Search

• Microalgal growth and nutrient depletion kinetics were simulated in bubble column PBR. • CFD simulations highlight the dependence of microalgal growth on PBR hydrodynamics. • Microalgal productivity of 0.14 g L−1 d-1 achieved with 5.5 % human urine and 4% CO 2. • Phosphate and ammonium removal of 90 % and 84 % was attained in PBR respectively. • Contours of water velocity and turbulent energy gave insights on PBR hydrodynamics. Optimization of microalgae cultivation to reduce the associated costs is one of the major objectives in a biorefinery model. The present study optimized the microalgal cultivation using 4.5–8.5 % v/v of DHU (diluted human urine) as a cost-effective resource, in a bubble column photobioreactor (BCPBR) under real-time conditions. Media with 5.5 % DHU and 4% CO 2 showed maximal biomass productivity of 0.14 g L−1 day−1 with a final concentration of 1.06 g L−1. Phosphate and ammonium removal of 90.70 % and 84.10 % respectively was achieved. The biofixation of CO 2 obtained for 6 days, during the cultivation in 5.5 % DHU, by supplying 4% of CO 2 enriched air was 0.29 g L-1 d-1. Computational fluid dynamics (CFD) simulations were used to study the effects of velocity magnitude, shear stress, turbulent kinetic energy, and irradiance on the microalgal growth inside the BCPBR. The developed kinetic model predicted the biomass concentration and phosphate removal up to 98 % and 82 % accuracy respectively. Such studies would aid in comprehending the large scale commercial cultivation and thereby facilitate the application of microalgae in the future. [ABSTRACT FROM AUTHOR]