Simulation-based evaluation of an existing wastewater treatment plant upgrade through MBR implementation using WEST

This thesis analyzes the effects of upgrading a conventional activated sludge wastewater treatment plant through the implementation of MBR (Membrane Bioreactor) technology. Although based on the same biological processes as conventional activated sludge, this technology integrates membrane separation, leading to an increase in purification performance. The study stems from the need to evaluate plant solutions capable of increasing hydraulic capacity, improving nitrogen compound removal, and ensuring compliance with future discharge limits required by evolving European regulations. These regulations will progressively complement the current Legislative Decree 152/2006 with the new Directive (EU) 2024/3019, which is characterized by more stringent requirements. The analysis was developed in two phases. As first, the main units of the biological process were sized using engineering calculation procedures, like the Metcalf & Eddy method. Instead, in the second phase the operation of both the existing plant and the MBR configuration was simulated using the WEST® software. The modeling was conducted using the ASM 1 kinetic model (Activated Sludge Model No.1), which describes the main biological processes responsible for the degradation of organic matter and nitrogen. The results obtained highlight how the adoption of MBR technology allows for an overall improvement in purification performance compared to the conventional configuration, while also ensuring greater operational flexibility and better compliance with future regulatory and operational demands.