Bioethanol production from Scenedesmus in synthetic wastewater

In recent years, microalgae have been widely used in wastewater treatment and biofuel production. In this thesis study, Scenedesmus sp. microalgae species have been proposed to produce bioethanol. Bioethanol is one of the most popular types of biofuels due to its excellent properties. Scenedesmus sp. has been studied for its bioethanol and carbohydrate content potential, nitrogen and phosphorus removal characteristics, and resistance to contamination in dairy wastewater. Scenedesmus sp. was grown and cultured in synthetic dairy wastewater as part of this thesis investigation. The optical densities, biomass production rates, nitrogen and phosphate removals of Scenedesmus sp. were investigated by growing microalgae in TAP medium and dairy wastewater at initially PO4-P concentrations of 1.5 mg/L, 3 mg/L, 7.5 mg/L, 15 mg/L, and 30 mg/L, respectively. The highest biomass production rate has been found experimentally to be 132 mg/L/day at an initial PO4-P concentration of 7.5 mg/L. The maximum nitrogen removal effectiveness was determined experimentally at an initial PO4-P concentration of 7.5 mg/L. While the amount of nitrogen was 75.03 mg/L at the beginning, this value decreased to 1.78 mg/L after removal. The removal rate was calculated as 97.62%. Experimentally, the highest phosphorus removal efficiency was calculated as 96%at an initial PO4-P concentration of 1.5 mg/L. Carbohydrate at an initial PO4-P concentration of 7.5 mg/L was used to produce bioethanol, and the carbohydrate concentration was %24 and, the bioethanol content was 0.10 g ethanol/ g biomass. As a result, Scenedesmus sp. strain could be used for large-scale bioethanol production in synthetic dairy wastewater in the future.