key: cord-1020028-8u6re7ok
authors: Bishai, Moumita
title: A comprehensive study of COVID-19 in wastewater: occurrence, surveillance, and viewpoints on its remedy
date: 2021-06-28
journal: Environmental and Health Management of Novel Coronavirus Disease (COVID-19 )
DOI: 10.1016/b978-0-323-85780-2.00015-9
sha: cdd63a5cf7f56ed31ae9f1dd012206bf299fa0f7
doc_id: 1020028
cord_uid: 8u6re7ok

The COVID-19 pandemic has had an adverse effect on human health, economy, and diverse environments. Besides the general transmission of the virus through air droplets and human-to-human contact; it is also transmitted while infecting the digestive system, which subsequently is defecated through the feces. Such fecal transmission can cause a major environmental distress, causing community transmission. This chapter attempts to investigate thoroughly the types of aquatic water bodies and addresses their role in the viral dissemination to combat SARS-CoV-2. It further enlightens the need for wastewater-based epidemiology (WBE) studies for surveillance as well as for early warning signal. The study could provide a comprehensive approach for designing effective strategies in the context of COVID-19 to counter the viral transmission and its deactivation. It also serves as a working paper for scholars and strategy regulators for planning and development of a new set-up from the global to the local level.

which needs to be utilized for assessing the effluent nature and for screening their performance with regard to numerous processes. Color is one additional important physical parameter to use when ruling on the features of water. For the treatment of wastewater, the question is not necessarily the appearance or color; the alternative suggested its use as an indicator to predict the wastewater condition. At the incipient the color of fluid of wastewater is light brownish-gray. The dissolved oxygen (DO) containing wastewater is normally gray in color. With the associated foul odor of wastewater, the color turns black, having no DO and thus depicted as septic in nature. The increase of travel time of the water in the pool and absence of oxygen turns the wastewater from gray to dark gray and ultimately to black. Turbidity is yet another measure. It is the degree where light absorption or scattering by suspended material in water takes place. Microbes, vegetable resources, detergents, and soaps, along with various other blending agents, contributed to turbidity. For the management of wastewater, measurements of turbidity are vital when ultraviolet (UV) irradiation is employed during the decontamination processes. Odors are generally produced by gases due to putrefaction of biological stuff or by constituents added to the wastewater. Also the temperature of wastewater found to be much higher compared to the supply of water. It occurs due to the mixing of warm aquatic wastes from human activities and industrial effluents released; nevertheless, significant amounts temperature fluctuations occurs due to infiltration or storm water flow. During the course of the day, there is variation in the flow rates of the wastewater. The phenomenon of variation is known as the diurnal flow variation. 6 

Generally, the aquatic waste released from different sectors depicted versatile chemical properties. Primarily they were divided into three categories: organic and inorganic matter, along with gases. In the medium strength wastewater, almost three-fourths of the suspended solids along with 40% of solids are filterable and are organic in nature. Proteins, carbohydrates, oil, and grease, along with detergents (surfactants) are included under the organic substances. About 15%e30% of organic matter are proteinaceous in nature. Urea with protein are the foremost nitrogenous sources in wastewater. The products released from the breakdown of carbohydrate molecules during anaerobic condition are alcohols and organic acids, as well as gases such as hydrogen sulfide and carbon dioxide. Production of huge amounts of organic acid influences the process of treatment by overstraining the protecting capability of the aquatic waste, which causes a drip in pH with the stoppage of biological motion. Categorization of grease includes oils and fats, along with waxes and other associated constituents present in aquatic waste. Presence of grease in wastewater is the main reason for obstruction of filters, spigots, and sand beds. Detergents are considered to be one of the largest organic molecules. They are soluble in water, and in the wastewater treatment plants they create foams.

Apart from these, there are several other inorganic characters for wastewater, which include determination of pH, alkaline nature, and nitrogenous properties of the aquatic system along with presence of chlorides, phosphates, sulfur, toxic inorganic compounds, and heavy metals, of which quantities vary depending on the type of wastewater. 6 

Organisms that are competent of contaminating or spreading the disease in humans and animals are known as pathogens. The wastewater comprises species of different bacteria, protozoa and parasitic insects (helminths). Viruses were also found, which cause severe infectious diseases. 6 Among the viruses, different types of coronaviruses including SARS-CoV-2 were also found in the wastewater. 7 The existence of these viruses in wastewater is governed by several physicochemical factors such as variations in temperature and pH; the presence of organic matter and oxidants; and plenty of hostile bacteria. 8 The details are discussed in the later part of the chapter.

There are numerous categories of wastewater, but keeping in mind the purview of the topic, the present chapter principally focuses only on different aspects of municipal and health care wastewaters.

Wastewater created due to "human activities in households" is termed as municipal wastewater. These wastes are discharged from residential areas, workplaces, and factories. They are originated from showers, toilets, and washing machines. 6 They are classified as blackwater and graywater ( Fig. 5.2 ). 1. Blackwater: In this case, dual modes of collection of effluents were considered. One is classic and the other one is selective collection. The former consists of entire aquatic collection and excretions discharged from toilets, whereas selective collections are usually from source-separating toilets and are composed of a fecal bin and urine diverter. Such selective collection allows compartmentalization of yellow water (urine and water from flush) with brown water (feces and toilet paper). 2. Graywater: Various emission sources were considered under this category. Effluent consists of kitchen sink and dishwasher discharge, and wash basins in bathrooms, baths, and showers. Tables 5.1 and 5.2 show the overall physical and chemical characteristics of untreated municipal wastewaters. In many developing countries, municipal wastewater generation has superseded the other types of wastewater generation and has become the major cause of water pollution and eutrophication.

