Effects of dilution ratio on nutrient removal, sedimentation efficiency, and lipid production by Scenedesmus obliquus in diluted cattle wastewater

Scenedesmus obliquus was cultured in diluted cattle wastewater, and the effects of dilution ratio on nutrient removal, sedimentation efficiency, and lipid production were investigated. Results showed the optimum dilution ratio was 1/5. Under this condition, the removal amounts of NH4+-N, Total nitrogen (TN), and Total phosphorus (TP) reached 17.7 +/- 0.7, 28.4 +/- 0.6, and 1.81 +/- 0.1 mg L-1, respectively. The corresponding sedimentation efficiency was higher than 75%, and lipid productivity was around 10.5 mg L-1 day(-1). The main fatty acid contains alpha-linolenic acid (C18:3) and palmitic acid (C16:0). This lipid composition was suitable for biodiesel production.