To evaluate the biomass production of consortium and selected commercial strains of algae, the experiments were conducted under three different levels of CO2 (ambient, 5% and 10%) in 1 L capacity flasks with 500 mL sterilized treated wastewater as growth medium in triplicates with an irradiance of 80 µmol m−2 s−1 and L:D cycle of 12:12 h for 10 days at 120 rpm in photo bioreactor. The CO2 was bubbled through the medium with air mixture at the rate of 150 mL min−1.