Selective and competitive removal of dyes from binary and ternary systems in aqueous solutions by pretreated jujube shell (Zizyphus lotus)

Abstract

ABSTRACTIn this work, the selective and competitive adsorption of organic dyes, such as methylene blue (MB), crystal violet (CV), and Congo red (CR), from binary and ternary mixtures in aqueous solutions on pretreated jujube shell (PJS) were evaluated. The characteristics of PJS were studied using FTIR analysis, this characterization suggests the grafting of sulfonate () groups on surface of PJS. The removal efficiency of MB, CV, and CR from a binary and ternary mixture of dyes solutions was examined and optimized toward various parameters: percentage of dye in the mixture, contact time, initial pH of the solution, temperature, and initial solution concentration. The results demonstrated that high effective PJS for adsorption of MB, CV and CR. The data were fitted to linear Langmuir, Freundlich, and Temkin isotherms models. It was found that the sorption of MB, CV, and CR from different mixtures agreed very well with the Langmuir model. The calculated thermodynamic parameters showed that the adsorption of these organic dyes from different mixtures on PJS was spontaneous, endothermic, and increased randomness in the solid/solution interface. The PJS could effectively treat industrial wastewater contaminated by organic dyes.