Utilization of durian (Durio zibethinus Murray) peel as low cost sorbent for the removal of acid dye from aqueous solutions

In this paper, durian peel (DP), an agricultural waste, was evaluated for its ability to remove acid dye from aqueous solutions. Adsorption equilibrium and kinetics of acid green 25 (AG25) from aqueous solutions at various initial dye concentrations (50–500 mg/L), pH (2–10), and temperature (30–50 °C) on DP were studied in a batch mode operation. Equilibrium isotherms were analyzed by Langmuir and Freundlich isotherm models. The equilibrium data were best represented by Langmuir isotherm model with maximum monolayer adsorption capacity of 63.29 mg/g at 30 °C. Kinetics analyses were conducted using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. It was found that the adsorption kinetics of AG25 on DP obeyed pseudo-second-order sorption kinetics. The results indicate the potential of DP as sorbent for the removal of acid dye from aqueous solution.