Synthesis,characterization, and application of yeast-based magnetic bionanocomposite for the removal of Cu(II) from water

Abstract

Due to the amount of yeast residues generated by the industries and their high capacity as biosorbent, this work proposes the use of yeast biomass in natura (YB) or modified with ferromagnetic nanoparticles (Fe₃O₄) (YB-MNP) for Cu(II) removal from water. Synthesized YB-MNP, YB, and magnetite alone (MNP) were characterized by FTIR, XRD, and SEM. It was observed the efficient impregnation of magnetite on the surface of the biomass. Copper sorption was evaluated in batch tests using 100?mg/L of Cu(II) solution at pH 5.5, and the supernatant was analyzed by FAAS for Cu determination. Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm models were applied to fit the experimental data. A favorable sorption process was observed for all the materials, mainly for the D–R model adjusted to the bionanocomposite data (YB-MNP), with r² = 0.9950 and a low error (χ² = 0.0427) associated to the model. Theoretical and experimentally Cu(II) sorption capacities were fairly similar, 8.6?±?0.1 and 8.3?±?0.2?mg/g, respectively.