Abstract
Peroxydisulfate (PDS) is a common oxidant for organic contaminant remediation. PDS is typically activated by metal catalysts to generate reactive radicals. Unfortunately, as radicals are non-selective and metal catalysts may cause secondary contamination, alternative selective non-radical pathways and non-metal catalysts need attention. Here we investigated PDS oxidation of commonly detected antibiotic Norfloxacin (NOR) using cyanobacterial nitrogen rich biochars (CBs) as catalysts. NOR was fully degraded by CB pyrolysed at 950 °C (CB950) within 120 min. CB950 caused threefold faster degradation than low pyrolysis temperature (PT) CBs and achieved a maximum surface area normalized rate constant of 4.38 × 10−2 min−1 m−2 L compared to widely used metal catalysts. CB950 maintained full reactivity after four repeated uses. High defluorination (82%) and mineralization (>82%) were observed for CB950/PDS. CBs were active over a broad pH range (3−10), but with twice as high rates under alkaline compared with neutral conditions. NOR is degraded by organic, •OH and SO4•− radicals in low PT CBs/PDS systems, where the presence of MnII promotes radical generation. Electron transfer reactions with radicals supplemented dominate high PT CBs/PDS systems. This study demonstrates high PT biochars from algal bloom biomass may find use as catalysts for organic contaminant oxidation.
Originalsprog | Engelsk |
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Artikelnummer | 129655 |
Tidsskrift | Journal of Hazardous Materials |
Vol/bind | 439 |
Antal sider | 15 |
ISSN | 0304-3894 |
DOI | |
Status | Udgivet - 2022 |
Bibliografisk note
Funding Information:The authors thank the China Scholarship Council (CSC) and the Sino-Danish Center for financial support to Chen Wang. Nadia Dodge and Poul Erik Jensen were supported by the Novo Nordisk Foundation NNF19OC0057634 . Chen Wang thanks Anita S. Sandager, Birgitte B. Rasmussen and Henriette Rifbjerg Erichsen for helping carrying out the BET, C/N, ICP-OES, UPLC/MS, EPR analyzes.
Funding Information:
The authors thank the China Scholarship Council (CSC) and the Sino-Danish Center for financial support to Chen Wang. Nadia Dodge and Poul Erik Jensen were supported by the Novo Nordisk Foundation NNF19OC0057634. Chen Wang thanks Anita S. Sandager, Birgitte B. Rasmussen and Henriette Rifbjerg Erichsen for helping carrying out the BET, C/N, ICP-OES, UPLC/MS, EPR analyzes.
Publisher Copyright:
© 2022 The Authors