Experimental Protocol for Detecting SARS-CoV-2 in Screenings and Grit Samples of Wastewater Treatment Plants

Introduction: Although various liquid, solid, and gaseous streams of wastewater treatment plants (WWTPs) have been analyzed in many studies for the presence of SARS-CoV-2 RNA, no study was found to sample and detect SARS-CoV-2 RNA in screenings and grit samples separated from primary treatment units of WWTP. Hence, this study aims to provide an experimental protocol for sampling and extracting SARS-CoV-2 RNA from screenings and grits separated from WWTPs. Materials and Methods: First, sampling was conducted to extract SARS-CoV-2 RNA from screenings and grit samples. After sample processing and viral RNA extraction, SARS-CoV-2 RNA detection was performed by one-step reverse transcription quantitative polymerase chain reaction (RT-qPCR). Results: Based on the results, SARS-CoV-2 RNA was successfully extracted from screenings and grit samples of the studied WWTP with concentrations of (1.54 –3.9 × 104) and (0.8 – 2.3 × 104) genomic copies/L, respectively. Conclusion: Considering the successfully isolation and detection of SARS-CoV-2 viral RNA in solid phase samples of WWTP,  this method can be applied for extracting SARS-CoV-2 RNA and maybe other viruses from the screenings and grit samples of WWTPs in related studies.