found to be similar,MnFe_(2)O_(4) exhibited the optimal adsorption performance.These findings provide valuable insights into the application of spinel ferrites in the remediation of Sb-contaminated water.