The microbial load of municipal wastewater was found to be versatile in nature, having bacteria, alga, protozoa, and viruses. The pathogenic bacteria include fecal coliform, fecal Streptococci, and Clostridium perfingens, along with some anaerobic bacteria such as Clostridium sporogens, Bifidobacterium, and Methanogenic bacteria like Methanobacterium. Algal composition includes Chlorella phormidum, Ulothrix, etc. Different viruses such as Poliovirus, Rotavirus, etc. were found in sewage which acquires access through stools of patients. 6, 9 Presence of SARS-CoV-2 virus was also reported by Randazzo et al. 10 , Wu et al. 11 and many more. 

Hospital wastewater (HWW) usually generates from various types of medical care and its related activities. It comprises a variety of toxic substances, which include pharmaceutical products, radioisotopes, pathogens, solvents, and disinfectants. The characteristics of HWWs are comparable with municipal wastewater to some extent, but individually it also contains some other toxic pollutants. 12 In the waste released from hospitals, approximately 85% of the waste are equivalent with municipal waste and termed as nonhazardous. The remaining 15% are hazardous.

These wastes were classified as infectious waste, sharps, pathological waste, pharmaceutical and cytotoxic waste, chemical waste, and waste from radioactive sources, as described in Fig. 5 .3.

The wastes other than physical, chemical, biological, or radioactive are known as nonhazardous hospital waste.

Although different physical, chemical, and biological pollutants encompass hospital wastewater, the effluents for both conventional and nonconventional parameters were characterized and summarized in Table 5 .3.

The hospital effluents are sources of inorganic/organic loads and were demonstrated by their different concentration ranges of both macro-and micropollutants. 13 Gadolinium (Gd), platinum (Pt), and mercury (Hg) were found to be the main heavy metals in hospital runoffs. 14 Apart from these, Cd, Cu, Fe, Ni, Pb, Zn, and other heavy metals are similar in concentrations as reported in municipal discharge. 15 Various pollutants such as Gd, Hg, Pt, and pharmaceutical products along with acetaminophen, caffeine, ciprofloxacin, and gabapentin are released as hospital waste. 16e21 Along with the other microbes it also shows the presence of the SARS-CoV-2 virus. 22, 23 Hence, it could be predicted that when an infected individual's excreta containing pathogens gets flushed down the toilet or washed down the drain, it travels through the sewage system of a community. Exposure to such pathogens in a wastewater system could potentially cause serious health consequences in the community. Therefore, assessing the potentiality of infection and transmission of the disease through the wastewater system is desired.

Coronaviruses (CoVs) are a type of enteric virus that contain single-stranded positive RNA genome of the length of 27e32 Kb. 24 They belong to the order Nidovirales, family Coronaviridae, and subfamily Coronavirinae, and are the main cause of the present pandemic. 1 Spikelike projections on their exterior surface seen under the electron microscope are the glycoproteins, imitated as crownlike, hence the name coronavirus (CoV). 25 Coronavirinae are comprised of four genera, Alpha-, Beta-, Gamma-, and Delta-, among which infection in Homo sapiens was instigated by the first two (Alpha-and Beta-) host viruses. 26 Among them, a novel virus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) belongs to the beta-CoVs category. They cause the disease COVID-19 (CO means Corona, VI is Virus, D is disease, 19 is the year it was first discovered). 1 In December 2019, the virus spread from Wuhan, China, to the rest of the world. They showed high affinity for binding to the human angiotensinconverting enzyme 2 (ACE2) receptors. 1 Principally, SARS-CoV-2, along with ACE2 receptors, penetrate inside the host's system, where the proteins and the viral RNA are synthesized into multiple copies inside the cytoplasm to congregate the new virion gene. 27 Though the primary modes of the viral transmission are through respiratory droplets and direct or indirect contact, SARS-CoV-2 virus might get incorporated into the wastewater (municipal and hospital) through numerous sources, such as hand washing, sputum and vomiting, fecal waste, etc. 28 Hence, the potentiality of wastewater and its effect on SARS-CoV-2 was investigated for further understanding the epidemiology of COVID-19.

