The Reduction of SARS-CoV-2 RNA Concentration in the Presence of Sewer Biofilms

Shuxin Zhang; Elipsha Sharma; Ananda Tiwari; Yan Chen; Samendra P. Sherchan; Shuhong Gao; Xu Zhou; Jiahua Shi; Guangming Jiang

doi:10.3390/w15112132

Water (Jun 2023)

The Reduction of SARS-CoV-2 RNA Concentration in the Presence of Sewer Biofilms

Shuxin Zhang,
Elipsha Sharma,
Ananda Tiwari,
Yan Chen,
Samendra P. Sherchan,
Shuhong Gao,
Xu Zhou,
Jiahua Shi,
Guangming Jiang

Affiliations

Shuxin Zhang: School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong 2520, Australia
Elipsha Sharma: School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong 2520, Australia
Ananda Tiwari: Finnish Institute for Health and Welfare, 00271 Helsinki, Finland
Yan Chen: School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong 2520, Australia
Samendra P. Sherchan: Department of Environmental Health Sciences, Tulane University, New Orleans, LA 70118, USA
Shuhong Gao: State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
Xu Zhou: State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology, Shenzhen 518055, China
Jiahua Shi: Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong 2520, Australia
Guangming Jiang: School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong 2520, Australia

DOI: https://doi.org/10.3390/w15112132
Journal volume & issue: Vol. 15, no. 11
p. 2132

Abstract

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Wastewater surveillance has been widely used to track the prevalence of SARS-CoV-2 in communities. Although some studies have investigated the decay of SARS-CoV-2 RNA in wastewater, understanding about its fate during wastewater transport in real sewers is still limited. This study aims to assess the impact of sewer biofilms on the dynamics of SARS-CoV-2 RNA concentration in naturally contaminated real wastewater (raw influent wastewater without extra SARS-CoV-2 virus/gene seeding) using a simulated laboratory-scale sewer system. The results indicated that, with the sewer biofilms, a 90% concentration reduction of the SARS-CoV-2 RNA was observed within 2 h both in wastewater of gravity (GS, gravity-driven sewers) and rising main (RM, pressurized sewers) sewer reactors. In contrast, the 90% reduction time was 8–26 h in control reactors without biofilms. The concentration reduction of SARS-CoV-2 RNA in wastewater was significantly more in the presence of sewer biofilms. In addition, an accumulation of c.a. 260 and 110 genome copies/cm2 of the SARS-CoV-2 E gene was observed in the sewer biofilm samples from RM and GS reactors within 12 h, respectively. These results confirmed that the in-sewer concentration reduction of SARS-CoV-2 RNA in wastewater was likely caused by the partition to sewer biofilms. The need to investigate the in-sewer dynamic of SARS-CoV-2 RNA, such as the variation of RNA concentration in influent wastewater caused by biofilm attachment and detachment, was highlighted by the significantly enhanced reduction rate of SARS-CoV-2 RNA in wastewater of sewer biofilm reactors and the accumulation of SARS-CoV-2 RNA in sewer biofilms. Further research should be conducted to investigate the in-sewer transportation of SARS-CoV-2 and their RNA and evaluate the role of sewer biofilms in leading to underestimates of COVID-19 prevalence in communities.

Published in Water

ISSN: 2073-4441 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Hydraulic engineering; Technology: Environmental technology. Sanitary engineering: Water supply for domestic and industrial purposes
Website: http://www.mdpi.com/journal/water/

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