Removal of Eriochrome black-T from wastewater by utilizing the commercial DF-120 anion exchange membrane

Abstract

This work describes the batch adsorption of Eriochrome black-T (EBT) an anionic dye onto the DF-120 commercial anion exchange membrane (AEM) from wastewater at 25 °C. The effect membrane dosage, temperature, ionic strength, contact time, pH and initail concentration on EBT adsorption was illustrated. Adsorption capacity (q_e) was enhanced from 7.32 to 12.71, 1.77 to 12.71, 6.71 to 12.71, and 16.16 to 17.39 mg/g with membrane dosage (mass), initial concentration, contact time, and ionic strength respectively while decreased from 12.71 to 3.77 and 12.71 to 3.65 mg/g with temperature and pH of medium respectively. Adsorption of EBT was subjected to various adsorption isotherms including Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) models. It was noticed that EBT adsorption obeyed Freundlich isotherm because the value of correlation coefficient (R² = 0.991) was close to unity. Several kinetics models were utilized to demonstrate EBT adsorption. Results showed that EBT adsorption fitted to pseudo-second order (PSO) model because the value of correlation coefficient (R² = 0.997) was close to unity. Adsorption thermodynamics study represented that EBT adsorption onto the DF-120 commercial AEM was an exothermic process (ΔH°= −79.78 KJ/mol). In addition, the regeneration of DF-120 commercial AEM was also studied.