Simulation model of wastewater treatment plant with automatic control

The activated sludge process is widely used in wastewater treatment plants to reduce pollutant levels in contaminated wastewaters, which mainly come from industrial and municipal sector (Nelson et al. 2009). In the activated sludge process, there is a large variety of microorganisms capable of degrading organic matter, reducing nutrient content and transforming toxic components into harmless products. In recent decades, many authors have attempted to develop biological models to increase our understanding of the influence of process modifications on treatment process efficiency (Petersen et al. 2002). The Activated Sludge Model No. 1 (ASM1) presented by the IAWQ (International Association on Water Quality) is generally accepted as the state-of-the-art. The ASM1 describes the oxygen and nitrogen demand in microbial growth processes, including nitrification, denitrification and removal of organic matter mechanisms (Henze et al. 1987). The main objective of this study is to understand the secondary treatment of wastewater plants and its equipment operation by focusing on the biological relationships between species and the hydrodynamics that governs them, especially in transient cases. In this study, a coupled hydrodynamic and biological model that includes an automatic regulation faithful to reality has been designed, unlike common commercial models where the regulation is not included.