Pulsed discharge plasma induced WO3 catalysis for synergetic degradation of ciprofloxacin in water: Synergetic mechanism and degradation pathway

He Guo; Nan Jiang; Huijuan Wang; Kefeng Shang; Na Lu; Jie Li; Yan Wu

doi:10.1016/j.chemosphere.2019.05.011

Pulsed discharge plasma induced WO₃ catalysis for synergetic degradation of ciprofloxacin in water: Synergetic mechanism and degradation pathway

Chemosphere. 2019 Sep:230:190-200. doi: 10.1016/j.chemosphere.2019.05.011. Epub 2019 May 12.

Authors

He Guo¹, Nan Jiang², Huijuan Wang³, Kefeng Shang⁴, Na Lu⁴, Jie Li⁴, Yan Wu⁴

Affiliations

¹ Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian University of Technology, Dalian, 116024, China; School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
² Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian University of Technology, Dalian, 116024, China; School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China; School of Electrical Engineering, Dalian University of Technology, Dalian, 116024, China. Electronic address: jiangnan@dlut.edu.cn.
³ School of Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212013, China.
⁴ Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Dalian University of Technology, Dalian, 116024, China; School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China; School of Electrical Engineering, Dalian University of Technology, Dalian, 116024, China.

PMID: 31103865
DOI: 10.1016/j.chemosphere.2019.05.011

Abstract

Pulsed discharge plasma (PDP) was adopted to induce WO₃ for synergetic degradation of ciprofloxacin (CIP) in water. WO₃ was firstly characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS), Photocurrents and Photoluminescence. The degradation results showed that PDP could induce WO₃ photocatalysis successfully, and a synergetic effect was established in PDP/WO₃ system. After 60 min treatment time, 0.16 g/L WO₃ increased the CIP removal from 71.3% to 99.6%, with the enhancement of the first-order kinetic constant from 0.020 min^-1 to 0.081 min^-1. Then, the effect of peak voltage, air flow rate and pH on CIP removal was evaluated. Active species trapping test verified that ·OH and ·O₂^- played the major role for plasma-degradation of CIP degradation, whereas OH and h⁺ were conductive to catalytic degrade CIP. WO₃ addition lead to the decline of O₃ and enhancement of OH no matter in deionized water or CIP solution. The degradation process was explored using fluorescence spectrograph, liquid chromatography-mass spectrometry (LC-MS) and ion chromatography (IC). Finally, the possible degradation pathways of CIP degradation were proposed. The reuse test suggested WO₃ possessed excellent catalytic performance as well as good stability.

Keywords: Ciprofloxacin; Degradation pathway; Pulsed discharge plasma; Synergetic mechanism; WO(3).

MeSH terms

Catalysis
Ciprofloxacin / analysis*
Kinetics
Models, Theoretical
Oxidation-Reduction
Oxides / chemistry*
Photochemistry
Plasma Gases / chemistry*
Tungsten / chemistry*
Water Pollutants, Chemical / analysis*
Water Purification / methods*

Substances

Oxides
Plasma Gases
Water Pollutants, Chemical
Ciprofloxacin
tungsten oxide
Tungsten