S. cerevisiae cells modified with nZVI: a novel magnetic biosorbent for nickel removal from aqueous solutions

The present study was conducted to evaluate the applicability of S. cerevisiae cells modified with nZVI (magnetic biosorbent) for the Ni(II) ions removal from aqueous solutions. This composite was synthesized in ethanol using a borohydride reduction method in atmospheric conditions and characterized by FTIR, XRD, and SEM analyses. Batch experiments were examined the effects of initial solution pH, magnetic biosorbent amount, contact time, initial Ni(II) concentration, and temperature. Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models were applied to the equilibrium data. The maximum biosorption capacity of the magnetic biosorbent was found to be relatively high (54.23 mg/g). The reductive power of the Fe-0 and functional groups on the yeast cell surface contributed to the removal of Ni(II) ions. The kinetics data were best described by the pseudo-secondorder kinetics model. Thermodynamics parameters were calculated from the experimental data. Ni(II) removal onto magnetic biosorbent was favorable, physicochemical in nature. Also, the Ni(II) removal onto magnetic biosorbent decreased with increasing in Na concentration in aqueous solutions. The results of this study suggest that the magnetic biosorbent is effective for Ni(II) removal from aqueous solutions.