Adsorption equilibrium and kinetic studies of methylene blue on banana peel based activated carbons

Abstract

Activated carbon is the most commonly used adsorbent for wastewater treatment and water purifications. The main characteristics of activated carbon are its high surface area and high adsorption capacity with certain adsorbates. In this work, activated carbons were synthesized using banana peel wastes. The samples were activated chemically using zinc chloride as the activating agent. These samples were then activated at 600 °C in nitrogen flow respectively. The activated carbons were characterized by Scanning Electron Microscopy (SEM) and nitrogen adsorption at 77 K. Results indicated that activation processes improved the uptake of methylene blue (MB) with respect to adsorption results obtained for raw precursors. The adsorption equilibrium and kinetic studies of MB adsorption were then conducted. Experimental results showed that the equilibrium data can be represented well by the Dubinin Raduskevich model. Meanwhile, the adsorption kinetic data followed the pseudo second order model. Overall, activated carbons obtained from banana peel wastes showed good performance for the removal of MB dyes. The activated carbon prepared from banana peel wastes exhibits good surface characteristics and porosity properties. This indicates that banana peel can be one of a promising precursor for the production of commercal activated carbon.