Efficient Removal of Cr(VI) Ions in Petrochemical Wastewater Using Fe3O4@Saccharomyces cerevisiae Magnetic Nanocomposite

Saccharomyces cerevisiae (SC) is a widely available biobased source for function material. In this work, a kind of new efficient magnetic composite adsorbent containing Fe3O4 and SC was prepared successfully and used for the removal of Cr(VI) ions in petrochemical wastewater. The morphology and structure of this magnetic adsorbent were characterized with FT-IR, TG, XRD, VSM, SEM and XPS. The effect of the different factors such as pH, adsorption time, initial Cr(VI) ions concentration and adsorption temperature on the adsorption behavior were investigated. The results showed that 10%-Fe3O4@SC exhibited high removal rate, reutilization and large removal capacity. The corresponding removal capacity and removal rate could reach 128.03 mg/g and 96.02% when the pH value was 2, adsorption time was 180 min, and initial Cr(VI) ions concentration were 80 mg/L at 298 K. The kinetics followed the pseudo-first-order, which indicated that the adsorption behavior of 10%-Fe3O4@SC for Cr(VI) ions belonged to the physical adsorption and chemical adsorption co-existence. The thermodynamic study showed that the adsorption process was spontaneous and exothermic. It still showed better adsorption performance and reutilization after the fifth adsorption-desorption experiment. The possible mechanism of Cr(VI) ions adsorption onto the 10%-Fe3O4@SC magnetic adsorbent has been discussed. Hence, this new adsorbent will be a candidate for industry-level applications in petrochemical wastewater containing Cr(VI) ions.