Adsorption of Methylene Blue from aqueous solution using Senegal River Typha australis

Abstract

In this work, batch adsorption experiments were carried out for the removal of Methylene Blue (MB) from aqueous solutions using Typha australis leaf as a low cost adsorbent. The effects of some variables governing the efficiency of the process such as adsorbent mass, pH, ionic strength, contact time and temperature were investigated. The adsorption kinetic data were analyzed using the Pseudo First Order (PFO) and Pseudo Second Order (PSO) models. The experimental equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The results show that the PSO model is the best for describing the adsorption of MB by Typha australis for all initial MB concentrations. The equilibrium data fitted well with the Langmuir model with the monolayer adsorption capacity for MB-Typha australis leaf system was of 103.12 mg g-1. The values of activation parameters such as free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were also determined as - 4.44 kJ mol−1, 55.13 kJ mol−1 and 203.21 J mol−1 K−1, respectively. The thermodynamics parameters of MB-Typha australis system indicate spontaneous and endothermic process. These results indicate that the Typha australis leaf can be feasibly employed for the eradication of MB from aqueous solution.