Study on anionic dye toxicity reduction from simulated media by MnO2/agro-biomass based-AC composite adsorbent

Abstract

In order to reduce the consequences of increased by-products generated by demand for plants essential oil extraction factories, it is important transforming such waste disposal into useful materials. Herein, efficient adsorbent from residues of Eucalyptus camaldulensis leaves (ECL-AC) supported αMnO2 was prepared by the redox reaction between Mn2+ and Mn7+ at approximatively neutral pH and ECL-AC to increase their interactions contributing to the enhanced adsorptive capacity for Helianthine from aqueous media. The by-product was simultaneously activated by impregnation in Potassium permanganate solution as oxidizing agent followed by heating in tubular furnace under controlled atmosphere, resulting in α-MnO2-AC adsorbent. Prior to removal tests, the prepared AC- MnO2 sample was characterized for functional groups (IRFT) and pores structure by evaluation the iodine number (IN) and methylene blue index (MBI). Parameters affecting Helianthine uptake such as equilibrium time, adsorbent dose, solution pH and temperature were also studied. Well known adsorption isotherm models namely, Langmuir, Freundlich and Temkin were used for data analysis and better described by Langmuir model with a maximum uptake of 64.71 mg/g at pH 2.08. The surface area estimation indicates that AC-MnO2 better described by Langmuir model. The surface area estimation indicates that MnO2-AC is microporous/mesoporous material. Calculated thermodynamic parameters showed that the adsorption of Helianthine dye onto MnO2-AC is a spontaneous and exothermic process. Results indicate that this doped biomass based-activated carbon can be used successfully as an alternative low-cost adsorbent in the removal of Helianthine from industrial effluents.