Biosorption of Malachite Green from Aqueous Solutions onto Polylactide/Spent Brewery Grains Films: Kinetic and Equilibrium Studies

Abstract

Batch experiments were conducted to study the biosorption of Malachite Green (MG) onto polylactide (PLA)/spent brewery grains (SBGs) films. Films were prepared by solvent-casting method using dichloromethane. Effects of contact time, pH, salt concentration, and optimal experimental condition was evaluated. At pH 6.89 and low salt concentration, Malachite Green was removed effectively. The isotherm data fitted the Freundlich model with 0.969 R2 value and 0.738 slope implying chemisorptions process. The biosorption process followed pseudo-second order kinetics with calculated adsorption capacity at equilibrium (qe) of 0.572 mg/g at 23 °C. The investigation showed that PLA/SBGs films are effective in dye removal from textile, paper and leather industries effluents.