Equilibrium, kinetic and thermodynamic studies on the biosorption of Cu(II) onto chestnut shell.

The biosorption of Cu(II) onto chestnut shell, a residue of the food processing industry, in a batch adsorber has been studied. Equilibrium isotherms, kinetic data, and thermodynamic parameters have been evaluated. Equilibrium data agreed well with Langmuir isotherm and Redlich-Peterson isotherm models. The adsorption capacity of chestnut shell for Cu(II) was determined with the Langmuir model and was found to be 12.56 mg g(-1) at 293K. The kinetic data were found to follow the pseudo-second-order model. Intra-particle diffusion is not the sole rate-controlling factor. Gibbs free energy was spontaneous for all interactions, and the adsorption process exhibited exothermic enthalpy values. Chestnut shell was shown to be a promising biosorbent for Cu(II) removal from aqueous solutions.