Equilibrium and Kinetic Studies on the Removal of Acid Green 27 Dye Using Positively Charged Biosorbent Ocimum tenuiflorum

摘要

Biosorption is a technique that can be used for the removal of pollutants from wastewater. In this present study, the biosorption ability of Ocimum tenuiflorum biomass towards acid green 27 dye was discussed. The influence of biosorbent dosage (0.2 to 1.0 g/L), pH (1 to 6) and initial dye concentration (30 to 110 mg/L) on the biosorption of dye was studied. With the initial dye concentration of 70 mg/L and pH value of 6, the equilibrium dye uptake capacity was observed to be more at 0.2 g/L of biosorbent dosage when compared to all other biosorbent dosage studied in the present investigation. The biosorbent dosage of 0.2 g/L at 70 mg/L initial dye concentration, the equilibrium dye uptake capacity was observed to be more at pH value of 2 when compared to all other pH studied in the present investigation. In this present study, the maximum uptake capacity of acid green 27 dye was observed as 88.10 mg/g using O. tenuiflorum at 110 mg/L initial dye concentration. The scanning electron microscopy was used to study the surface morphology of the Ocimum tenuiflorum. The equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherm model. The equilibrium data was found to be followed very well with the Freundlich adsorption isotherm at 30 °C. The kinetic data was analyzed using Pseudo-first and Pseudo-second order rate equations. The Pseudo-second order rate expression fitted the experimental data well. Intraparticle diffusion parameter (K.) and diffusion coefficient (D.) was investigated for the biosorption mechanism. The functional group present in the biomass was identified by FTIR spectroscopy.