Increasing algal biofuel production using Nannocholropsis oculata cultivated with anaerobically and aerobically treated swine wastewater

For mass production of Nannocholropsis oculata, a cheap nutrition source such as swine wastewater is required. The use of a combination of anaerobically/aerobically treated swine wastewater (AnATSW) was compared to artificial 3 × f/2 medium in terms of algal growth rate and oil content. For microalgae cultured in 0–50% (v/v) AnATSW, a biomass of 0.94–3.22 g L−1 was reached in 5 days. For microalgae cultured in 3 × f/2 medium with vitamins, the lipid productivity was 0.122 g L−1 d−1 although its oil content reached 48.9%. Culturing N. oculata in 0–50% AnATSW resulted in an optimal lipid productivity of 0.035–0.177 g L−1 d−1. Only vitamins improved algal production of more oxidatively stable compositions of unsaturated oils. These oils were similar to the chemical structure of rapeseed oil based on analysis of the bis-allylic-position-equivalent value (30.64–46.13) and the iodine value (90.5–117.46). These oils were similar to coal based on the calculated low-heating-value of 17.6–22.9 MJ/kg.