Biosorption of eosin yellow dye from aqueous solution using sugarcane bagasse: Equillibrium, kinetics and thermodynamics

Abstract The objective of the present research is to study the biosorption of Eosin yellow using Sugarcane Bagasse. Batch operations were carried out to observe the effect of various experimental parameters such as Agitation time (5–120 min), pH (2–9), Biosorbent dosage (1–4 g/L), Biosorbent size (100, 120, 150 µm) Initial concentration (25–150 mg/L) and Temperature (283–323 K). Study of biosorption kinetics, isotherms was carried out and best fitting models for rate kinetics and isotherms were obtained. The kinetic experimental data was analyzed using two kinetic equation-pseudo first order equation and pseudo second order equation. The Langmuir, Freundlich, Redlich-peter son, Temkin and Harkin-Jura isotherms were used to fit the equilibrium data. From the results, the equilibrium agitation time for Eosin yellow dye was 90 min and pH value of 6. The uptake was decreased, and percentage removal was increased with an increase in the biosorbent dosage from 0.05–0.25 g and for biosorbent sizes from 100 to 150 µm. The % biosorption of Eosin yellow was increased with an increase in the temperature. The dye removal data of Eosin yellow follows the Langmuir model with the best fit and dye uptake obtained is 58.47 mg/g. The biosorption of eosin yellow on Sugarcane Bagasse can be better described with pseudo second order kinetics. The study reveals the endothermic nature of biosorption as ΔH is positive, irreversible nature of biosorption, as ΔS is positive and spontaneity of biosorption as indicated by negative ΔG for Eosin yellow dye. The results indicated that sugarcane bagasse can be used as a good low-cost alternative biosorbent for treatment of effluents containing eosin yellow.