Diplina Paul
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.
Virtual Poster Symposium 
Hi Diplina, Thanks for sharing your thorough review of Coronavirus in wastewater. I wish you the best as you move forward with your research.
Dave
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Hi Dave!
Thank you so much for your positive feedback.
This is just a humble attempt in consolidating the various pieces of information available in the literature that can help us to understand how the various environmental factors can impact the persistence and infectivity of coronavirus in aquatic environments. I believe these small steps can help us to better understand and prepare ourselves in current times.
-Diplina
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Hi Diplina – very interesting and timely presentation! Did any of the studies you reviewed quantify SARS-CoV2 in WWTPs or their effluent? Thanks for sharing!
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Hi Chelsea!
Thank you very much for your feedback.
The studies that I reviewed used various types of water matrices (tap water, wastewater, urine, etc). Regarding wastewater, it was collected from the WWTPs.
For example, Gundy et al. (2009; reference in the poster) had collected the wastewater after settling (i.e. primary effluent) from the Roger Road Wastewater Treatment Plant in Tucson, AZ. This primary effluent was then added to the coronavirus infected cells for their assay. I hope this answers this question.
-Diplina
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Hi Diplina ! It’s a very relevant presentation focusing on minute details. It brings a new perspective that the infection can spread through wastewater as well. As a conclusion what should be the most effective way to dispose virus infected wastewater?
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Hi Abhisek!
Thank you very much for your feedback.
Great question! The most effective way for disposal of virus-infected wastewater would depend on the path as well as the area of occurrence of the wastewater. For example, for wastewater from hotspots (hospitals, community clinics, etc) segregated or decentralized wastewater infrastructure is the most important thing. The proper use of disinfectants for the virus affected wastewater seems to adequately inactivate the virus.
For the treatment of potable water, ultraviolet-based oxidation processes as well as disinfection work efficiently. According to the new guidelines (released February 2020) of the U.S. Occupational Safety and Health Administration (OSHA), oxidation with free chlorine or peracetic acid and inactivation by ultraviolet irradiation, are expected to effectively protect wastewater workers, as well as the public, from coronavirus.
-Diplina
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