Reliability of thermal desalination (solar stills) for water/wastewater treatment in light of COVID-19 (novel coronavirus "SARS-CoV-2") pandemic: What should consider?

Abstract

The COVID-19 pandemic disturbed the world from the beginning of 2020. The high excessive number of patients and the presence of the SARS-CoV-2 in human excreta and urine even after the infected person's respiratory tests were negative, results in a heavy load of viral in various water bodies and mostly untreated wastewaters. In the present study, the reliability of using small-scale solar thermal desalination systems (solar stills) during a situation like the COVID-19 pandemic is discussed. Pollution of water bodies through the SARS-CoV-2 via numerous routes increases the risk of contaminating the feed water and subsequently the whole structure of solar stills. Since the transmission of pathogens (particle size: 0.5-3 μm) via droplets of water in solar still is reported before, transmitting of SARS-CoV-2 via droplets of water which multiple times smaller (particle size: 60-140 nm) than those pathogens is a concern. The most important issue which must be highlighted is that solar stills worked at low-temperature while the viability and survival of the SARS-CoV-2 in various water matrices in the temperature range (4-37 °C) for several days is reported. In this regard, using solar stills during the COVID-19 pandemic need further consideration by all researchers and people around the world.

Keywords: COVID-19; Environmental contamination; Pathogens; Solar desalination; Wastewater treatment; Waterborne disease.

Graphical abstract

Fig. 1

Schematic of solar still.

Fig. 2

application of solar still for separation of various impurities.

Fig. 3

Productivity of various solar stills with respect to the temperature.

Fig. 4

Possible routes for contamination of water bodies.

Fig. 5

Some parameters and methods that affecting the viability of the SARS-CoV-2.

Fig. 6

Viability of the SARS-CoV-2 in solution with respect to temperature [163].

Fig. 7

The average T₉₀ for the SARS-CoV-2 in tap water [172].

Fig. 8

The average T₉₀ for the SARS-CoV-2 in Autoclaved wastewater [172].

Fig. 9

The average T₉₀ for the SARS-CoV-2 in untreated wastewater [172].