Degradation of ciprofloxacin by persulfate activated by Fe(III)-doped BiOCl composite photocatalyst

Gen Liu; Yingzi Lin; Siwen Li; Chunyan Shi; Dongyan Zhang; Lei Chen

doi:10.1007/s11356-023-28490-0

Degradation of ciprofloxacin by persulfate activated by Fe(III)-doped BiOCl composite photocatalyst

Environ Sci Pollut Res Int. 2023 Aug;30(37):87830-87850. doi: 10.1007/s11356-023-28490-0. Epub 2023 Jul 11.

Authors

Gen Liu¹, Yingzi Lin^{2

3}, Siwen Li¹, Chunyan Shi⁴, Dongyan Zhang⁵, Lei Chen⁵

Affiliations

¹ School of Environment, Northeast Normal University, No. 2555 Jingyue Street, Changchun, 130117, Jilin, China.
² Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, Changchun, 130118, China. linyingzi@jlju.edu.cn.
³ School of Municipal & Environmental Engineering, Jilin Jianzhu University, Changchun, 130118, China. linyingzi@jlju.edu.cn.
⁴ The University of Kitakyushu, 1-1 Hibikino, Wakamatsuku, Kitakyushu, Fukuoka, Japan.
⁵ School of Municipal & Environmental Engineering, Jilin Jianzhu University, Changchun, 130118, China.

PMID: 37434054
DOI: 10.1007/s11356-023-28490-0

Abstract

Fe-BOC-X photocatalyst was successfully prepared by solvothermal method. The photocatalytic activity of Fe-BOC-X was determined by ciprofloxacin (CIP), a typical fluoroquinolone antibiotic. Under sunlight irradiation, all Fe-BOC-X showed better CIP removal performance than original BiOCl. In comparison, the photocatalyst with iron content of 50 wt% (Fe-BOC-3) has excellent structural stability and the best adsorption photodegradation efficiency. The removal rate of CIP (10 mg/L) by Fe-BOC-3 (0.6 g/L) reached 81.4% within 90 min. At the same time, the effects of photocatalyst dosage, pH, persulfate, persulfate concentration, and combinations of different systems (PS, Fe-BOC-3, Vis/PS, Vis/Fe-BOC-3, Fe-BOC-3/PS, and Vis/Fe-BOC-3/PS) on the reaction were systematically discussed. In reactive species trapping experiments, electron spin resonance (ESR) signals revealed that the photogenerated holes (h⁺), hydroxyl radical (•OH), sulfate radical (•SO₄^-), and superoxide radical (•O₂^-) played an important role in CIP degradation; hydroxyl radicals (•OH) and sulfate radicals (•SO₄^-) play a major role. Various characterization methods have demonstrated that Fe-BOC-X has larger specific surface area and pore volume than original BiOCl. UV-vis DRS indicate that Fe-BOC-X has wider visible light absorption and faster photocarrier transfer and provides abundant surface oxygen absorption sites for effective molecular oxygen activation. Accordingly, a large number of active species were produced and participated in the photocatalytic process, thus effectively promoting the degradation of ciprofloxacin. Based on HPLC-MS analysis, two possible decomposition pathways of CIP were finally proposed. The main degradation pathways of CIP are mainly due to the high electron density of piperazine ring in CIP molecule, which is mainly attacked by various free radicals. The main reactions include piperazine ring opening, decarbonylation, decarboxylation, and fluorine substitution. This study can better open up a new way for the design of visible light driven photocatalyst and provide more ideas for the removal of CIP in water environment.

Keywords: Bismuth oxychloride; Ciprofloxacin; Persulfate; Visible photocatalysis.

MeSH terms

Catalysis
Ciprofloxacin* / chemistry
Ferric Compounds*
Light
Oxygen
Piperazines

Substances

Ciprofloxacin
Ferric Compounds
Oxygen
Piperazines

Abstract

MeSH terms

Substances

Grants and funding