عنوان مقاله [English]
Nowadays, with the industry development, a lot of waste is produced damaging the environment. Among wastewater treatment methods, anaerobic techniques have been highly regarded due to numerous advantages. In anaerobic systems, upflow anaerobic sludge blanket (UASB) reactor has many features. In this study using computational fluid dynamics techniques, three-phase reactor hydrodynamics in two and three dimensions have been studied. Initial results showed that the geometry of three-dimensional compared to its two-dimensional, more accurately predict hydrodynamics behavior in the process of wastewater treatment, so simulations were conducted based on a three-dimensional reactor. Interaction between phases was surveyed based on Eulerian model and for validation of the simulation model, the numerical results were compared with experimental data. COD removal and biogas production rates agree well with the results of the experiments. Evaluating numerical results show that the channel flow at heights of 20-40 cm occurs and presence of granules in the reactor causes an irregular pattern flow. Increasing residence time in the reactor lead to greater production of biogas and thus further reduction of the COD was occurred.