Efficient degradation of norfloxacin using a novel biochar-supported CuO/Fe3O4 combined with peroxydisulfate: Insights into enhanced contribution of nonradical pathway

Song Cai; Tongshuai Wang; Congyi Wu; Wei Tang; Jiawei Chen

doi:10.1016/j.chemosphere.2023.138589

Efficient degradation of norfloxacin using a novel biochar-supported CuO/Fe₃O₄ combined with peroxydisulfate: Insights into enhanced contribution of nonradical pathway

Chemosphere. 2023 Jul:329:138589. doi: 10.1016/j.chemosphere.2023.138589. Epub 2023 Apr 4.

Authors

Song Cai¹, Tongshuai Wang², Congyi Wu³, Wei Tang¹, Jiawei Chen⁴

Affiliations

¹ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China.
² State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China; China Household Elect Appliance Res Inst CHEARDI, Beijing, 100053, PR China.
³ School of Science, China University of Geosciences, Beijing, 100083, PR China.
⁴ State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, PR China. Electronic address: chenjiawei@cugb.edu.cn.

PMID: 37023897
DOI: 10.1016/j.chemosphere.2023.138589

Abstract

Nonradical persulfate oxidation techniques have evolved as a new contaminated water treatment approach due to its great tolerance to water matrixes. The catalysts of CuO-based composites have received much attention in that aside from SO₄^•-/^•OH radicals, the nonradicals of singlet oxygen (¹O₂) can be also generated during persulfate activation via CuO. However, the issues regarding particles aggregation and metal leaching from the catalysts during the decontamination process remain to be addressed, which could have a remarkable impact on the catalytic degradation of organic pollutants. Accordingly in the present study, a novel biochar-supported bimetallic Fe₃O₄-CuO catalyst (CuFeBC) was facilely developed to activate peroxodisulfate (PDS) for the degradation of norfloxacin (NOR) in aqueous solution. The results showed CuFeBC has a superior stability against metal ions Cu/Fe leaching, and NOR (30 mg L^-1) was degraded at 94.5% within 180 min in the presence of CuFeBC (0.5 g L^-1) and PDS (6 mM) in pH 8.5. The scavenging of reactive oxygen species and electron spin resonance analysis revealed that ¹O₂ dominated the degradation of NOR. Compared with pristine CuO-Fe₃O₄, the interaction between biochar substrate and metal particles could significantly enhance the contribution of the nonradical pathway to NOR degradation from 49.6% to 84.7%. Biochar substrate could efficiently reduce the leaching of metal species from the catalyst, thereby maintaining excellent catalytic activity and lasting reusability of the catalyst. These findings could enlighten new insights into fine-tuning radical/nonradical processes from CuO-based catalysts for the efficient remediation of organic contaminants in polluted water.

Keywords: Biochar; Nonradical pathway; Norfloxacin; Peroxodisulfate; Singlet oxygen.

MeSH terms

Charcoal*
Copper
Norfloxacin*

Substances

biochar
cupric oxide
Norfloxacin
Charcoal
Copper