Article

An aluminum-based reflective nanolens array that enhances the effectiveness of a continuous-flow ultraviolet disinfection system for livestock water

Changhoon Chai1,*, Jinhyung Park1
Author Information & Copyright
1Department of Applied Animal Science, Kangwon National University, Chuncheon 24341, Korea.
*Corresponding Author: Changhoon Chai, Department of Applied Animal Science, Kangwon National University, Chuncheon 24341, Korea, Republic of. Phone: +82-33-250-8641. E-mail: chchai@kangwon.ac.kr.

© Copyright 2022 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Climate change has worsened droughts and floods, and created conditions more likely to lead to pathogen contamination of surface water and groundwater. Thus, there is a growing need to disinfect livestock water. Ultraviolet (UV) irradiation is widely accepted as an appropriate method for disinfecting livestock water, as it does not produce hazardous chemical compounds and kills pathogens. However, UV-based disinfection inevitably consumes electricity, so it is necessary to improve UV disinfection effectiveness. Aluminum-based reflective nanolens arrays that enhanced the effectiveness of a continuous-flow ultraviolet (UV) water disinfection system were developed using electrochemical and chemical processes, including electropolishing and two-step anodization. A continuous UV disinfection system was custom designed and the parts were produced using a three-dimensional printer. Electropolished aluminum was anodized at 40 and 80 V in 0.3 M oxalic acid, at 120 and 160 V in 1.0 M phosphoric acid, and at 200 and 240 V in 1.5 M citric acid. The average nanolens diameters (<italic>D</italic>) of the aluminum-based reflective nanolens arrays prepared using 40, 80, 120, 160, 200, and 240 V anodization were 95.44, 160.98, 226.64, 309.90, 296.32, and 339.68 nm, respectively. Simple UV reflection behind irradiated water disinfected <italic>Escherichia coli </italic>O157:H7 in water more than did the non-reflective control. UV reflection and focusing behind irradiated water using an aluminum-based reflective nanolens array disinfected <italic>E. coli </italic>O157:H7 more than did simple UV reflection. Such enhancement of the UV disinfection effectiveness was significantly effective when a nanolens array with <italic>D</italic> 226.64 nm, close to the wavelength of the irradiated UV (254 nm), was used.

Keywords: Nanolens array; UV inactivation; anodic aluminum oxide; livestock water