S.M. Mousavi - Chemical Engineering Deapartment, TarbiatModares University, Tehran, Iran
Reza Heidari - Chemical Engineering Deapartment, TarbiatModares University, Tehran, Iran
Nader Bahrami - Chemical Engineering Department, Petroleum University of Technology, Abadan, Iran

Investigation on a reactor and its performance can be a valuable guidance prior to design phase. Additionally, the improvement in a bioreactor's performance is feasibe provided what happens in a reactor is thoroughly realized. Understanding of fluid hydrodynamics inside the recator reveals its characterisitcs. Time and cost are main factors affecting investigation of reactor's behavior. In present work, the behavior of a UASB reactor is investigated through the use of computational fluid dynamics (CFD). The simulation is done for a three-phase domain viz: solid, liquid and gas. the hydrodynamics observed in this simulation is used to predict the fluid flow and reaction progress. the produced biogas in the reactor led to expansion of sludge bed and affected gas bubble movement in the sludge bulk. The wasterwater flow pattern was studied and it was noticed that there was an interrelation between hydrodynamics parameters, biogas production, and COD reduction of wasterwater.

Chemical Oxygen Demand (COD), Computational Fluid Dynamic, UASB reactor, Wastewater, Biogas generation