Enhanced photocatalytic degradation of ciprofloxacin over Bi2O3/(BiO)2CO3heterojunctions: Efficiency, kinetics, pathways, mechanisms and toxicity evaluation

Meijuan Chen, Jie Yao, Yu Huang, Han Gong, Wei Chu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

99 Citations (Scopus)

Abstract

In this study, the degradation of antibiotic ciprofloxacin (CIP) over Bi2O3/(BiO)2CO3heterojunctions under simulated solar light irradiation (SSL-Bi2O3/(BiO)2CO3) was examined for the first time. The results showed that the Bi2O3/(BiO)2CO3heterojunctions dramatically improved CIP decay efficiency. The effect of parameters showed that the CIP decay was optimized with the Bi2O3/(BiO)2CO3dosage of 0.5 g/L and a wide pH range of 4.0–8.3, based on which, a kinetic model was derived to predict the remaining CIP concentration. It was found that the presence of anions like SO42−, NO3−and HCO3−decelerated the CIP decay, while the co-existence of Cl−accelerated the CIP decay. Six degradation intermediates were identified by ultra-performance liquid chromatography coupled with mass analyzer (UPLC/MS) and ion chromatographic (IC) analysis, and the decay pathways and degradation mechanism of CIP were proposed by combining the experiment data with theoretical calculation of frontier electron densities. Hydroxyl radical's reaction, photo-hole (h+) oxidation and reductive defluorination were found to involve in the CIP decay. The efficient alleviation on total organic carbon (TOC) and toxicity indicated that the complete mineralization and de-toxicity are possible by this system with sufficient reaction time.
Original languageEnglish
Pages (from-to)453-461
Number of pages9
JournalChemical Engineering Journal
Volume334
DOIs
Publication statusPublished - 15 Feb 2018

Keywords

  • Bi O /(BiO) CO 2 3 2 3
  • Ciprofloxacin
  • Degradation mechanism
  • Kinetics model
  • Toxicity

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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