Yeast and magnetite bionanocomposite for the removal of Cr(VI) and Zn(II) in aqueous medium: synthesis, characterization and adsorption

Abstract

Studies on biosorption have increased due to their great relevance in environmental remediation. The biosorption process aims to use as biomass/biosorbent a material that is effective for the sorption of contaminants, considered viable due to its low cost, abundance, efficiency, and the possibility to reuse organic/biological waste for the remediation of contaminated aquatic environments. Therefore, by knowing the importance of water, free of toxic substances, a biosorbent based on yeast residues (YB, Saccharomyces cerevisiae) from sugar-alcohol industries and a composite prepared from YB and ferromagnetic nanoparticles (Fe3O4) is proposed. These materials will be synthesized by the co-precipitation method, characterized by FTIR, XRD, and SEM techniques, and used in batch procedures for the sorption of Cr(VI) and/or Zn(II) in monoelement solutions as well as in a competitive manner, aiming at the decontamination of waters and effluents. Among the sorption parameters investigated, the pH, kinetic, mass and sorption capacity of the biosorbent, and the competition between Cr(VI) and Zn(II) for the sorption sites will be assessed. The effect of YB magnetization on the efficiency of metal ions removal in aqueous medium will also be monitored during the development of this investigation, since all the tests will also be performed with the in natura yeast (YB). The adsorption isotherms models of Langmuir, Freundlich, and Dubinin-Radushkevich will be used to evaluate the experimental data. This proposal is related to the Research Project Grant "Development of adsorbent materials from yeast biomass residue from industrial fermentation processes to remove emerging contaminants in water and effluents" (FAPESP - Proc. 2016 / 06271-4).