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

Sci Total Environ. 2020 Nov 1:741:140445. doi: 10.1016/j.scitotenv.2020.140445. Epub 2020 Jun 23.

Abstract

The outbreak of coronavirus infectious disease-2019 (COVID-19) pneumonia raises the concerns of effective deactivation of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in medical wastewater by disinfectants. In this study, we evaluated the presence of SARS-CoV-2 viral RNA in septic tanks of Wuchang Cabin Hospital and found a striking high level of (0.5-18.7) × 103 copies/L after disinfection with sodium hypochlorite. Embedded viruses in stool particles might be released in septic tanks, behaving as a secondary source of SARS-CoV-2 and potentially contributing to its spread through drainage pipelines. Current recommended disinfection strategy (free chlorine ≥0.5 mg/L after at least 30 min suggested by World Health Organization; free chlorine above 6.5 mg/L after 1.5-h contact by China Centers for Disease Control and Prevention) needs to be reevaluated to completely remove SARS-CoV-2 viral RNA in non-centralized disinfection system and effectively deactivate SARS-CoV-2. The effluents showed negative results for SARS-CoV-2 viral RNA when overdosed with sodium hypochlorite but had high a level of disinfection by-product residuals, possessing significant ecological risks.

Keywords: Cabin hospital; Disinfection; Disinfection by-products; Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).

MeSH terms

  • Betacoronavirus
  • COVID-19
  • China
  • Coronavirus Infections*
  • Disinfection*
  • Humans
  • Motor Vehicles
  • Pandemics*
  • Pneumonia, Viral*
  • RNA, Viral / analysis
  • SARS-CoV-2
  • Wastewater*

Substances

  • RNA, Viral
  • Waste Water