Calcium alginate entrapped Eupatorium adenophorum Sprengel stems powder for Chromium(VI) biosorption in aqueous medium

Abstract

ABSTRACTA novel biosorbent, Eupatorium adenophorum Sprengel was used for biosorption of chromium (VI) from aqueous solutions. Optimum pH, biomass concentration and contact time were estimated at 2.0, 1.0 g/L and 60 min respectively. Data obtained from batch studies confirmed well to the Langmuir model. It was found that the overall biosorption process was best described by pseudo second-order kinetics. The results demonstrated that intraparticle diffusion is not the sole rate-controlling step for the whole sorption process. In binary mixtures, biosorption efficiency of Cr(VI) was not significantly affected by the presence of ions up to 50 mg/L. Thermodynamic study showed that Cr(VI) biosorption on Eupatorium adenophorum-alginate beads was spontaneous, exothermic and physisorption in nature. Cr(VI) ions were recovered effectively from Eupatorium adenophorum-alginate beads using 0.5 M HNO3 solution.