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Role of sulfide-modified nanoscale zero-valent iron on carbon nanotubes in nonradical activation of peroxydisulfate.
- Source :
-
Journal of Hazardous Materials . Jan2022, Vol. 422, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- Sulfamethoxazole (SMX) is highly persistent and difficult to remove, making it urgent to find an efficient method for alleviating the enormous environmental pressure of SMX. In this study, sulfide-modified nanoscale zero-valent iron on carbon nanotubes (S-nZVI@CNTs) was prepared to activate peroxydisulfate (PDS) for the degradation of SMX. The results showed that SMX was completely removed within 40 min (k obs =0.1058 min−1) in the S-nZVI@CNTs/PDS system. By analyzing quenching experiments and electron paramagnetic resonance (EPR), singlet oxygen (1O 2) was the main active species of the S-nZVI@CNTs/PDS system. 1O 2 might be mediated by the abundant carbonyl groups (C O) on carbon nanotubes through spectroscopic analyses. In addition, sulfur doping transitioned the activation pathway to a nonradical pathway. Spectroscopic analyses and electrochemical experiments confirmed that the formation of CNTs-PDS complexes and S-nZVI could promote electron transfer on the catalyst surface. Furthermore, the main degradation intermediates of SMX were identified, and five possible transformation pathways were proposed. The S-nZVI@CNTs/PDS system possessed advantages including high anti-interference (Cl-, NO3-, HA), a strong applicability, recyclability and a low PDS consumption, offering new insight into the degradation of antibiotic wastewater. [Display omitted] • S-nZVI@CNTs exhibited excellent performance for PDS activation to degrade SMX. • Carbonyl groups played a key role in the generation of singlet oxygen. • S-nZVI@CNTs combined with PDS to produce electron complexes. • Sulfide-modified nanoscale zero-valent iron accelerated electron transfer. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03043894
- Volume :
- 422
- Database :
- Academic Search Index
- Journal :
- Journal of Hazardous Materials
- Publication Type :
- Academic Journal
- Accession number :
- 153286530
- Full Text :
- https://doi.org/10.1016/j.jhazmat.2021.126949