Rapid Analysis of Effluent Water Quality in Activated Sludge Systems Using Computational Fluid Dynamics

摘要

Activated sludge systems are commonly used for treating sewage and industrial wastewater. The activated sludge process is a complex process involving physical, chemical and biological processes. A rapid evaluation of the effluent water quality in activated sludge systems would help engineers improve operation conditions and consequently bring economic benefits to wastewater treatment plant. In this study, computational fluid dynamics (CFD) was used to inform an activated sludge model (ASM1) for the chemical and biological processes, serving to provide a rapid evaluation of effluent water quality. The CFD-ASM1 was validated with the use of measured data, such as the effluent concentrations of chemical oxygen demand, ammonium, and nitrate, from a full-scale activated sludge tank. This study also studied the impacts of air flow rate and bubble size on air volume fraction distribution in the activated sludge tank using the CFD-ASM1. The model developed in this study can further serve as a tool to optimize operation conditions (e.g., air flow rate and bubble size) of activated sludge systems at a low cost.