Existence of the virus in wastewater is highly influenced by subsequent factors, both intrinsic and extrinsic, depending on the wastewater or ecological environment:

• Structure of the virus: Enveloped viruses similar to coronavirus have shorter survival periods compared to nonenveloped viruses. 8 This was owing to the activity of detergents and proteolytic enzymes on the peripheral wall of the virus, which is lipid in nature. 29 • Composition of the wastewater: The component of the wastewater likewise plays a vital function in the persistence of viruses. The rapid inactivation of coronaviruses in wastewater is credited to the bacterial proteolytic enzymes and existence of chemicals that are antiviral in nature, along with predation of protozoa and metazoa in the wastewater. 29 • Temperature: Temperature has significant influence on the survival of coronaviruses in wastewater, similar to other microbes. The virus may survive longer in temperate or colder regions compared to tropical regions. With the increasing temperature, there is reduction in the persistence of the virus, which is attributed to the nucleic acid and protein denaturation, along with intensification of extracellular enzyme activity. 30,31 • pH: Significant modifications in the configuration of proteins was achieved by alteration of pH. A pH variation toward its isoelectric point causes precipitation; 32 the steadiness of SARS-CoV-2 in different pH values ranges from 3 to 10 at room temperature. 32 • Suspended solid: The suspended solids act as a shield to protect coronaviruses from inactivation. 8 Studies have shown the effect of suspended solids and organic matter on the survival of coronaviruses where it was reported that coronaviruses can survive longer in primary wastewater than in activated sludge wastewater. Likewise, Zhang et al. 23 reported the presence of organic matter in the patient's feces, which protect the SARS-CoV-2 virus from the disinfection process of medical wastewater. Thus, the persistence of coronaviruses in wastewater is intensely reliant on the properties of the individual aquatic medium.

reduction of pH values and the presence of urea. Conversely, saliva showed SARS-CoV-2 positivity and is responsible for the spread of COVID-19 with the help of air. Also, contamination of water occurs when infectious saliva is mistakenly touched by a clinically fit individual. Depending on excessive load of SARS-CoV-2 on saliva as well as in stool samples of COVID-19 patients, contaminated aquatic waste released from the health sector, isolation centers, and municipal areas and from the areas with cases of positive COVID-19 33 finally indicated transmission of SARS-CoV-2 through the fecal route. From feces, the virus gets diluted in toilet water and then in other municipal wastewater, including graywater, to the wider environment. Graywater is anticipated to not be ideal for SARS-CoV-2 transmission, though it contains high viral titers of body fluids. 34 The transport of the viral RNA through a complex sewage system compel them to be exposed to different chemicals and fluctuating temperatures. Diagrammatic route of transmission of the SARS-CoV-2 virus has been presented in Fig. 5 .4 35e37 On the basis of the decaying nature of the pathogens, that is, SARS-CoV-2, the degree of the health threat varies in the aquatic environment. There are possibilities to improve the control measures and wastewater treatment with the analysis of the decomposition of viral RNA. It has been found that the average duration of life of SARS-CoV-2 in the feces was up to 22 days, which was longer than that of SARS-CoV-1. It has also indicated that SARS-CoV-2 can survive longer in the fecal specimens than in respiratory (18 days) and serum (16 days). 38 Van Doremalen et al. 39 confirmed the variation of the SARS-CoV-2 half-life from 0.8 h on copper to 6.8 h on plastic.

Limited data are available on SARS-CoV-2 infection related to its occurrence and its molecular nature in feces and wastewater. Viral shedding in feces has been reported 23, 40, 41 and summarized in Table 5 .4.

After the feces is released into the wastewater, the presence of SARS-CoV-2 in wastewater endorses the fecal transmission route. 

In feces, the SARS-CoV-2 positive specimens were 44 out of 153 patients (29%). For the stool specimens, the mean series of threshold value was 31.4, which indicates a viral load of less than 2.6 Â 10 4 copies/mL. In nasal swabs the load was 1.4 Â 10 6 copies/mL. 92 The researchers tested on 10 pediatric SARS-CoV-2 infection cases highlighted that some patients were positive on rectal swabs even after their nasopharyngeal testing had become negative. 93 Fecal samples of nine hospitalized patients with COVID-19 during the course of the disease showed high viral RNA concentrations in initial samples, with a peak during the first week of symptoms. The viral content declined gradually. The viral load in feces varies in the range 10 3 e10 7 RNA copies/g feces. 94 The viral RNA in the stool was tested on the day of hospitalization. 15.3% of the patients detected the presence of SARS-CoV-2 RNA. In nine positive patients an average viral load of 104.7 copies/mL was found in the stool. 11

While investigating 74 fecal samples from patients, it was observed that over 50% of patients showed presence of SARS-CoV-2 RNA though the respiratory tract samples became negative 95

The feces of 73 hospitalized patients were examined for SARS-CoV-2 infection and it was evaluated that 53.4% of the patients showed positive results for viral RNA in stool. Additionally, greater than 20% of the patients having SARS-CoV-2 remain positive in feces, even after showing negative results in respiratory samples

Continued A comprehensive study of COVID-19 in wastewater

One of the most important studies was performed at the Ahmedabad wastewater treatment plant (WWTP) at Gujarat. Kumar et al. in 2020 reported 106 million liters per day wastewater, which receives effluent from the civil hospital treating COVID-19 patients. 42 Ahmed et al. 43 confirmed the presence of SARS-CoV-2 in untreated wastewater samples collected from pumping stations and wastewater treatment plants in Queensland, Australia.

