Reseachers call for study to find water treatment methods kill coronavirus

Two researchers call for more tests to find out whether water treatment methods are effective in killing SARS-CoV-19 and coronaviruses.

According to the researchers, the virus can be transported in microscopic water droplets, or aerosols, which enter the air through evaporation or spray.

University of California, Riverside associate professor of chemical and environmental engineering Haizhou Liu said: “The ongoing COVID-19 pandemic highlights the urgent need for a careful evaluation of the fate and control of this contagious virus in the environment.

“Environmental engineers like us are well-positioned to apply our expertise to address these needs with international collaborations to protect public health.”

A sewage leak led to a series of cases through aerosolization during a 2003 SARS outbreak in Hong Kong. Although there are no known cases of COVID-19 due to sewage leaks, the coronavirus is closely associated to the one that causes SARS, and infection through this channel is a possibility.

Coronavirus could also colonise biofilms that line drinking water systems, thereby aerosolized transmission becoming a possibility. This transmission pathway is believed to be a major exposure source to the bacteria that causes Legionnaire’s disease.

Most water treatment routines are believed to effectively kill or eliminate coronaviruses in drinking and wastewater. Methods such as oxidation with hypochlorous acid or peracetic acid, and inactivation by ultraviolet irradiation, and chlorine, are considered to kill coronaviruses.  The synergistic impact of beneficial microorganisms and the physical separation of suspended solids due to the use of membrane bioreactors in wastewater treatment plants, viruses concentrated in the sewage sludge get filtered out.

However, Liu and University of SalernoNaddeo director of the Sanitary Environmental Engineering Division and professor Vincenzo Naddeo believe that most of these methods have not been tested on effectiveness to filter out SARS-CoV-19 and other coronaviruses, and hence have called for additional research.

The researchers also recommended upgrading the existing water and wastewater treatment infrastructure in outbreak hot spots, which may receive coronavirus from hospitals, community clinics, and nursing homes. In such cases, for example, light-emitting, diode-based, ultraviolet point-of-use systems could disinfect water before it finds its way into the public treatment system.