Musanga cecropioides Sawdust as an Adsorbent for the Removal of Methylene Blue from Aqueous Solution

Abstract

Adsorption is an established method of removing dyes and other pollutants from aqueous solution. The success of adsorption depends on the nature of adsorbent. In this work, saw dust from musanga cecropioides is used for the removal of methylene dye from aqueous solution. Effect of contact time, adsorbent dosage, temperature and concentration of the dye were investigated. The results indicated that at various adsorption dosage, concentrations, contact time and temperature, the equilibrium amount of dye adsorbed, qe (mg/g) ranged from 1.86 to 5.32, 3.44 to 4.55, 3.73 to 4.58 and from 0.89 to 3.88 respectively. The kinetic of the adsorption was best described by pseudo second order kinetics. The adsorption of the dye on the surface of the wood saw dust was exothermic, spontaneous and favours Langmuir and Temkin isotherm. Based on the observed trend in the variation of extent of adsorption with temperature and calculated values of free energy changes, the adsorption follows both physical and chemical adsorption mechanism. However, physisorption dominated the adsorption at lower temperature. The use of saw dust from musanga cecropioides wood is hereby recommended for commercial applications.