TY - JOUR
T1 - Novel Visible Light-Driven Photocatalytic Chlorine Activation Process for Carbamazepine Degradation in Drinking Water
AU - Cheng, Zihang
AU - Ling, Li
AU - Wu, Zihao
AU - Fang, Jingyun
AU - Westerhoff, Paul
AU - Shang, Chii
N1 - Funding Information:
The authors declare the following competing financial interest(s): Some of the authors are coinventors on the Hong Kong University of Science and Technologyowned intellectual property that is in the process of being licensed. Conflicts of interest are managed through regular disclosure to the Hong Kong University of Science and Technology, Technology Transfer Center. This work was partially funded by the Hong Kong Research Grants Council (T21-604/19-R) and the National Science Foundation (EEC-1449500) Nanosystems Engineering Research Center on Nanotechnology-Enabled Water Treatment. Acknowledgments
Funding Information:
Some of the authors are coinventors in the Hong Kong University of Science and Technology-owned intellectual property that is in the process of being licensed. Conflicts of interest are managed through regular disclosure to the Hong Kong University of Science and Technology, Technology Transfer Center. This work was partially funded by the Hong Kong Research Grants Council (16203820 and T21-604/19-R) and the National Science Foundation (EEC-1449500) Nanosystems Engineering Research Center on Nanotechnology-Enabled Water Treatment.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/9/15
Y1 - 2020/9/15
N2 - Photolysis of free chlorine (HOCl/ClO-) is an advanced oxidation process (AOP) to produce hydroxyl (HO•) and other radicals for refractory micropollutant degradation. However, HOCl/ClO- is only conducive to activation and production of radicals by ultraviolet (UV) light. For the first time, we show the use of visible light (>400 nm) to produce HO• and ClO•, through use of graphitic carbon nitride (g-C3N4) and photogenerated hvb+, ecb-, and O2•- in the presence of HOCl/ClO-, which was termed visible light g-C3N4-enabled chlorine AOP (VgC-AOP). The VgC-AOP increased the pseudo first-order degradation rate constant of a model micropollutant, carbamazepine, by 16 and 7 times higher than that without g-C3N4 and HOCl/ClO-, respectively, and remained active over multiple use cycles. Effects of water quality [pH, alkalinity, Cu(II), and natural organic matter (NOM)] and the operational conditions (g-C3N4 and HOCl/ClO- concentrations, irradiation wavelength, and dose) were investigated. Of particular significance is its superior performance in the presence of NOM, which absorbs less light at visible light wavelengths and scavenges less surface-bonded reactive species, compared against UV/TiO2 or UV/chlorine AOPs. The VgC-AOP is practically relevant, feasible, and easily implementable and it expands the potential types of light sources (e.g., LEDs and solar light).
AB - Photolysis of free chlorine (HOCl/ClO-) is an advanced oxidation process (AOP) to produce hydroxyl (HO•) and other radicals for refractory micropollutant degradation. However, HOCl/ClO- is only conducive to activation and production of radicals by ultraviolet (UV) light. For the first time, we show the use of visible light (>400 nm) to produce HO• and ClO•, through use of graphitic carbon nitride (g-C3N4) and photogenerated hvb+, ecb-, and O2•- in the presence of HOCl/ClO-, which was termed visible light g-C3N4-enabled chlorine AOP (VgC-AOP). The VgC-AOP increased the pseudo first-order degradation rate constant of a model micropollutant, carbamazepine, by 16 and 7 times higher than that without g-C3N4 and HOCl/ClO-, respectively, and remained active over multiple use cycles. Effects of water quality [pH, alkalinity, Cu(II), and natural organic matter (NOM)] and the operational conditions (g-C3N4 and HOCl/ClO- concentrations, irradiation wavelength, and dose) were investigated. Of particular significance is its superior performance in the presence of NOM, which absorbs less light at visible light wavelengths and scavenges less surface-bonded reactive species, compared against UV/TiO2 or UV/chlorine AOPs. The VgC-AOP is practically relevant, feasible, and easily implementable and it expands the potential types of light sources (e.g., LEDs and solar light).
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U2 - 10.1021/acs.est.0c03170
DO - 10.1021/acs.est.0c03170
M3 - Article
C2 - 32794774
AN - SCOPUS:85091125682
SN - 0013-936X
VL - 54
SP - 11584
EP - 11593
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 18
ER -