(16−22) Many DBPs have been quantified since trihalomethanes (THMs) were first detected as DBPs in chlorinated drinking water in 1974. (11,14)Ĭhlorine-based disinfectants can react with natural organic matter (NOM), wastewater effluent organic matter (EfOM), and inorganic halide ions, resulting in the formation of several toxic disinfection byproducts (DBPs). (11,12) Among these, chlorine was widely used for the disinfection of domestic wastewater and drinking water in households, workplaces, public roads, and transports during the recent pandemic. (12,14) Conventional disinfectants include alcohol, formaldehyde, hydrogen peroxide, peroxyacetic acid, povidone–iodine, and chlorine-based disinfectants (chlorine, chloramine, and chlorine dioxide). Varying amounts of chemical disinfectants were used for sterilization in households, workplaces, public roads, and transport. According to the standards of GB-5749-2006 and GB-18918-2002, disinfectants used were elevated within the guidance ranges. In the regulation of GB-18918-2002, disinfections were used to inactivate the fecal Escherichia coli, it required that the amount of fecal Escherichia coli must be less than 1000/L in the disinfected domestic wastewater effluents according to the Level 1-A standard, and disinfectant doses were not recommended. In the regulation of GB-5749-2006, it required that the disinfection time of drinking water must be above 30 min, the free chlorine in finished water must be controlled in the range of 0.3–4.0 mg/L, and the residual chlorine in tap water must be above 0.05 mg/L. (10,11,14,15) During the SARS-CoV-2 pandemic in China, the disinfectant doses used for disinfection of drinking water and domestic wastewater were elevated within the guidance ranges according to the standards of Chinese GB-5749-2006 and GB-18918-2002, respectively. As a result, the dose of disinfectants in domestic wastewater and drinking water was elevated appropriately to curb the spread of SARS-CoV-2. (11−14)ĭisinfection was considered the most effective step to eliminate or deactivate the viruses, including SARS-CoV-2, and prevent transmission. (6,9,10) Nonetheless, effective disinfection of environmental matrices is crucial to minimize virus transmission through air, wastewater, and other possible routes. (8) Currently, there is no scientific evidence whether or not domestic wastewater and drinking water played an important role in the transmission of SARS-CoV-2.
suggested that the infectious viruses could be inactivated by the fluids present in the gastrointestinal tract, resulting in loss of infectivity. (6,7) In addition, high concentrations of viral RNA have also been detected in the stool samples. (4,5) A few studies have detected the presence of infectious SARS-CoV-2 virus in human feces, highlighting the possibility of stool transmission.
(3) Epidemiological studies have demonstrated that the SARS-CoV-2 virus undergoes human to human transmission through respiratory droplets. (1−3) Over 93.6 million confirmed cases and 2022405 deaths have been recorded globally as of Januand the confirmed SARS-CoV-2 cases continue to rise at an alarming rate. The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has rapidly spread to over 200 countries worldwide within months of its outbreak, causing unprecedented damage to human health and the economy. This study illustrates that the elevated use of disinfectants within the guidance ranges during water disinfection did not result in a significant increase in the concentration of DBPs. HAAs in wastewater effluents showed higher values of risk quotient for green algae. Out of the regulated DBPs, none of the wastewater effluents and tap water samples exceeded the corresponding maximum guideline values of chloroform (300 μg/L), THM4 (80 μg/L), NDMA (100 ng/L), and only 2 of 35 tap water samples (67.6 and 63.3 μg/L) exceeded the HAA5 (60 μg/L) safe limit. The results showed that the total concentration level of measured DBPs in wastewater effluents (78.3 μg/L) was higher than that in tap water (56.0 μg/L, p = 0.05), followed by surface water (8.0 μg/L, p 90%, respectively. In this study, the occurrence and distribution of five categories of DBPs, including six trihalomethanes (THMs), nine haloacetic acids (HAAs), two haloketones, nine nitrosamines, and nine aromatic halogenated DBPs, in domestic wastewater effluent, tap water, and surface water were investigated. Intensified efforts to curb transmission of the Severe Acute Respiratory Syndrome Coronavirus-2 might lead to an elevated concentration of disinfectants in domestic wastewater and drinking water in China, possibly resulting in the generation of numerous toxic disinfection byproducts (DBPs).
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