Enhanced removal and recovery of heavy metals from acid mine drainage using nFeS@GS biosynthesized by Geobacter sulfurreducens

• Published in: Journal of environmental chemical engineering 2024-12, Vol.12 (6), p.114687, Article 114687
• Main Authors: Chen, Jinyang, Wu, Juanli, Liu, Ping, Gan, Li, Chen, Zuliang
• Format: Article
• Language: English
• Subjects: Acid mine drainage; Biohybrid; Ferrous sulfide nanoparticles; Heavy metals; Removal and recovery
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2024.114687

Efficient removal and recovery of heavy metals (HMs) from acid mine drainage (AMD) is crucial for both protecting mine ecosystems and reclaiming valuable HMs resources. In this study, biohybrid with ferrous sulfide nanoparticles (nFeS@GS) were biosynthesized via Geobacter sulfurreducens (GS) and employed for the removal and recovery of HMs from AMD. Initially, nFeS@GS were successfully synthesized as confirmed by TEM and exhibited high efficiencies in removing Cu2+ and Pb2+ in solution, respectively. This occurred because bio-nFeS and GS cells synergistically enhanced the removal of Cu2+ and Pb2+. What is more, the removal efficiencies of various HMs from real AMD using nFeS@GS remained high, with documented rates of 87.9 % for Cu2+, 96.2 % for Pb2+, 95.1 % for Cd2+, 81.4 % for Ni2+, 80.9 % for Mn2+, and 91.9 % for Zn2+. Subsequent characterization of the removal function through 3D-EEM, Bio-TEM, XRD, FTIR and XPS analyses revealed substantial organic capping agents derived from GS adhering to the bio-nFeS, forming surface complexes with Cu2+ and Pb2+, and Cu2+ was reduced to Cu+/Cu0. Zeta potential measurements, adsorption kinetics and reduction kinetics supported that the removal mechanism involved electrostatic interactions, surface complexation, ion exchange and reduction. Finally, nFeS@GS desorption rates of HMs exceeded 90.7 %, highlighting the efficacy of nFeS@GS for recovering HMs from AMD. These findings provide valuable and practical insights into the removal and recovery of HMs from AMD using biomaterials synthesized from microorganisms. [Display omitted] •A sustainable nFeS@GS composite derived from biosynthesis was designed.•The synergistic effect from adsorption of GS and reactivity of nFeS was observed.•A mechanism for removing Cu2+ and Pb2+ was based on adsorption and reduction.•The potential for removing and recycling heavy metals from AMD was discussed.