Modelling the UV-LED based chlorine photodecay and radical formation at different wavelengths and pHs

Authors

Ran Yin, Technological and Higher Education Institute of Hong Kong (THEi)
Chao Wang, Technological and Higher Education Institute of Hong Kong (THEi)Follow
Li Ling, Hong Kong University of Science and TechnologyFollow
Chii Shang, Hong Kong University of Science and TechnologyFollow

Document Type

Conference Proceeding

Publication Date

2018

Keywords

Wavelength-dependency, Chlorine photolysis, UV-LED

Abstract

An empirical model that incorporates the chlorine photodecay rate constants, quantum yields, and molar absorption coefficients of hypochlorous acid (HOCl) and hypochlorite (OCl-) was established and used to predict the chlorine photodecay rate at any wavelength (255–300 nm) and pH (5–10) in this study. The prediction of the chlorine photodecay rates at the four wavelengths (i.e., 255, 265, 285 and 300 nm) and two pHs (i.e., pHs 6 and 6 7) was well validated against the experimental results using UV-LEDs as light sources. The wavelength- and pH-7 dependency on the formation of reactive radical species from chlorine photolysis were also investigated in this study. We also provide implications of UV wavelength dependency on chlorine photodecay and its radical generation at different pHs in real-world applications.

Source Publication

LET 2018 - The 15th IWA Leading Edge Conference on Water and Waste Water Technologies, 27-31 May 2018, Nanijing, China

First Page

1

Last Page

6

Publisher Statement

The International Water Association

Recommended Citation

Yin, R.,Wang, C.,Ling, L.,& Shang, C. (2018). Modelling the UV-LED based chlorine photodecay and radical formation at different wavelengths and pHs. LET 2018 - The 15th IWA Leading Edge Conference on Water and Waste Water Technologies, 27-31 May 2018, Nanijing, China, 1-6. Retrieved from https://repository.vtc.edu.hk/thei-fac-sci-tech-sp/467