Study on the competitive adsorption mechanism of bi-component cationic dyes on chitosan biochar
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 adsorp-tion 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 ad-sorption occurs.In the binary system,"synergistic effect"occurs when the dye concentration is low,and"antagonistic effect"occurs when the concentration is high.