Cultivation of Chlorella sp. GD using piggery wastewater for biomass and lipid production

Abstract The development of a culture system for Chlorella sp. GD to efficiently produce biomass and oil for biodiesel production was investigated. Chlorella sp. GD was cultivated with 0%, 25%, 50%, 75% and 100% piggery wastewater (diluted by medium) at 300 μmol m −2  s −1 , a 2% CO 2 aeration rate of 0.2 vvm and 26 ± 1 °C; after a 10-day culture in batch cultures, the maximum specific growth rate and biomass productivity of the microalga obtained in 100% piggery wastewater were 0.839 d −1 and 0.681 g L −1  d −1 , respectively. The highest lipid content and lipid productivity were 29.3% and 0.155 g L −1  d −1 at 25% wastewater, respectively. In semi-continuous cultures, the biomass and lipid productivities with 25–75% wastewater ratios were greater than 0.852 and 0.128 g L −1  d −1 , respectively. These results show that Chlorella sp. GD grows efficiently in piggery wastewater, and that a stable growth performance was achieved for long-term microalgal cultivation in a semi-continuous culture.