Wastewater-Based Epidemiology for SARS-CoV-2 in Northern Italy: A Spatiotemporal Model.

The study investigated the application of Wastewater-Based Epidemiology (WBE) as a tool for monitoring the SARS-CoV-2 prevalence in a city in northern Italy from October 2021 to May 2023. Based on a previously used deterministic model, this study proposed a variation to account for the population characteristics and virus biodegradation in the sewer network. The model calculated virus loads and corresponding COVID-19 cases over time in different areas of the city and was validated using healthcare data while considering viral mutations, vaccinations, and testing variability. The correlation between the predicted and reported cases was high across the three waves that occurred during the period considered, demonstrating the ability of the model to predict the relevant fluctuations in the number of cases. The population characteristics did not substantially influence the predicted and reported infection rates. Conversely, biodegradation significantly reduced the virus load reaching the wastewater treatment plant, resulting in a 30% reduction in the total virus load produced in the study area. This approach can be applied to compare the virus load values across cities with different population demographics and sewer network structures, improving the comparability of the WBE data for effective surveillance and intervention strategies.

Comparative Preliminary Evaluation of 2 In-stream Water Treatment Technologies for the Agricultural Reuse of Drainage Water in the Nile Delta.

In the Nile Delta, a complex network of canals collects drainage water from surface-irrigated fields but also from municipal wastewater. The goal of this work was to assess the technical, environmental, and financial feasibility of the upgrade of a drainage canal (DC) into either an in-stream constructed wetland (ICW) or a canalized facultative lagoon (CFL), in order to produce a water reusable in agriculture according to Egyptian law. The model-based design of the proposed technologies was derived from field experimental data for the ICW and laboratory data for the CFL. Both technologies, integrated by a sedimentation pond and a disinfection canal, led to the attainment of the water quality standards imposed by Egyptian Law 92/2013 for the reuse of drainage water. The life cycle assessment indicated that the upgrade of an existing DC to either an ICW or a CFL results in an extremely small environmental burden, ≤0.3% of that of a traditional activated sludge process. The cost-benefit analysis (CBA) was based on the assumptions that 1) farmers currently irrigate a nonfood crop (cotton) with the low-quality drainage water present in the DC, and 2) thanks to the upgrade to a ICW or CFL, farmers will irrigate a food crop characterized by a higher market price (rice). The CBA indicated that the DC upgrade to an ICW represents an attractive investment because it leads to a financial rate of return >10% over a wide range of cotton market prices. Conversely, the upgrade to a CFL is less attractive due to high investment costs. In conclusion, the upgrade of DCs to ICWs appears a promising option for the treatment of drainage canal water in the Nile Delta, thanks to the high pollutant removal performances, low cost, and negligible environmental burden. Integr Environ Assess Manag 2020;16:920-933. © 2020 SETAC.