Biosorption of reactive blue 19 dye using Lemna minor: Equilibrium, kinetic and thermodynamic studies

Abstract

Dyes are the main pollutants existing in wastewater of textile industries. This paper presents the sorption studies of Reactive Blue 19 (RB19) dye by the Lemna minor. The effect of different parameters like pH, adsorbent dose, contact time, temperature and initial dye concentrations were investigated. The biosorption data have been analysed using Langmuir, Freundlich and Temkin isotherms. The equilibrium uptake capacity was increase from 7.12 mg/g to 46.51 mg/g, when increasing the dye concentration from 25 mg/L to 200 mg/L. The equilibrium data were best represented by the Langmuir isotherm. The adsorption kinetics were found to follow the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔGo, ΔHo and ΔSo have also been evaluated and sorption process was feasible, spontaneous and exothermic in nature. The results indicate that L. minor is a suitable adsorbent for the adsorption of textile dyes.