Utilization of biogas as carbon dioxide provider for Spirulina platensis culture.

The purpose of this study was to study the effect of biogas utilization as CO 2 provider to S. platensis growth rate. Two scenarios of culture was conducted in this study i.e., Run 1 = culture was supplied using air continuously and Run 2 = culture was supplied intermittently using biogas and air. The results showed that growth rate of S. platensis in Run 1 and Run 2 was 0.21*10 -3 and 0.39*10 -3 /min, respectively. pH culture tend to decrease when supplied by biogas continuously. Kinetic model of S. platensis growth was modeled through modified Gompertz equation. The kinetic constants of Gompertz equation were obtained as follows: A (maximum value of OD680 reached), µ (maximum specific growth rate), λ (lag time) for Run 1 and Run 2 were 0.663; 0.459*10 -3 /min; 1454.9 min and 0.744; 0.588*10 -3 /min; 1024.5 min, respectively