This study demonstrated the application of biogenic sulfidated iron (B-FeS), produced via anaerobic digestion of Desulfovibrio desulfuricans using sulfate as the terminal electron acceptor, for peroxide activation. B-FeS was assessed against chemically prepared zerovalent and sulfidated iron (ferrous sulfide and pyrite) with respect to their ability to activate peroxydisulfate (PDS) and H2O2. Regardless of the peroxide type, B-FeS outperformed benchmark iron activators in treating 4-chlorophenol due to its resistance to iron corrosion and the high content of reduced sulfur. The roles of oxidizing radicals were confirmed based on the effects of alcohol-based quenchers, multi-activity assessment, electron paramagnetic resonance spectral features, and product analysis. The pH-dependent efficiency of sulfoxide-to-sulfone conversion suggested that high-valent iron species acted as the secondary oxidant in all iron/peroxide systems, and the contribution was more pronounced when PDS and B-FeS were used. Microbial sulfidation as a catalyst regeneration strategy recovered the peroxide activation capacity of oxidized B-FeS.
Bibliographical noteFunding Information:
This study was supported by a National Research Foundation of Korea grant funded by the Korean government [grant no. NRF-2021R1A2C2003763 ], and by the Korea Ministry of Environment [grant no. RE202101610 ].
© 2021 Elsevier B.V.
- Biogenic sulfidated iron
- High-valent iron
- Peroxide activation
- Sulfate radical
- Sulfate-reducing bacteria
ASJC Scopus subject areas
- Environmental Science(all)
- Process Chemistry and Technology