Removal of cadmium (II) from aqueous solution using fermented grape marc as a new adsorbent

Biosorption of cadmium from aqueous solutions using fermented grape marc is investigated in this paper as well as influence of the most important factors, such as: contact time, granulation of biosorbent and the initial concentration of metal ions, is investigated in this paper. The equilibrium sorption of cadmium ions is achieved after 15-20 min., depending on the initial concentration of metal ions. Such a short time needed to achieve the equilibrium indicates that mass sorption is dominate process. Langmuir, Freundlich and Dubinin-Radushkevich isotherm were used to describe the equilibrium sorption process, while Langmuir model was found to be the most conveniente. Maximum of sorption capacity is 20 mg g1. EDS spectrum analysis showed that the process of ion exchange is one of the main sorption mechanism. Minor changes observed in the FTIR spectrum of grape marc after the sorption of Cd(II) ions indicate forming a band between metal ions and partially ionized carboxyl and phenol groups from the biomass. The results of this study confirmed that the fermented grape marc, due to the porous structure and characteristic chemical composition, is good sorption material. nema