Alternatively, samples collected from influent and secondary-treated wastewater were investigated for the existence of SARS-CoV-2 virus in Japan. 44 SARS-CoV-2 presence was confirmed in five secondary-treated wastewater samples with a load of 2.4 Â 10 3 copies/L. In contrast, the same was not detected in the influent wastewater samples. The authors explained the result on the basis of the limit of detection (LOD). The LOD value for the secondary-treated wastewater (1.4 Â 10 2 e2.5 Â 10 3 copies/L) was unusually lowered compared to influent (4.0 Â 10 3 e8.2 Â 10 4 copies/L). This is because the former (200 mL) had a lower filtration volume than the latter (5000 mL). Likewise, there are many more cases in different parts of the world that corroborate the fact of viral transmission from feces to wastewater 23, 45, 46 and treated wastewater 10, 47 in the recent worldwide outbreak, which was summarized in Table 5 .5.

Overall, from the above studies it could be anticipated that the routine wastewater monitoring can help to isolate a noninvasive warning sign to alert the community for new SARS-CoV-2 infections, as a large number of the viral carriers are asymptomatic and are present in a community which might intensify the epidemic abruptly. Table 5 .5 Details of occurrence of SARS-CoV-2 in wastewater environment in different countries.

Australia Concentrated SARS-CoV-2 RNA copies were classified using RT-qPCR. Two positive cases were detected within a six-day period from the wastewater treatment plant. The observed viral RNA copy numbers are then simulated using Monte Carlo model which estimated a median range of 171e1090 infected persons.

China Three hospitals wastewater samples were used for detection of SARS-CoV-2 viral RNA. It detected 255 copies/L of SARS-CoV-2 viral RNA in adjusting tank of first hospital wastewater. The second hospital wastewater was treated by a series of treatment steps in which SARS-CoV-2 viral RNA was detected in the adjusting tank (633 copies/L), but not detected in MBBR and sedimentation tank. In the third hospital treatment unit, SARS-CoV-2 viral RNA was detected in the range of 557e18,744 copies/L, only in septic tank where 800 mg/L sodium hypochlorite was used. It was not detected with 6700 mg/L of sodium hypochlorite.

Czech Republic

Concentrated SARS-CoV-2 RNA was detected in 11.6% of samples and more than 27.3% of WWTPs; in many places, SARS-CoV-2 was detected repeatedly.

Continued A comprehensive study of COVID-19 in wastewater 

Israel SARS-CoV-2 RNA was systematically detected in the influent of the primary settler suggesting that, the virus particles have a higher affinity for the sludge. However, in the digested sludge genetic material is not detected. The results further confirm the safety of the sludge after thermal treatment and anaerobic digestion. The combined treatment of thermal hydrolysis and anaerobic digestion also prevented the detection of SARS-CoV-2 in the sludge leaving the plant.

Istanbul Five samples out of seven from wastewater and all samples from manholes were tested positive. SARS-CoV-2 virus titers of manhole were higher than those of inlet WWTPs. Quantitative measurements of SARS-CoV-2 in wastewater were carried out using WBE which showed positive tested viral titer ranges from 1.17 Â 10 4 to 4.02 Â 10 4 /L. 

A comprehensive study of COVID-19 in wastewater

Because the virus is novel and has fatal outbreak, detection of SARS-CoV-2 in various environmental matrices is a major bottleneck at present. There is an urgency to identify highly specific and sensitive diagnostic measures for infected areas or people to avoid its further spread. It was observed that the testing rates for COVID-19 were quite low. 48, 49 Ever since the feces or urine showed early detection of the virus, 50 such sample testing from a community on a regular basis would minimize the spread of the virus. At present, various other diagnostic and detection methods are needed. For prompt, regular governing of viral outbreaks, WBE holds greater potential by regularly monitoring the variety and concentration of the virus in wastewater. The approach of WBE is thought to be effective for underdeveloped countries to scrutinize the predominance of the COVID-19 infectious spread in the community. Another advantage of WBE is that with the help of phylogenetic studies it supported the detection of variations in the viral strains. 51 Since many cases of SARS-CoV-2 infection are asymptomatic, the recognition of the inhabitants, which act as vectors to avert dissemination of the virus, is highly needed.

For accurate detection, the samples need to be processed for measuring SARS-CoV-2 appropriately. This involves preparation of the sample, concentration, RNA extraction, and finally genomic analysis. Proper biosafety protocols for processing the wastewater samples that may contain SARS-CoV-2 should be followed as recommended by CDC. 52 The process of concentration uses microbiological and molecular approaches prior to the detection process. 53 The recovery of virus by concentrating methods is way more challenging. There are various methods for concentration, such as PEG-based separation methods, applied electronegative membranes filtration methods, and applied ultrafiltration methods, 10,43,54e56 among them, concentration using PEG is the most prevalent method used for the COVID-19 WBE. 57 Followed by concentration is the method of detection or analysis. The most common methods are the reverse transcription-polymerase chain reaction (RT-PCR) and the reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). For example, Ahmed et al. 43 applied RT-qPCR to detect SARS-CoV-2 infected individuals in the catchment basin. Similar findings have been reported elsewhere. 4, 23, 44, 56 Although these PCR techniques have been applied as a yardstick for detection of SARS-CoV-2, they are unable to distinguish between infectious and inactive fractions. 58 Due to such inadequacies, another complementary method was adopted where direct absolute quantification of virus genome copy numbers in a sample without the necessity of external calibration can be performed. Digital PCR (dPCR) has recently been used for SARS-CoV-2 detection. 59 Owing to the rapid growth of confirmed cases of COVID-19, there is a serious need to develop a robust tool to address the challenge.

