Fungi-enabled hierarchical porous magnetic carbon derived from biomass for efficient remediation of As(iii)-contaminated water and soil: performance and mechanism

Abstract

In this study, fungi-enabled hierarchical porous magnetic carbon (FPC/nZVI) with an ultrahigh surface area was synthesized using fungal fermentation and used for efficient remediation of As(III) in water and soil. The synergistic impacts between the fungi-enabled porous carbon (FPC) matrix and nanoscale zero-valent iron (nZVI) for excellent As(III) adsorption ability was investigated under aerobic conditions. The results indicated that the prepared FPC/nZVI exhibited 3 times higher As(III) adsorption capacity (Q_max = 130.4 mg g⁻¹) than bare nZVI. In addition, electron spin resonance (ESR) results showed that FPC/nZVI could enhance As(III) oxidation through producing large amounts of reactive oxygen species including O₂⁻ and ˙OH. Moreover, FPC/nZVI could control As(III) vertical migration in soil and remove more than 70% As(III) from soil suspension using a magnet. Compared to the control group, the arsenic content in rice root and shoot treated with 3% FPC/nZVI in paddy soil decreased by 65% and 72%, respectively. Overall, this simple, low-cost and eco-friendly strategy using fungal fermentation pretreatment is promising for the preparation of hierarchical porous magnetic carbon to remediate As(III) in water and soil.