Removal of hexavalent chromium from aqueous solution by a novel biosorbent Caryota urens seeds: equilibrium and kinetic studies

A novel biosorbent Caryota urens seeds (CUS) was investigated for the technical feasibility for the biosorption of hexavalent chromium from aqueous solution. The biosorbent was characterized by SEM, FT-IR spectral, and EDS analysis. Effects of biosorbent size, biosorbent dosage, Cr(VI) concentration, pH, and contact time on the biosorption of hexavalent chromium were investigated. Both the Langmuir and Freundlich isotherms were suitable for describing the biosorption of Cr(VI) onto CUS. Application of the Langmuir isotherm model to the biosorption system yielded a maximum biosorption capacity of 52.63 mg/g at an equilibrium pH value of 2 and 303 K. Kinetic data were best fitted with the pseudo-second-order kinetic model. The results indicate that the CUS can be effective biosorbent for the removal of Cr(VI) from aqueous solution.