Covid 19 has been the most considerable situation in today’s society which has been a global pandemic spreading all over the world surpassing the traditional country borders and territories. The cause of the disease is the virus named SARS CoV-2 or else, Severe Acute Respiratory Syndrome Coronavirus-2. The human community is yet to find more about the effect of water on the way that this virus could spread and there are several research findings will be discussed here which have been confirmed by water scientists.

Hands should be washed every 20 minutes as one of the precautions against this disease as per the measures indicated by the WHO. The problem being raised since the induction of the global pandemic was how the RNA of the virus could be identified using laboratory experiments? What is the effectiveness of normal water treatment and wastewater treatment methods to remove SARS-CoV-2 from the water? Is there any possibility to contact with the viruses while a Covid-infected person is engaged in washing his/her hands? What is the rate of identification of Covid 19 patients in the vicinity of Covid treating hospitals and quarantine centres? These points would be addressed in this article.

SARS CoV-2 viruses are a family of single-stranded enveloped RNA viruses which are approximately 60-140 nm in diameter and are 82% similar to SARS Cov. This virus is detectable with RNA-based methods; hence it is the most possible method for culturing the virus is culture methods.

By using the research data Water scientists have discovered that the SARS-CoV-2 virus could be found in sewage for a few days or few weeks before Covid 19 patients were detected in a particular area. It is an early warning and sensitive enough to pick up the details of virus circulation. Wastewater research groups of New Zealand have confirmed this finding via two case studies done in New Zealand.

In the meantime, the effectiveness of removing SARS CoV-2 from water by using normal water and wastewater treatment methods should be considered a major concern which directly affects the lives of ordinary people as well as treatment plant workers. Evaluation of the water treatment unit process has concluded that the current treatment system adequately inactivates and removes viruses, which are more robust than SARS-CoV-2. The persistence of SARS CoV-2 and its amenability to chemical inactivation is similar to SARS CoV in terms of, being more sensitive than other viruses which cause intestinal diseases. Therefore, the researchers suggest that the most appropriate unit processes would be aeration and using PAA (Peracetic Acid) as a virus disinfectant. But aerosols that can be generated in the aeration process could make the SARS CoV-2 virus mix with air, thus dispersing the disease further. Hence, it is advised that the workers in those treatment plants should wear face masks and appropriate personal protection equipment (PPE) to minimize the health hazard.

In China and many other countries, SARS CoV-2 has been found to be viable in stool and urine samples collected from the patients infected by the virus. Hence, wastewater can be considered a major concern in the spread of the Cov-2 virus, and it should not be allowed in the wastewater or treated wastewater which can be a carrier of this dangerous virus. According to water scientists, to overcome this problem effective unit processes should be implemented in the treatment systems. Activated Sludge Process, which treats wastewater using aeration and a biological floc composed of bacteria could be, installed as a fundamental step in this regard, as the RNA of the SARS CoV-2 viruses could be degraded through this step. As the next step, a combination of normal disinfection processes could be used instead of one or two disinfection processes in the common wastewater treatment process. China Beijing Drainage Group collaborates with Tsinghua University on a research project to reveal the best fit disinfection process to enhance reliability, robustness, and flexibility for reclaimed water disinfection. They propose a disinfection system with a combination of ozonation, UV irradiation, and chlorination with Sodium hypochlorite. Six different operation schemes using Ozone and UV doses have been adjusted to achieve a high level of disinfection, whereas the residual chlorine concentration was relatively stable. The effluent of the combined disinfection practice achieved none of the SARS CoV-2 viruses and 99.99% inactivation of Fecal Coliform. Besides that, suggestions have been raised on the temperature of natural wastewater, which could inactivate the SARS-CoV-2 virus. Since the optimum temperature of this virus is around 4oC, another idea presented by the water scientists suggests the activities of bacteria that live in the wastewater and it is being suggested that this could be used to inactivate this virus present in the wastewater.

As mentioned earlier, amidst the current pandemic scenario, the main attention has been focused on the behaviour of water to spread the SARS-CoV-2 virus. Even though the data is not enough to reach a major conclusion on the situation, experiments are still going on different concerns at the laboratory scale and some of them have reached the ground level as well. When collecting the samples, foremost attention goes to the sewage veins of the neighbourhood of Covid 19 hospitals and quarantine centres. In a scholarly attitude, if a high concentration of SARS CoV-2 mix with water, the situation gets more critical causing an insistent spread.

However, more and more research data should be collected across the world to validate all of these ideas, creating new pathways for water scientists to affirm the established and novel findings of the SARS-CoV-2 virus. This would help everyone to conclude the effect of water on SARS-CoV-2 on a global scale. However, it should be specially noted that the management of wastewater during the Covid season is at high risk, though we take all necessary steps to minimize the risk. Moreover, the ability of the SARS-CoV-2 virus to survive against the common wastewater treatment methods and hospital wastewater treatment methods should not be regardless. Therefore, it is a high need to standardize the wastewater treatment methods to be on par with these kinds of health hazards. To put off this situation, the common practices should be conducted by complying with advanced hygienic and sanitization methods in particular bodies that engage in wastewater treatment. Moreover, combinations of different disinfection processes are suggested for effective water treatments within the urban areas where the Covid-19 hospitals and quarantine centres have been located. Workers who work in those places should obey the instructions of their governing bodies to adhere to the advanced health guidelines. If we are not implementing serious measures in eradicating the virus residues from the wastewater, most probably the wastewater could be the next SARS-CoV-2 transmission mode.

Saumya Amarakoon

B.Sc. (Hons’) in Water Science and Technology (UWU) M.Sc. in Environmental Engineering (AIT) – Reading

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