Optimization of Batch Adsorption Study Parameters of Acid Dyes onto Spent Brewery Grains

Abstract

The exploration of economical and nature friendly adsorbents for dye elimination from effluent is a promising area of research, driven by the need for sustainable and economically viable solutions. This work deals with the adsorption features of Acid Blue 25 (AB25) and Acid Green 25 (AG25) dyes from aqueous solutions using spent brewery grains (SBG). After brewing process, the obtained residue consists of spent grains. Optimum conditions for AB25 & AG25 removal were found to be at pH 2, adsorbent dosage as 0.8 and 1 g/L of solution respectively and equilibrium time was found to be 60 mins. In order to adjudicate the adsorption process, analysis was carried out with kinetic and isothermal two parameter and three parameter models. The results were discovered to fit most with the pseudo-second-order (R2 = 0.990) for the kinetics and the Langmuir isotherm (R2 = 0.993) for the adsorption isotherms. The isotherms and kinetics verified that SBG had a high value of adsorption capacity. Experiment results pointed out SBG is one of the best adsorbent that eco-friendly, economical, readily accessible, and efficient on the removal of AB25 and AG25 dyes from aqueous solution.