Sludge Hygienisation—A Novel Technology for Urban Areas to Deal with Incursion of COVID-19 Viral Particles in Wastewater

Abstract

The ongoing pandemic of viral infections due to the novel coronavirus disease (COVID-19) is known to have affected about 8,240,000 people globally and approximately 3,67,000 people in India as of June 19, 2020. The pandemic being quite persistent in nature, timely planning for novel and adaptive interventions are required for dealing with it, with a view to detecting the early signs of infection, as well as, controlling the spread of the outbreak towards the uninfected population residing at comparatively safer zones. In general, the coronaviruses belong to a group of RNA viruses that are known to infect a wide range of hosts including humans, other mammals and birds, with the clinical courses in the infected hosts ranging from being asymptomatic to showing acute symptoms in the respiratory, digestive and genital organs. Although the SARS-CoV-2 (COVID-19) is reported to spread primarily through inter-personal physical contacts rather than the faecal-oral route, evidence of gastrointestinal symptoms caused by SARS-CoV-2 infections accompanied by the detection of viral RNA in the faeces of infected individuals, with high probability of their presence in wastewater samples, makes an important case for the thorough characterization and quantification of the pathogenic materials present in the municipal sludge generated in urban centres. This becomes even more important in the case of the metro cities and dense urban centres, where the chance of the medical wastes from the COVID hospital facilities coming into the municipal sewage stream is highly likely. However, the pathogens in the municipal sewage stream become concentrated in the sludge, providing an opportunity to treat the separated sludge from the wastewater stream using a technology of irradiation called ‘sludge hygienisation’ to curb the outbreak of the virus. The present work provides an assessment of the sludge hygienisation technology for its suitability as an option to eradicate the viral particles accumulated in the sludge samples from urban environments that are presumably infected through the faecal deposition, as well as, due to uncurbed release of untreated biomedical wastes. Such an intervention will provide suitable means to control rapid viral outbreak that might be attributed to the high volumetric flow rate of the municipal sewage. Investment in such novel interventions, given the current circumstances, will be important to contain present and future outbreaks, ensuring that the community healthcare systems are saved from being pushed to the limits owing to the increasing pressure on the infrastructure that arises from the rapidly growing number of infected individuals.