North Carolina State University
Co-Authors: P. Kolar and S. G. Hall
The ongoing Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV-2) has triggered the coronavirus pandemic (also called COVID-19) that has claimed thousands of lives worldwide. This virus belonging to the Coronaviridae family is known to spread by human-to-human transmission via respiratory droplets. However, the presence of this virus in the fecal and anal swabs of infected patients has triggered the need for research in the probable fecal-oral pathway i.e. waterborne transmission and the consequent contagion to human health. Literature from the 2003 SARS epidemic research suggests the survivability of the coronavirus in hospital wastewater containing the fecal matter of infected individuals as well as in wastewater treatment plants (WWTPs). The various factors that impact the survivability of the coronavirus are temperature, solar or UV exposure, the presence of organic matter, oxidants like chlorine as well as adversary microorganisms. As coronavirus can persist in sewage for days, it does seem to appear as a possible threat if aerosolized (example: the leaking of a residential sewage pipe containing infected fecal discharge in Hong Kong during 2003 SARS epidemic). A few research articles studied the influence of temperature on the persistence of coronavirus and reported that the virus persisted in wastewater for 2 days at 20 ⁰C and for 14 days at 4 ⁰C. For stools, the survivability of the virus altered to 3 and 17 days at 20 ⁰C and 4 ⁰C, respectively. The occurrence of coronavirus in wastewater can be minimized by oxidation with chlorine, chlorine dioxide, peracetic acid as well as by UV inactivation. By far chlorine has been observed to be the most effective and economic option with a dosage of 10 mg/L for a minimum of 10 min or 20 mg/L for a minimum of 1 min. Membrane bioreactors in WWTPs are another viable option of coronavirus inactivation as it retains the suspended solids which are hosts of competitive microorganisms. However, the disinfection kinetics regarding inactivation is yet to be fully understood. Thus, further advanced research is needed to understand the fate and transport of the novel virus with respect to the urban water cycle so that effective strategies can be adopted to curb its effects on the public.