Vermicompost as a potential adsorbent for the adsorption of methylene blue dye from aqueous solutions

Abstract

Vermicompost (VC) as a low cost and waste-derived material was used as an adsorbent to remove textile dye effluents from the wastewater. Methylene blue (MB) was selected as a representative of dye effluents and its adsorption to VC was investigated. The effect of parameters such as pH, adsorption time, and the initial concentration of MB were determined via lab-scale batch experiments. The highest adsorption capacity of VC was reached when the pH of the solution was 4. The equilibrium was maintained after 90 minutes of operation since the removal percentage of MB was stabilized at 99%. The pseudo-second-order kinetic model described the most appropriate adsorption kinetic behavior. Both Langmuir (R2=0.9891) and Freundlich isotherms (R2=0.9895) fitted very well to the experimental data. Based on these results, vermicompost can be evaluated as an alternative adsorbent for the removal of dye effluents.