Removal of Reactive Orange 4 from Aqueous Solution by Waste Eichhornia crassipes Biomass

Biosorption of Reactive Orange 4 dye, from an aqueous solution was evaluated by Eichhornia crassipes in a batch system. The influence of pH (1-6), temperature (20-30(circle)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(circle)C and at the initial dye concentration of 120 mg/L. Batch biosorption kinetics was studied with different initial dye concentrations and rate of biosorption was determined using the 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 Orange 4 when compared to pseudo first order kinetic model. The intra particle diffusion coefficient (Ki) and effective diffusion coefficient (Di) values obtained for the sorption of Reactive Orange 4 using E. crassipes was found to be increased with increase in initial dye concentrations.