Biosorption of Acid Blue 225 from Aqueous Solution by Azolla filiculoides: Kinetic and Equilibrium Studies

Batch studies were conducted for kinetics and equilibrium studies on biosorption of Acid Blue 225 (AB 225) dye from aqueous solution by Azolla filiculoides. The biomass used as adsorbent in this work was initially characterized by SEM and BET. The effect of parameter including adsorbent dose, initial pH, initial concentration and contact time were investigated. Results show that the pH value of 3 is favorable for the biosorption of dye. The dye adsorption efficiency increased with increase in adsorbent dose and contact time. The equilibrium adsorption data were analyzed using three widely applied isotherms: Langmuir,Freundlich and Tempkin. The results revealed that Langmuir isotherm are well fitted on the experimental results. The maximum dye removal efficiency was obtained to be 31.66 at dose adsorbent 2.5 g/L and 19.94 at dose adsorbent 5 g/L. Batch kinetic experiments showed that the adsorption followed pseudo-second-order kinetic model with correlation coefficients greater than 0.997.