双组分阳离子染料在壳聚糖生物炭上的竞争吸附机理研究

Study on the competitive adsorption mechanism of bi-component cationic dyes on chitosan biochar

研究了壳聚糖生物炭(CB)对水溶液中阳离子染料龙胆紫(GV)和孔雀石绿(MG)的吸附机理。通过吸附等温线对一元体系和二元体系中阳离子染料GV和MG在生物炭上吸附行为进行分析。一元体系中,吸附平衡实验研究发现,Langmuir模型可对CB吸附GV和MG的吸附行为进行描述,表明其为单层吸附。而二元体系中,extended-Langmuir模型和Langmuir-Freundlich模型可对CB吸附GV和MG的吸附行为进行描述,表明GV和MG之间存在相互作用,也就是说吸附位点上染料分子的吸附取决于其他吸附位点上染料分子的存在情况,发生了多层吸附现象。二元体系中,染料浓度较低时发生“协同作用”,浓度较高时发生“拮抗作用”。

This work mainly studied the adsorption mechanism of chitosan biochar(CB)on cationic dyes gentian violet(GV)and malachite green(MG)in aqueous solution.The adsorption behavior of cationic dyes GV and MG on biochar was analyzed by adsorption isotherm.In the single system,the adsorption equilibrium experiment found that the Langmuir model can describe the adsorption behavior of CB adsorption GV and MG,indicating that it is mono-layer adsorption.In the binary system,the extended-Langmuir model and Langmuir-Freundlich model can describe the adsorption behavior of CB adsorbing GV and MG,indicating that there is an interaction between GV and MG,that is,the adsorption of dye molecules on the adsorption site depends on the presence of dye molecules on other adsorption sites,and multi-layer adsorption occurs.In the binary system,“synergistic effect”occurs when the dye concentration is low,and“antagonistic effect”occurs when the concentration is high.