Eco-friendly removal of methylene blue from aqueous medium using low cost sawdust-biochar adsorbent

Abstract

This study reports on the facile synthesis and viability of sawdust-derived-biochar adsorbent for the effective removal of methylene blue dye pollutant from aqueous medium. The crystallinity, morphology and surface functional groups of the synthesised materials were determined using XRD, SEM and FTIR characterisation techniques. The adsorption efficiency of sawdust biochar was investigated by observing the removal of methylene blue dye (MB) from an aqueous system while varying process parameters like the adsorbent loading and initial concentration. Results showed that the sawdust biochar achieved remarkable removal of 98.7 % MB in 90 minutes and a complete removal after 120 minutes. The adsorption kinetics were best described by the pseudo-first-order kinetics model and had a R2 value higher than 0.97. Additionally, the Langmuir adsorption isotherm model, which points to monolayer adsorption, fit the results best and showed the material to have an adsorption capacity of 151.3 mg/g. Finally, the results obtained from this study depicts the efficiency of sawdust biochar in the removal of organic dye and points a way forward in achieving zero pollution and a toxic-free environment.