The biosensing technique has emerged with an interdisciplinary approach, which enables point-of-care diagnosis for swift and fast viral detection and prevents epidemics at an initial stage. In this context, Bhalla et al. 60 and Samson et al. 61 has reviewed the opportunities and technical challenges related to biosensors and analytical tools.

In a biosensor-based method, as reported, 62 a paper-based analytical device was constructed for the speedy determination of the pathogens. The small analytical tool has different functional areas with a wax printer that integrates all the processes required for nucleic acid testing into an inexpensive paper material. In a way, a paper-based device has the potential for the diagnosis of COVID-19 in aquatic waste in real-time for tracking the viral carriers in the community. 32, 63 Yet another technology, the CRISPR-based DETECTR, has been recognized to reconfigure SARS-CoV-2 detection within a few days. The assay was performed by simultaneous reverse transcription and isothermal amplification using loop-mediated amplification (RTeLAMP). The extracted RNA was taken in universal transport medium (UTM), followed by Cas12 detection of predefined coronavirus sequences, after which detection of the virus was confirmed by the cleavage of a reporter molecule. 64 The CRISPR-based DETECTR innovation is discovered to be very adaptable to reconfigure within a short time to distinguish SARS-CoV-2. The future improvement of different versatile microfluidic based cartridges and lyophilized reagents could empower purpose of care testing outside the indicative research facility. 64 For inactivating SARS-CoV-2 viral genome, photocatalytic nanoparticles (NPs) were also considered where titanium dioxide (TiO 2 ) showed photocatalytic properties under UV light. They remain dormant and are harmless in nature. If effective, the TiO 2 photocatalysis could be used for the deactivation of COVID-19. 65, 66 Electrospun nanofiber membranes were also found to be effective monitoring tools for screening disease causing pathogens. They play vital role in sieving intestinal Enterococci, E. coli, and coliform microorganisms. 67 These bioengineering-based nanofibers would especially increase the binding sites explicitness toward its objective, in this case COVID-19 viral RNA.

Numerous methods/devices have been applied for SARS-CoV-2 detection in different types of waste aquatic body as summarized in Fig. 5 .5, but the standardized protocols and authentication for such methods/devices are yet to be accessible in the public domain.

The emergence of SARS-CoV-2 has become a global health concern. from the perspective of virologists, the intestinal tropism of SARS-CoV-2 is extraordinary. As reported by an ongoing study, 68 the intestinal tropism demonstrated the hostile nature of SARS-CoV-2 compared to other viruses. Initially specific treatments were unavailable, until Chan et al. 69 and Yeo et al. 31 deciphered that there is a phylogenetic relationship between the genome of both SARS-CoV-2 and other bat-related SARS coronaviral genome. Also, the nucleotides of the spike protein show 78% similarity with the human SARS-CoV-1. 31, 69 With this assumption, scientists all over the world primarily hypothesized that SARS-CoV-2 would be reactive against various environmental aspects or disinfectants. Disinfectants typically act on the viral genome, capsid, or the protein layer, in a way destroying COVID-19. 7 Sporadic reports show the use of different disinfectants in this field. Initially, a study of hospital wastewater 23 indicated nonappearance of SARS-CoV-2 viral RNA in the influent, whereas the effluent was verified positive for the presence of viral RNA. Afterward, Zhang and his group investigated another study where three clinics of China were considered for the identification of SARS-CoV-2 virus by RT-qPCR. 45 The clinical study reported the presence of 255 copies/L of viral titers in the adjusting tank. The aquatic waste of the second hospital followed a series of treatment steps in the order of adjusting tankeseptic tank adjusting tankemoving bed biofilm reactor (MBBR)esedimentationedisinfection, in which SARS-CoV-2 viral RNA was detected in three units: the adjusting tank (633 copies/L), MBBR (not detected-505 copies/L), and sedimentation tank (not detected-2208 copies/L). In the third clinical treatment unit, it consists of two units (preliminary disinfection tank followed by septic tank), SARS-CoV-2 was detected in the range of 557e18,744 copies/L only in the septic tank when 800 mg/L sodium hypochlorite was used. However, no detection of SAR-CoV-2 was found; the sodium hypochloride concentration range was 6700 mg/L. Several similar studies were reviewed by researchers to further confirm the treatment of SARS-CoV using various disinfection treatments and its infectivity on inanimate surfaces. 41,70e72 Yet another disinfectant is hypochlorous acid (HOCl), which is a productive mediator against viruses for disrupting their genomic and proteomic mechanism. 73 Block and Rowan depicted the probable use of HOCl against SARS-CoV-2 virus disinfection. 74 Another disinfectant, ethanol, has been used for disrupting the cell wall of the virus as reported by. 71 They reported that 62%e71% ethanol along with 0.5% hydrogen peroxide, or 0.1% sodium hypochlorite (NaOCl) as surface disinfection rapidly reduces the infectivity of SARS-CoV-2 on different surfaces within 1 min exposure time. According to WHO recommendation, higher concentration of NaOCl or 70% ethyl alcohol are suitable for disinfecting surfaces. Therefore, the ethanol and sodium hypochlorite are highly recommended for killing SARS-CoV-2 and protecting water workers from COVID-19 infection. 75 The List N of the EPA has registered 431 commercial disinfectants which ascertain COVID-19 inactivation as of June 2020. Most of the products that follow the criteria chosen by EPA for its effectiveness against the removal of the virus possess some important component. 76 Despite the promising results from treatment using disinfectant as reported above, various disadvantages accompanied them. Hence, there is a need for further research for deactivating SARS-CoV-2 viral infection.

