Journal
JOURNAL OF ENVIRONMENTAL MANAGEMENT
Volume 350, Issue -, Pages -Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jenvman.2023.119597
Keywords
Multiple wavelength ultraviolet; Disinfection; Inactivation; DNA damage; ROS production
Categories
Ask authors/readers for more resources
In this study, an electron beam excitation multi-wavelength ultraviolet (EBE-MW-UV) system was established and found to have significantly higher microbial inactivation effects compared to single-wavelength UV-LEDs in water. Mechanism analysis revealed that EBE-MW-UV damaged microbial DNA and proteins, and generated additional reactive oxygen species, leading to microbial inactivation.
Due to the limitations of traditional ultraviolet (UV) in microbial inactivation in water, it is necessary to explore a more suitable and efficient UV disinfection method. In this study, an electron beam excitation multi-wavelength ultraviolet (EBE-MW-UV) system was established and aims to analyze its differential microbial inactivation capabilities in comparison to single-wavelength UV-LEDs in waterborne applications. Furthermore, the inactivation mechanisms of this system on microorganisms were explored. The results showed that EBE-MW-UV had significantly higher inactivation effects on the Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans in water compared to UV-LEDs (p < 0.05), and the inactivation effect of EBE-MW-UV on Escherichia coli and Pseudomonas aeruginosa at the same UV dose was 3.8 and 1.9 log higher than that of UV-LEDs, respectively, EBE-MW-UV exhibited better inactivation effects on Gram-negative bacteria. Further research found that, under the majority of irradiation doses, neither EBE-MW-UV nor UV-LEDs were significantly affected by the concentration of suspended solids (5 and 20 mg/L) or humic acids (2 and 5 mg/L) in the water. Mechanism analysis revealed that during the disinfection process of EBE-MW-UV, microbial DNA and proteins were initially damaged, which prevented the occurrence of dark repair and led to bacterial inactivation. In addition, UV irradiation led to the production of additional reactive oxygen species (ROS) inside the cells, increasing cell membrane permeability and exacerbating membrane damage. This was accompanied by a decrease in energy metabolism and depletion of ATP, ultimately resulting in microbial inactivation. Therefore, EBE-MW-UV demonstrated more effective disinfection than single-wavelength UV-LEDs, showing great potential. Our research gives new insights into the characteristics of multiple wavelength ultraviolet, and provides scientific basis for the selection of new light sources in the field of ultraviolet disinfection.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available