Effectiveness of solar water disinfection in the era of COVID-19 (SARS-CoV-2) pandemic for contaminated water/wastewater treatment considering UV effect and temperature

Abstract

The COVID-19 pandemic disturbed the world from the beginning of 2020. The virus is highly contagious and spread rapidly and the number of infections increases exponentially. The high excessive number of patients and presence of the SARS-CoV-2 in human excreta and urine even after the infected person’s respiratory tests were negative, results in heavy load of viral in various water bodies. Numerous studies reported the presence of SARS-CoV-2 in wastewater samples. The risk of contaminating water bodies in the regions which suffer from the lack of proper sanitation system and wastewater treatment plants (mostly in developing countries) is higher. Since solar water disinfection (SODIS) is usually used by people in developing countries, there is a concern about using this method during the pandemic. Because the SARS-CoV-2 can be eliminated by high temperature (>56°C) and UVC wavelength (100-280 nm) while SODIS systems mainly work at lower temperature (<45°C) and use the available UVA (315-400 nm). Thus, during a situation like the ongoing pandemic using SODIS method for wastewater treatment (or providing drinking water) is not a reliable method. It should be reminded that the main aim of the present study is not just to give insights about the possibilities and risks of using SODIS during the ongoing pandemic but it has broader prospect for any future outbreak/pandemic that results in biological contamination of water bodies. Nevertheless, some experimental studies seem to be necessary by all researchers under conditions similar to developing countries.

Integration of renewable energy in wastewater treatment during COVID-19 pandemic: Challenges, opportunities, and progressive research trends

“…Increase the temperature from 18°C to 30°C without any catalyst, and the inactivation time can be shortened to even one hour at 56°C, reducing the time from 40 days to 24 days. In addition, the virus appears to be susceptible to freezing and thawing but remains stable at room temperature ( Parsa et al 2021 ).…”

Elucidating the role of environmental management of forests, air quality, solid waste and wastewater on the dissemination of SARS-CoV-2

“…However, well-maintained activated sludge processes may have enhanced disinfection effectivity, which may be expensive for other developing countries ( Craggs et al, 2014 ; Arif et al, 2020 ; Nasseri et al 2021 ; Serra-Compte et al, 2021 ). Additionally, temperatures higher than 40°C are needed for UV through solar stills to effectively inactivate SARS-CoV-2 in wastewater ( Parsa, 2021 ; Parsa et al, 2021 ).…”

Review of Method and a New Tool for Decline and Inactive SARS-CoV-2 in Wastewater Treatment

“…2012 ). Moreover, UV light is considered one of the most effective methods for disinfecting biologically contaminated water ( Parsa et al. 2021 ).…”

“…These types of UV light are abbreviated as UVA, UVB, and UVC, respectively (UVA photons have shallow energy, while UVC photons have enough energy to damage bacteria's DNA) ( Darnell et al. 2004 , Parsa et al. 2021 ).…”

“…In SODIS, UV content, temperature, and time are critical parameters. Moreover, UVC wavelengths are entirely absorbed by the Ozone layer, which means that pathogens, including viruses, can be damaged by the direct effect of UV on genomes as well as indirectly by endogenous or exogenous factors ( Parsa et al. 2021 ).…”