Microalgae cultivation using nutrients in fish farm effluent for biodiesel production

Abstract

This article contributes to research on the composition of microalgae grown in fish farm wastewater (FFW), particularly for use in biodiesel production. In this research, Tetradesmus obliquus, Heterochlorella luteoviridis, and Chlamydomonas reinhardtii, cultivated in unmodified-and modified FFW, and the standard growth media, Tris-Acetate-Phosphate (TAP), were studied. The following parameters of the algae species were investigated: specific growth rate, biomass yield, biomass productivity, lipid content and carbohydrate content. Additionally, lipids and carbohydrate productivities were calculated, and the rate of CO2 uptake was determined. This study showed that the nutrients in FFW were suitable for algae biomass cultivation for biodiesel production. Chlamydomonas reinhardtii, in unmodified FFW, had the highest lipid and carbohydrate composition of 44.08% and 35.04%, respectively, and was most suited for biodiesel production as well as nutrient removal. The modified FFW only had the extra benefit of near-complete nutrient removal, but a comparable yield and biochemical composition with samples in unmodified FFW. A similar effect of CO2 concentration was observed in both the unmodified and modified FFW.