Equilibrium and Kinetic Modeling on Biosorption of Reactive Red 2 Using Tamarindus indica Fruit Hulls

Abstract

Biosorption of Reactive Red 2 dye, from an aqueous solution was evaluated using Tamarindus indica fruit hulls in a batch system. The influence of pH (1-6), temperature (20-30°C) and initial dye concentration (20 to 120 mg/L) on the biosorption process was studied. Maximum biosorption was observed at initial pH of 2.0, temperature of 30°C and at the initial dye concentration of 120 mg/L. Equilibrium data were analysed for Langmuir, Freundlich and generalized isotherm model. The equilibrium data were found to fit very well with Freundlich isotherm model when compared to all other isotherm models studied in the present investigation. Batch biosorption kinetics was studied with different initial dye concentrations and rate of biosorption was determined using pseudo first and pseudo second order rate equations. From the result it was observed that pseudo second order rate expression fit the experimental data well for Reactive Red 2 when compared to a pseudo first order kinetic model.