Equilibrium and Thermodynamic Studies on Adsorption of Trivalent Chromium by Sericin-alginate Particles Prepared from Bombyx Mori Cocoons

Particles prepared from the blend between sericin and alginate were used as biosorbent of Cr(III) ions form aqueous solution. In order to show how is the Cr(III) distribution between the liquid phase and the solid phase at the equilibrium, biosorption isotherms were obtained at four different temperatures (20, 30, 40, 60 °C). The isotherm models of Langmuir, Freundlich and Dubinin–Radushkevich were used to test the equilibrium biosorption data. Better fittings were obtained for both Langmuir and Dubinin–Radushkevich models. Additionally, the thermodynamic parameters enthalpy change, entropy change, and Gibbs free energy change were calculated and the biosorption process was found to be exothermic and spontaneous. The results shown that sericin-alginate particles are a promising biosorbent material for the efficient removal of Cr(III).