Visible light-driven g-C3N4 peroxymonosulfate activation process for carbamazepine degradation: Activation mechanism and matrix effects

Zihang Cheng; Li Ling; Jingyun Fang; Chii Shang

doi:10.1016/j.chemosphere.2021.131906

Visible light-driven g-C₃N₄ peroxymonosulfate activation process for carbamazepine degradation: Activation mechanism and matrix effects

Chemosphere. 2022 Jan;286(Pt 3):131906. doi: 10.1016/j.chemosphere.2021.131906. Epub 2021 Aug 17.

Authors

Zihang Cheng¹, Li Ling², Jingyun Fang³, Chii Shang⁴

Affiliations

¹ Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
² Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Electronic address: celingli@ust.hk.
³ Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510275, PR China.
⁴ Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. Electronic address: cechii@ust.hk.

PMID: 34416590
DOI: 10.1016/j.chemosphere.2021.131906

Abstract

In this study, g-C₃N₄ with a high portion of tri-s-triazine groups was synthesized to activate peroxymonosulfate (PMS) under visible light irradiation, termed as Vis/g-C₃N₄/PMS process, to degrade one frequently detected recalcitrant micropollutant carbamazepine (CBZ). The Vis/g-C₃N₄/PMS process increased pseudo first-order degradation rate constant of CBZ by 2 times compared with that in the absence of PMS. The enhanced CBZ degradation was because of the production of HO and SO₄^- from the PMS activation, but not the enhanced charge separation of g-C₃N₄ due to the presence of PMS. The Vis/g-C₃N₄/PMS process is insensitive to dissolved oxygen, chloride and bicarbonate concentrations, effective over a wide pH range from 6.0 to 10.0, and less affected by high concentrations of natural organic matter compared with the UV/chlorine and UV/TiO₂ processes. In addition, photocatalytic activity of g-C₃N₄ remains stable over 5-cycle of reuse. These features make the process practically relevant and implementable in degrading micropollutants in drinking water, treated wastewater, surface water, groundwater, etc., using more efficient visible light LEDs or even sunlight.

Keywords: Carbamazepine; Peroxymonosulfate; Sulfate radical; Visible light; g-C(3)N(4).

MeSH terms

Carbamazepine
Light*
Peroxides*
Wastewater

Substances

Peroxides
Waste Water
peroxymonosulfate
Carbamazepine