Imprints of Lockdown and Treatment Processes on the Wastewater Surveillance of SARS-CoV-2: A Curious Case of Fourteen Plants in Northern India

Vaibhav Srivastava,Vinay Kumar Tyagi,Sonika Saxena,Manish Kumar,Sudipti Arora,Aditi Nag,Akhilendra Bhushan Gupta,Absar Ahmed Kazmi,Jasmine Sethi,Devanshi Sutaria,Ankur Rajpal,Satya Brat Tiwari,Jayana Rajvanshi,Sandeep Kumar Shrivastava

doi:10.3390/w13162265

Abstract

The present study investigated the detection of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) genomes at each treatment stage of 14 aerobic wastewater treatment plants (WWTPs) serving the major municipalities in two states of Rajasthan and Uttarakhand in Northern India. The untreated, primary, secondary and tertiary treated wastewater samples were collected over a time frame ranging from under-lockdown to post-lockdown conditions. The results showed that SARS-CoV-2 RNA was detected in 13 out of 40 wastewater samples in Jaipur district, Rajasthan and in 5 out of 14 wastewater samples in the Haridwar District, Uttarakhand with the E gene predominantly observed as compared to the N and RdRp target genes in later time-points of sampling. The Ct values of genes present in wastewater samples were correlated with the incidence of patient and community cases of COVID-19. This study further indicates that the viral RNA could be detected after the primary treatment but was not present in secondary or tertiary treated samples. This study implies that aerobic biological wastewater treatment systems such as moving bed biofilm reactor (MBBR) technology and sequencing batch reactor (SBR) are effective in virus removal from the wastewater. This work might present a new indication that there is little to no risk in relation to SARS-CoV-2 while reusing the treated wastewater for non-potable applications. In contrast, untreated wastewater might present a potential route of viral transmission through WWTPs to sanitation workers and the public. However, there is a need to investigate the survival and infection rates of SARS-CoV-2 in wastewater.

Highlights

The coronavirus disease (COVID-19) caused by Severe Acute Respiratory SyndromeCoronavirus 2 (SARS-CoV-2) emerged as a worldwide public health emergency within a few months of its outbreak in Wuhan, China in 2019
Further investigation into the role of biofilm is much needed, as the aerobic biological wastewater treatment process investigated in this study seems to be more efficient in the decay of viral RNA than the anaerobic UASB system, in which the decay is completed only after the post-secondary treatment aeration stage [20].The findings from the present study indicate that secondary aerobic biological wastewater treatment plants (WWTP) contribute to reducing the virus concentration due to the adverse environmental conditions to make the water fit for reuse
The results suggest that all three treatment processes successfully reduced/removed the virus genetic load in wastewater samples; the performance of moving bed biofilm reactor (MBBR) was found to be higher than that of the sequencing batch reactor (SBR) and Activated Sludge Process (ASP) treatment processes

Summary

Introduction

The coronavirus disease (COVID-19) caused by Severe Acute Respiratory Syndrome. Coronavirus 2 (SARS-CoV-2) emerged as a worldwide public health emergency within a few months of its outbreak in Wuhan, China in 2019. The extent of the pandemic COVID-19 is widespread and is currently confirmed to be present in more than 213 countries/regions worldwide [1,2]. SARS-CoV-2 spreads through air droplets and physical contact [3]. It is challenging to check and control the disease spread in developing countries like. India because of the dense population [3] These challenges are evidenced by an initial gradual increase in infection rates during the lockdown, followed by a sharp increase in the number of positive cases alongside the lifting of lockdown restrictions in India.

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