SARS-CoV-2 an extensive monitoring of an Italian full-scale wastewater treatment plant

Wastewater-based epidemiology was adopted to monitor SARS-CoV-2 RNA in Caltanissetta (Sicily, Italy) full-scale wastewater treatment plant (WWTP). The sampling campaign lasted 288 days (from October 11, 2021 to July 26, 2022). Influent wastewater, effluent from the secondary clarifier, and disinfected effluent samples were monitored for SARS-CoV-2 RNA coupled with other conventional pollutants (total suspended solids – TSS, chemical oxygen demand – COD, biochemical oxygen demand – BOD, respectively, Escherichia coli). Results showed that the plant performs excellently in removing conventional pollutants (average removal of 94 %, 91 %, and 91 % for TSS, COD, and BOD, respectively). SARS-CoV-2 RNA was detected in all influent wastewater analyzed samples (average 1.1 × 105 copies genomic per litre – GC L−1). Within the biological process, a strong degradation of SARS-CoV-2 RNA was detected.High correlation between log-transformed SARS-CoV-2 in wastewater and the active cases was obtained (correlation coefficient of 0.85, p-value < 0.001when 14 days lag time was considered).