Fe_(3)O_(4)/CS/EDTA对水溶液中Cu^(2+)和Ni^(2+)的吸附研究

Study on the Adsorption of Cu^(2+)and Ni^(2+)in Aqueous Solution by Fe_(3)O_(4)/CS/EDTA

分析了自制的Fe_(3)O_(4)/CS/EDTA纳米粒对水溶液中的重金属离子Cu^(2+)和Ni^(2+)的吸附性能和吸附机理。研究了pH值、溶液初始浓度、反应时间等对吸附性能的影响,结合红外、XPS和比表面分析结果确定了参与吸附配位的功能基团及可能发生的络合反应。结果表明:Fe_(3)O_(4)/CS/EDTA对Cu^(2+)和Ni^(2+)的吸附等温线均符合Langmuir模型,对Cu^(2+)的吸附效果要优于Ni^(2+),这可能与Ni^(2+)的离子半径较Cu^(2+)小以及Ni^(2+)与吸附剂形成的金属螯合物的稳定性较Cu^(2+)低有关;Fe_(3)O_(4)/CS/EDTA对Cu^(2+)和Ni^(2+)的吸附机理类似于N·O型螯合剂,并非一般的物理吸附,而是一种以金属离子为中心的吸附螯合。

Heavy metal ions Cu^(2+)and Ni^(2+)in aqueous solution were taken as the object,and the adsorption properties and adsorption mechanism of self-made Fe_(3)O_(4)/CS/EDTA nanoparticles were studied.The effects of pH value,solution initial concentration,reaction time and other factors on adsorption properties were studied.Combined with infrared,XPS and specific surface analysis results,the functional groups involved in the adsorption coordination and the possible complexation reaction were determined.The results show that the adsorption isotherms of Fe_(3)O_(4)/CS/EDTA for Cu^(2+)and Ni^(2+)conform to the Langmuir model,the adsorption effect of Cu^(2+)is better than that of Ni^(2+).This may be related to the fact that ionic radius of Ni^(2+)is smaller than that of Cu^(2+),the stability of metal chelates formed by Ni^(2+)and adsorbent is lower than that of Cu^(2+).The adsorption mechanism of Fe_(3)O_(4)/CS/EDTA on Cu^(2+)and Ni^(2+)is similar to that of N·O chelating agent,and is not general physical adsorption.It is a kind of adsorption chelation with metal ions as the center.