Optimized process intensification through dynamic performance simulation and evaluation of treatment alternatives for a wastewater treatment plant in Toronto

Abstract

In this study, a comprehensive plant-wide model of the North Toronto Treatment Plant (NTTP) was developed, focusing on improving operational efficiency and capacity utilization. NTTP, with a rated capacity of 45 MLD, is currently operating at about 18 MLD with treatment processes including physical units (incorporating four primary settling tanks), chemical precipitation (for phosphorus removal using ferrous chloride), and biological processes (utilizing eight plug-flow conventional activated sludge (CAS) aeration tanks), and two sets of final clarifiers. Utilizing Biowin 6.2, the study constructed and calibrated a mechanistic model based on historical plant records and extensive sampling campaign data gathered from July to August 2022. The performance of various process configurations under different operational and seasonal conditions was evaluated. It was observed that the Ludzack-Ettinger (L-E) configuration demonstrated enhanced performance in terms of Environmental Compliance Approval (ECA) objectives and cost-efficiency compared to the CAS process. However, the L-E configuration posed challenges related to the final clarifier loading. The State Point Analysis (SPA) conducted within the study emphasized the effectiveness of the Membrane Aerated Bioreactor (MABR) in producing high-quality effluent, while also reducing the burden on the final clarifiers. This research provides a foundation for potential upgrades to NTTP, leveraging existing infrastructure to approach its full rated capacity while maintaining adherence to current ECA objectives.