Effect of Biosorption Parameters Kinetics Isotherm and Thermodynamics for Acid Green Dye Biosorption from Aqueous Solution by Brewery Waste

Biosorption of Acid Green (AG 25) was investigated using Spent Brewery Grains (SBG) a brewing industry waste in abatch system with respect to initial pH, temperature, initial dye concentration, biosorbent dosage, and contact time. Thebiomass exhibited the highest dye uptake capacity at 303 K, initial pH value of 3, the initial dye concentration of90mg/L, biosorbent dosage of 0.2 g and contact time of 75 min. The extent of dye removal increased with increase intime, biosorbent dosage and decreased with increase in temperature. The equilibrium sorption capacity of the biomassincreased on increasing the initial dye concentration up to 90 mg/L and then started decreasing in the studiedconcentration up to 300 mg/L. The experimental result has shown that the acidic pH favours the biosorption. Langmuirand Freundlich adsorption model is used for the mathematical description of the biosorption equilibrium and isothermconstants are evaluated. Equilibrium data fitted very well to the Langmuir model. The pseudo first- and second-orderkinetic models were also applied to the experimental data. The results indicated that the dye uptake process followed thepseudo second-order rate expression and biosorption rate constants increased with increasing concentration.