LAUSR

Chlorella vulgaris (C. vulgaris) was promising microalgae to simultaneously achieve biomass production, carbon dioxide (CO2) fixation, nutrients removal and proteins production especially under different conditions of CO2 gas and wastewaters. Results presented that maximal specific growth rate of C. vulgaris was 0.21-0.35 d-1 and 0.33-0.43 d-1 at 0.038% and 10% CO2 respectively, and corresponding maximal CO2 fixation rate was attended with 4.51-14.26 and 56.26-85.72 mg CO2·L-1·d-1. C. vulgaris showed good wastewater removal efficiency of nitrogen and phosphorus at 10% CO2 with 96.12%-99.61% removal rates. Nitrogen fixation amount achieved 41.86 mg L-1 when the initial NH4Cl concentration was set at 60 mg L-1 at 10% CO2. Improved total protein (25.01-365.49 mg) and amino acids (24.56-196.44 mg) contents of C. vulgaris biomass was observed with the increasing of added CO2 and ammonium concentrations. Moreover, the developed kinetic function of C. vulgaris growth depends on both phosphorus quota and nitrogen quota with correlation coefficient (R2) ranged from 0.68 to 0.97. Computed maximal consumed nutrients concentrations (ΔCmax) based on Logistic function are positively related to initial NH4+-N concentrations, which indicated that adding ammonium could stimulate the utilization of both phosphorus and nitrogen.