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

Abstract

A 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.