Removal of acid black 1 by Acacia Concinna; adsorption kinetics, isotherm and thermodynamic study

Abstract

In the present research, batch adsorption of anionic dye such as Acid Black 1 (AB1) in aqueous solution onto biosorbent Acacia concinna was investigated at room temperature. The effect of various physico-chemical parameters such as contact time, adsorbent dosage, initial dye concentration and temperature on the percentage removal of dye were investigated. Adsorption kinetics was investigated using linear and nonlinear form of pseudo first-order and pseudo-second-order kinetic models but experimental data for adsorption of AB1 dye in aqueous mixture onto biosorbent Acacia concinna was fitted well to pseudo-second order model with maximum value of regression coefficient (0.9995). Linear and nonlinear forms of Langmuir, Freundlich, Tempkin, and Dubinin– Radushkevich (D–R) were used to reveal experimental data but experimental data for adsorption of AB1 dye in aqueous mixture onto biosorbent Acacia concinna fitted well to the Langmuir isotherm model with adsorption capacity 3.21✕10-4 Adsorption thermodynamic study showed that adsorption of AB1 dye onto adsorbent Acacia concinna was endothermic and spontaneous process. This study revealed that biosorbent Acacia concinna was good biosorbent for removal of dyes from aqueous solution.