Biosorption of cationic dye from aqueous solutions onto lignocellulosic biomass (Luffa cylindrica) characterization, equilibrium, kinetic and thermodynamic studies
AbstractIn the present study, biomass fiber (Luffa cylindrica) has been successfully used as biosorbent for the removal of a cationic dye namely, methylene blue, from aqueous solution using a batch process. The characterization of the biosorbent was carried out by the infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) The chemical composition has been established by the energy dispersive X Ray spectroscopy (EDS) The effects of various parameters such as the contact time (0 160 min) solution pH (2 10) biosorbent dose (0.5 8 g L 1) particle size, initial MB concentration (20 300 mg L 1) and temperature (20 60 degC) were optimized. The biosorption isotherms were investigated by the Langmuir, Freundlich, Dubinin Radushkevich and Tempkin models. The data were well fitted with the Langmuir model, with a maximum biosorption capacity of 49.46 mg g 1 at 20 degC. The kinetics data were analyzed by the pseudo first order and pseudo second order models. The mass transfer model in terms of interlayer diffusion was applied to examine the mechanisms of the rate controlling step (R2 0.9992 0.9999) The thermodynamic parameters: free energy (DGdeg 5.428 to 3.364 kJ mol 1) enthalpy (DHdeg 20.547 kJ mol 1) and entropy (DSdeg 0.052 kJ mol 1 K 1) were determined over the temperatures range (20 60 degC) The results indicate that Luffa cylindrica could be an interesting biomass of alternative material with respect to more costly adsorbents used nowadays for dye removal.
International Journal of Industrial Chemistry