Norovirus, Hepatitis a and SARS-CoV-2 Surveillance within Chilean Rural Wastewater Treatments Plants Based on Different Biological Treatment Typologies
34 Pages Posted: 1 Sep 2022
Abstract
During the COVID-19 pandemic, wastewater from WWTPs has become an interesting source of epidemiological surveillance. However, there is very little certainty about the influence of the treatment type on the removal of viral load. Therefore, the aim of this study was evaluating viral surveillance within wastewater treatments plants (WWTPs) based on different biological treatment typologies. Seasonal monitoring (autumn-winter and spring-summer) were carried out in 10 Chilean rural WWTPs based on activated sludge, aerated lagoons, bio-discs, constructed wetlands, vermifilters and mixed systems. SARS-CoV-2 and its variants (Delta, Lambda, Mu, Gamma, Omicrom), norovirus GI and GII (NoV GI and GII), and hepatitis A (HAV) were monitored in influents and effluents. Moreover, JC virus was used as virus process control. Results showed that SARS-CoV-2, NoV GI and GII were detected in influents at values between < 5 and 462, 0 to 28, and 0 to 75 GC/mL, respectively. HAV has not detected within the studied WWTPs. Therefore, monitored WWTPs removed these viruses at percentages between 0 and 100%. WWTPs based on mixed technologies (activated sludge and bio-discs) demonstrated be the most efficient removing SARS-CoV-2 (up to 98%) and NoV GI and GII (100 %). Meanwhile, bio-discs technologies reported be the least efficient in the viral removal by biofilm detachment which could adsorb viral aggregates. Indeed, correlation analysis established that solids, pH, and temperature are the most influential parameters in the viral removal from WWTPs. Viral surveillance within WWTPs is a valuable health surveillance tool, as we detected Omicron before the Chilean health authorities did. In addition, it allows evaluating the existence of various types of viruses that could potentially be a health risk if treated wastewater is recycled.
Note:
Funding Information: This work was supported under project USA1956_Dycit (project grant 092118VA_POSTDOC) “Study of the permanence, interaction, and treatment of emerging pollutants and pathogenic microorganisms from domestic wastewater” of the Universidad de Santiago de Chile. Moreover, Cristina A. Villamar-Ayala and Angela Plaza-Garrido acknowledge the financial support from Fondecyt (project grant 11190352), and Aldo Gaggero acknowledge the financial support from Fondecyt (project grant 1181656).
Declaration of Interests: None to declare.
Keywords: SARS-CoV-2, enteric viruses, wastewater rural domestic, biological treatment, physicochemical parameters.
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