OPTIMASI PRODUKSI BIOMASSA MIKROALGA Scenedesmus dimorphus

Microalgae is a microphyta from eukaryotic unicellular has an average diameter of 20µm. Microalgae has potential as a raw material for biodiesel production as it contains a high amount of oil. Therefore, oil production from microalgae will rely on biomass concentration in the media. In this research, microalgae Scenedesmus dimorphus was cultivated in the glass reactor reactor then CO2 gas at certain rate was bubbled into the reactor. A response surface method was performed to determine the influence of nitrogen concentration in the form of KNO3, rate of CO2 gas and pH on biomass concentration. In addition, the optimal operating conditions were determined indicated by high content of biomass. A central composite design, with three independent variables and one response function was utilized to determine the influence of the input variables. The biomass concentration increased with increasing concentration of KNO3, rate of CO2 gas and medium pH before reaching the maximum point and then monotonically decreases. The optimal operating condition indicated by maximum biomass content was achieved with a KNO3 concentration of 1.98 g/L, a rate of CO2 gas of 1.07 mL/min and at a pH medium of 8.37.