The COVID-19 also demonstrated a high sensitivity toward ozone treatment in indoor spaces. Ozone has the ability for the disruption of protein and the lipid of the spikes of the enveloped viruses, specifically fatty acids, cysteine, methionine, and tryptophan along with linoleic and oleic acid with N-glycopeptides present on the spikes of subunits 1 and 2 proteins. 77 With the gradual enhancement of ozone from 48.83 to 94.67 mg/m 3 , temperature from 13.17 to 19 C and a reduction of RH from 23.33% to 82.67% there is a decrease in the transmission of viral infections. 78 Ultraviolet C (UVeC) could be a promising alternative for SARS-CoV-2 strain inactivation as it damages the viral genome. 79, 80 Recently Inagaki and his coworker in 2020 have illustrated burgeoning deactivation method of COVID-19 using DUV-LED. 80 Another report revealed the inactivation of SARS-CoV-2 strain achieved with monochromatic UV-C (254 nm) irradiation, which is associated with multiple doses of illumination (3.7, 16.9, and 84.4 mJ/cm 2 ) in contrast to a sequence of different viral titers (0.05, 5, and 1000). 79 Using the technology, International Advanced Research Center for Powder Metallurgy and New Material (ARCI) India has put forward a positive effort to develop a device. The device contains three disinfection systems that execute various physical, thermal, and chemical processes for sterilization of a selected area and surfaces efficiently at different health care departments as well as public locales for combating the COVID-19 pandemic. The system has a UV-C-based trolley for disinfection, an air heater of honeycomb type, and a fogging system to provide effective inactivation against SARS-CoV-2. 81 Therefore, it could be predicted that in the near future, if used for wastewater treatment, it would be credible to provide benefit to the society in alleviating the viral outburst.

Recently, another group of researchers from US Department of Homeland Security provided the first data on the effect of simulated sunlight on the survival of SARS-CoV-2 suspended in simulated saliva or culture media and suggested that sunlight could directly influence the survival of the virus. 82 The study showed that under simulated sunlight, 90% of infectious virus gets inactivated in every 6.8 min in simulated saliva and in every 14.3 min in culture media. Further, confirmation is yet to be explored.

Beside this, various advanced oxidation processes (AOPs) including photocatalysis, ultrasonic process, and Fenton processes have also been effectively utilized in treating wastewater. 7 Different deactivation methods used for COVID-19 were represented in Fig. 5.6 . However, their use in wastewater treatment needs more momentum to gain robust solutions to meticulously eliminate the SARS-CoV-2 viral infection.

In a recent report, the municipal and hospital wastewater estimated the SARS-CoV-2 load ranges from 56.6 million to 11.3 billion per infected individuals in a single day. 4 Such huge viral loads need to be addressed. Hence, apart from eradicating the disease, various prevention-based approaches has been undertaken for self-protection and also for the protection of personnel working in different sectors. WHO in 2020 had provided standard precautionary measures and guidelines to be followed by the workers who were working in the viral-suspected areas 75,83 :

(1) Maintenance of social distancing between two persons of six feet (about two arm's length). Short-term laboratory biosafety guidelines, released by Centers for Disease Control and Prevention (CDC) put forward various instructions regarding management along with specimen dispensation associated with COVID-19. 84 The instructions summarize the facts that ➢ Standard precautions should be followed while handling COVIDrelated clinical specimens. ➢ Use of EPA-registered disinfectants, which claims SARS-CoV-2 removal, should be practiced. ➢ Proper procedures should be maintained for management of laboratory waste as instructed by the administrator. Although various effective measures were taken, the stigma in response to COVID-19 has put the life of health care workers and patients along with frontline workers in danger. 35, 85 Therefore, the following propaganda was suggested, which might instigate us for future research in this area: 1. The wastewater treatment of the community should be decentralized with the purpose that the release of the waste from the isolation centers, having infected patients residues, will not contaminate the nearby area. Hence, decentralization of a community might reduce the contamination of a neighboring region. 2. The immense populace needs large-scale testing, which is quite strenuous. Consequently timely viral detection of the feces needs to be attained, while scrutinizing the virus genome in the aquatic waste of a community wastewater for early detection of the virus in an individual. This communal testing found to be a better alternative for mitigating the viral explosion. 3. The competent authorities should adequately address the sanitation and improve the water quality required. In a way the aquatic contamination could be surpassed with the avoidance of unpredicted SARS-CoV-2 viral RNA transmission to an infected person. Also, other human enteric viruses and associated viruses which emanate from feces could be diagnosed and prevented. 4. For deactivating and eliminating SARS-CoV-2 viral genome and its related species from the feces present in aquatic waste, an economically cheap point-of-use device should be developed, which eventually will be available to the public. 5. An appropriate legal policy, laws, guidelines, and so forth need to be recommended to certify sufficient agreement for the release of wastewater into the atmosphere with proper treatment. Also, there is a need for various public awareness campaigns to tackle the stigma derived from the disease properly. 6. The government should implement a strategic plan for wastewater treatment plants at pilot scale, which could be beneficial in the long run. Also, there is a need for reforming the inconsistent health care system and setting proper guidelines for destroying such types of infectious disease outburst in the near future. The current snowballing spread of COVID-19 can be curtailed with a rising level of community empowerment, with healthy literacy to respond appropriately in the situation.

