Water disinfection by the UVA/electro-Fenton process under near neutral conditions: Performance and mechanisms

Xiongjian Chen; Ziyu Chen; Chun-Yan Lin; Riyao Chen; Peiwen Huang; Yanchao Jin

doi:10.1016/j.chemosphere.2022.136488

Water disinfection by the UVA/electro-Fenton process under near neutral conditions: Performance and mechanisms

Chemosphere. 2022 Dec;308(Pt 3):136488. doi: 10.1016/j.chemosphere.2022.136488. Epub 2022 Sep 21.

Authors

Xiongjian Chen¹, Ziyu Chen², Chun-Yan Lin³, Riyao Chen⁴, Peiwen Huang², Yanchao Jin⁵

Affiliations

¹ College of Materials and Chemical Engineering, Minjiang University, Fuzhou, 350108, China; College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, 350007, China.
² College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, 350007, China.
³ College of Materials and Chemical Engineering, Minjiang University, Fuzhou, 350108, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou, 350007, China. Electronic address: lincy@mju.edu.cn.
⁴ College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, 350007, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou, 350007, China.
⁵ College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, 350007, China; Fujian Key Laboratory of Pollution Control & Resource Reuse, Fuzhou, 350007, China. Electronic address: yanchao_jin@fjnu.edu.cn.

PMID: 36152825
DOI: 10.1016/j.chemosphere.2022.136488

Abstract

An efficient and thorough water disinfection is critical for human health. In this study, UVA-LEDs, nitrilotriacetic acid (NTA) and a boron-doped diamond anode were respectively used as the UVA source, the iron chelator and the anode for the UVA/electro-Fenton (E-Fenton) reaction to treat wastewater. The disinfection performance of the UVA/E-Fenton had been investigated. The mechanisms of the E. coli inactivation had been clarified. The results showed that complete disinfection (about 5.6-log removal) could be achieved within 50 min at a certain condition due to the synergistic effort of the UVA, anodic oxidation and the electro-Fenton. The quenching experiments and the electron paramagnetic resonance (EPR) detection indicated that •OH, •O₂^- and ¹O₂ play important roles for inactivating E. coli. The results of SEM images and genomic DNA electrophoresis suggested that both the cell structure and the DNA had been thoroughly destroyed during the UVA/E-Fenton process. Increasing the UVA irradiation, oxygen bubbling could improve the disinfection rate, while it also would increase the energy consumption. The appropriate Fe and NTA ratio was 1:2 to realize an efficient Fenton reaction under near neutral condition. Complete disinfection was also achieved within 50 min when it used for treating real wastewater. Thus, the UVA/E-Fenton process is a satisfied way for water disinfection.

Keywords: Boron-doped diamond anode; Disinfection; Electro-fenton; Nitrilotriacetic acid; Ultraviolet A.

MeSH terms

Boron / chemistry
Diamond / chemistry
Disinfection* / methods
Electrodes
Escherichia coli
Humans
Hydrogen Peroxide / chemistry
Iron / chemistry
Iron Chelating Agents
Nitrilotriacetic Acid
Oxidation-Reduction
Oxygen / analysis
Wastewater* / analysis
Water / analysis

Substances

Iron Chelating Agents
Waste Water
Water
Diamond
Hydrogen Peroxide
Iron
Nitrilotriacetic Acid
Boron
Oxygen