Removal of metal ions from aqueous solutions by sorption onto rice bran.

A new sorbent (raw rice bran) was investigated for heavy metal ions removal from aqueous solutions. Rice bran characterisation was carried out in order to identify the functional groups possibly involved in the metal binding. The binding process was studied in terms of binding capacity and metal affinity. The adsorption equilibrium was well described by the Freundlich isotherm model. The negative Gibbs free energy values obtained in this study with rice bran confirm the feasibility of the process and the spontaneous nature of sorption.