The occurrence of the COVID-19 pandemic reminds us that the life in the world is impulsive and challenging. At present, trivial knowledge existed on the potentiality of aquatic waste in the spread of the viral dissemination and its magnitude of infectivity. Studies are under progress on existence and deactivation of COVID-19 in the waste aquatic environment. The background information indicated the firmness of the genome and its analogy with SARS-CoV. Based on the contextual knowledge, the following research directions should be explored: 1. Governments should take responsibility to develop economically cheap wastewater-based epidemiologies for controlling the spread of the pandemic in developed and underdeveloped countries from the global to local level. 2. Though various researchers have shown interesting and positive outcomes addressing the water quality, viral propagation, inactivation mechanisms of SARS-CoV-2 under solar, and other disinfection, evidence regarding their removal still need to be deciphered. Studies on disinfection kinetics with reference to the dosage concentration, activity, etc. should be addressed to gain a comprehensive knowledge regarding the inactivation strategy. Also, environmental impacts must be studied to be considered for disinfectants and other deactivating techniques. 3. Concern associated with the health of wastewater treatment workers and COVID-19 frontline workers need to be attended with priority at regular intervals. Proper guidelines related to hygiene and other preventive measures should be augmented by policymakers and health administration. Also, clear strategies should be guaranteed for the support of infected health care workers to adequately cope with the disease. 4. Awareness programs for the public related to COVID-19 and its preventive practices need to be adopted to meet goals related to its elimination. For this, educational interventions might be considered. Ideally, the COVID-19 pandemic has taught us to work together. The integration and synchronization of various actions can contribute to this work on a global scale so that a happy future for all can be achieved.

Coronavirus in water environments: occurrence, persistence and concentration methods e a scoping review

Coronavirus disease (COVID-19) Situation report

Sewage surveillance for the presence of SARS-CoV-2 genome as a useful wastewater based epidemiology (WBE) tracking tool in India

Computational analysis of SARS-CoV-2/COVID-19 surveillance by wastewater-based epidemiology locally and globally: feasibility, economy, opportunities and challenges

Hospital wastewaters: characteristics, management, treatment and environmental risks

Handbook of water and wastewater treatment plant operations

SARS-CoV-2 in environmental perspective: occurrence, persistence, surveillance, inactivation and challenges

Survival of coronaviruses in water and wastewater

Physicalechemical treatment of water and wastewater

SARS-CoV-2 RNA in wastewater anticipated COVID-19 occurrence in a low prevalence area

Prolonged presence of SARS-CoV-2 viral RNA in faecal samples

Monitoring hospital wastewaters for their probable genotoxicity and mutagenicity

SARS-CoV-2 in hospital wastewater during outbreak of COVID-19: a review on detection, survival and disinfection technologies

Hospital effluents as a source of emerging pollutants: an overview of micropollutants and sustainable treatment options

Drugs in the environment: emission of drugs, diagnostic aids and disinfectants into wastewater by hospitals in relation to other sourcesea review

Characteristics of effluent wastewater in hospitals of Babol University of medical sciences

Detection of pharmaceuticals and phytochemicals together with their metabolites in hospital effluents in Japan, and their contribution to sewage treatment plant influents

Incidence of anticancer drugs in an aquatic urban system: from hospital effluents through urban wastewater to natural environment

Hospital wastewater treatment by membrane bioreactor: performance and efficiency for organic micropollutant elimination

Pharmaceutical contamination in residential, industrial, and agricultural waste streams: risk to aqueous environments in Taiwan

Hospital wastewaters-characteristics, management, treatment and environmental risks

Hospital effluent: investigation of the concentrations and distribution of pharmaceuticals and environment risk assessment

Potential spreading risks and disinfection challenges of medical wastewater by the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA in septic tanks of Fangcang Hospital

Origin and evolution of pathogenic coronaviruses

A review of coronavirus disease-2019 (COVID-19)

The species severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2

A novel coronavirus emerging in Chinadkey questions for impact assessment

SARS-CoV-2 in wastewater: state of the knowledge and research needs

Survivability, partitioning and recovery of enveloped viruses in untreated municipal wastewater

Coronaviruses in wastewater processes: source, fate and potential risks

Enteric involvement of coronaviruses: is faecaleoral transmission of SARS-CoV-2 possible?

Stability of SARS-CoV-2 in different environmental conditions

Saliva: potential diagnostic value and transmission of 2019-nCoV

Rethinking wastewater risks and monitoring in light of the COVID-19 pandemic

Potential fecal transmission of SARS-CoV-2: current evidence and implications for public health

COVID-19 faecal-oral transmission: are we asking the right questions?

