Modeling of microbial growth of Ralstonia eutropha in ‎biodegradation process of phenol in an airlift bioreactor with ‎concentric net draft ‎

According to the experimental observations, airlift reactor with net draft tube provided a ‎suitable ‎medium for microbial reactions, hence improved process efficiency and is a ‎recommended ‎bioreactor for wastewater bio-treatment. However, modeling and simulation ‎of biodegradation ‎process in this special bioreactor seems essential to proper design and ‎optimization of the ‎performance of the reactor. In this work, the biodegradation process of ‎phenol with Ralstonia ‎eutropha cells and microbial growth is simulated in a lab-scale airlift ‎reactor with net draft tube ‎using computational fluid dynamics (CFD). The k-ɛ model, as the most common model used for ‎description of turbulent flow, is used for the simulation of the present bubbly flow. Flow pathlines ‎in the riser and downcomer sections of the airlift reactor is simulated and the phenol concentration ‎variations and ‎biomass distribution in different inlet conditions were demonstrated by ‎simulated ‎concentrations contours. Good agreement was find between simulation and ‎experimental ‎results which validated the model and proved the accuracy of the simulation.‎