不同种类腐殖酸对废水中La(Ⅲ)的吸附研究

Adsorption Studies of La(Ⅲ)in Wastewater by Different Kinds of Humic Acids

为研究不同种类腐殖酸对镧离子的吸附差异性,采用焦磷酸钠法和氢氧化钠法提取出不同种类腐殖酸,并对其元素组成和官能团进行了初步表征;研究温度、pH值、初始浓度、时间对吸附La(Ⅲ)的影响,同时运用准一级、准二级吸附动力学对数据进行拟合,通过Langmuir和Freundlich方程对等温吸附过程进行拟合。结果表明:不同种类腐殖酸的腐殖化程度和芳香度有差异,在酸性条件下不同种类腐殖酸对La(Ⅲ)的吸附量增加,而在碱性条件下除黄腐酸外都降低,温度升高则吸附能力下降,不同种类腐殖酸对La(Ⅲ)的吸附动力学过程更符合准二级动力学吸附方程,等温吸附曲线符合Freundlich模型。

In order to study the adsorption variability of lanthanide ions by different kinds of humic acids,different kinds of humic acids were extracted by sodium pyrophosphate and sodium hydroxide methods,and their elemental compositions and functional groups were preliminarily characterised;the influences of temperature,pH,initial concentration,and time on the adsorption of La(Ⅲ)were investigated,and quasi-primary and quasi-secondary adsorption kinetics were also applied to fit the data,and the adsorption kinetics of the adsorption process were determined by Langmuir and Freundlich equations to fit the isothermal adsorption process.The results showed that the humification degree and the aromaticity of different humic acids were different,the adsorption of La(Ⅲ)by different humic acids increased under acidic condition,while decreased under alkaline condition,except for xanthic acid,and the adsorption capacity decreased with the increase of the temperature,and the adsorption kinetics of La(Ⅲ)by different humic acids was more in line with quasi second-order kinetic adsorption equations,and the isothermal adsorption curves were in line with the Freundlich model.Freundlich model.