Potential use of activated carbon derived from Persea species under alkaline conditions for removing cationic dye from wastewaters

Abstract

The use of Persea americana has been studied as an alternative source of activated carbon for the removal of dyes from wastewater. Chemical activation using phosphoric acid was employed for the preparation of the activated carbon (C-PAN). The BET surface area and the total pore volumes were found to be 1593 m²/g and 1.053 cm³/g, respectively. This study investigates the effect of some parameters like, dye concentration, adsorbent dose, contact time and pH for the best comprehension of the adsorption manner. Adsorption kinetic follows pseudo-second order kinetic model. Langmuir and Freundlich isotherms models were used to analyze the adsorption equilibrium data and the best fits to the experimental data were provided by Langmuir model. Maximum adsorption capacity is equal to 400 mg/g of Basic Yellow 28 onto the activated carbon derived from Persea americana. Thermodynamic parameters, such as standard Gibbs free energy (ΔG⁰), standard enthalpy (ΔH⁰) and standard entropy (ΔS⁰) has been calculated. The adsorption process was found to be spontaneous and exothermic process.

This study shows that the activated carbon provided from Persea americana can be an alternative to the commercially available adsorbents for dyes removal from liquid solutions.