Prediction of the sulfur driven autotrophic denitrification process via CFD-DEM approach

Sulfur driven autotrophic denitrification is an economic and efficient means to purify the nitrogenous wastewater. The long-term experimental study is quite time-consuming and expensive. In this work, a coupled computational fluid dynamics-discrete element method (CFD-DEM) is implemented to investigate the performance of long-term operating sulfur autotrophic denitrification process. The evolution of particle accumulation and nitrate removal efficiency in the packed bed reactors with different tube diameters and sulfur particle sizes are simulated. It is found that the NO-3-N removal rates for different tube diameters are close and a wider particle size distribution is shown in the slender reactor. The small particle bed shows a better NO-3-N removal efficiency.