COVID-19: the environmental implications of shedding SARS-CoV-2 in human faeces

Viral load dynamics and disease severity in patients infected with SARS-CoV-2 in Zhejiang province, China

Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1

Gastrointestinal symptoms of 95 cases with SARS-CoV-2 infection

Disinfection technology of hospital wastes and wastewater: suggestions for disinfection strategy during coronavirus disease 2019 (COVID-19) pandemic in China

The first proof of the capability of wastewater surveillance for COVID-19 in India through the detection of the genetic material of SARS-CoV-2

First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: a proof of concept for the wastewater surveillance of COVID-19 in the community

First environmental surveillance for the presence of SARS-CoV-2 RNA in wastewater and river water in Japan

SARS-CoV-2 spillover into hospital outdoor environments. MedRxiv; 2020b

Virus shedding patterns in nasopharyngeal and fecal specimens of COVID-19 patients

Time course quantitative detection of SARS-CoV-2 in Parisian wastewaters correlates with COVID-19 confirmed cases. medRxiv

Access to life saving medical resources for African countries: COVID-19 testing and response, ethics, and politics

Let Africa into the market for COVID-19 diagnostics

Early SARS-CoV-2 outbreak detection by sewagebased epidemiology

Novel wastewater surveillance strategy for early detection of coronavirus disease 2019 hotspots

Wastewater surveillance testing methods

Wastewater and public health: the potential of wastewater surveillance for monitoring COVID-19

Regressing SARS-CoV-2 sewage measurements onto COVID-19 burden in the population: a proof-of concept for quantitative environmental surveillance

First detection of SARS-COV-2 in untreated wastewaters in Italy

Presence of sarscoronavirus 2 RNA in sewage and correlation with reported COVID-19 prevalence in the early stage of the epidemic in The Netherlands

Primary concentration e the critical step in implementing the wastewater based epidemiology for the COVID-19 pandemic: A Mini-review

Current priority: coronavirus

Emerging technologies for the rapid detection of enteric viruses in the aquatic environment

Opportunities and challenges for biosensors and nanoscale analytical tools for pandemics: COVID-19

Biosensors: frontiers in rapid detection of COVID-19

Can a paper-based device trace COVID-19 sources with wastewater-based epidemiology?

Potential sensitivity of wastewater monitoring for SARS-CoV-2: comparison with norovirus cases

CRISPRe cas12-based detection of SARS-CoV-2

Nanotechnology-based disinfectants and sensors for SARS-CoV-2

Toward Nanotechnology-enabled approaches against the covid-19 pandemic

Wastewater-based epidemiology for early detection of viral outbreaks

Prolonged viral shedding in feces of pediatric patients with coronavirus disease 2019

Genomic characterization of the 2019 novel human-pathogenic coronavirus isolated from a patient with a typical pneumonia after visiting Wuhan

Biopolymeric nano/ microspheres for selective and reversible adsorption of coronaviruses

Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents

A review on presence, survival, disinfection/ removal methods of coronavirus in wastewater and progress of wastewater-based epidemiology

Concerns and strategies for wastewater treatment during COVID-19 pandemic to stop plausible transmission

Hypochlorous acidea review

COVID-19) advice for the public

N: disinfectants for use against SARS-CoV

Ozone: a potential oxidant for COVID-19 virus (SARS-CoV-2)

Back to normal: an old physics route to reduce SARS-CoV-2 transmission in indoor spaces

UV-C irradiation is highly effective in inactivating and inhibiting SARS-CoV-2 replication

Rapid inactivation of SARS-CoV-2 with deep-UV LED irradiation

Fight against COVIDss-19: ARCI's technologies for disinfection

Simulated sunlight rapidly inactivates SARS-CoV-2 on surfaces

Prediction for the spread of COVID-19 in India and effectiveness of preventive measures

Interim laboratory biosafety guidelines for handling and processing specimens associated with coronavirus disease 2019 (COVID-19)

Snowballing transmission of COVID-19 (SARS-CoV-2) through wastewater: any sustainable preventive measures to curtail the scourge in low-income countries?

Wastewater treatment: biological and chemical processes

Wastewater and its treatment techniques: an ample review

Municipal wastewater management using Vetiveria zizanioides planted in vertical flow constructed wetland

A residential blackwater and municipal waste treatment system e safety issues and risk management, organic recovery and biological treatment

Dynamics of active pharmaceutical ingredients loads in a swiss university hospital wastewaters and prediction of the related environmental risk for the aquatic ecosystems

Estimate of the metallic contamination of the urban effluents by the effluents of the Mohamed v hospital of Meknes

Characteristics of pediatric SARS-CoV-2 infection and potential evidence for persistent fecal viral shedding

Virological assessment of hospitalized patients with COVID-2019

Gastrointestinal manifestations of SARS-CoV-2 infection and virus load in fecal samples from the Hong Kong cohort and systematic review and meta-analysis

Evidence for gastrointestinal infection of SARS-CoV-2

Emerging coronaviruses: genome structure, replication, and pathogenesis

Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China

Preliminary study of SARS-CoV-2 occurrence in wastewater in the Czech Republic

First data-set on SARS-CoV-2 detection for Istanbul wastewaters in Turkey

Temporal detection and phylogenetic assessment of SARS-CoV-2 in municipal wastewater

Sewage/wastewater treatment technologies: a review

Molecular characterization of echovirus 30 associated outbreak of aseptic meningitis in Guangdong in 2012