Study the effect of gas sparger on gas holdup, and bubble dynamics such as bubble passage frequency, chord length distribution, and interfacial area in an air-water system in a bubble column PBR. Study the influence of gas sparger on hydrodynamics of PBR using real system. Study the impact of gas sparger for nutrients removal using wastewater as a medium. Lastly, study the synergistic effect and optimization of most influential parameters on CO2 fixation and nutrients removal