In this work, a cultivation system with daily recycling of the post-harvest culture broth was set up and performed in order to reuse the water and nutrients in pretreated anaerobically digested swine manure, which was used as media to cultivate Chlorella vulgaris (UTEX 2714) at different recycling ratios. Results showed that the alga grew well in the system with an accumulative algal biomass and productivity of 1.68–3.47 g/L and 234.1–532.2 mg/L/d, respectively, at the end of the cultivation. Additionally, chemical compositions in this alga varied with the change of recycling ratios, and the highest productivities of carbohydrate, protein and lipids (76.4, 257.2 and 183.7 mg/L/d, respectively) were obtained in the system with a recycling ratio of 1/4 or 1/6. Fatty acid profiles indicated that this alga could be used as a good-quality biodiesel feedstock with a biodiesel productivity of 9.65–40.1 mg/L/d.
Bibliographical noteFunding Information:
This manuscript was supported in part by the Qinglan Project of Jiangsu Province (2016), the Jiangsu Overseas Research and Training Program for University Prominent Young and Middle-aged Teachers and Presidents, and the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative Citizen Commission on Minnesota Resources (LCCMR) and University of Minnesota Center for Biorefining .
- Anaerobically digested swine manure
- Biomass productivity
- Chlorella vulgaris
- Daily recycling
- Nutrient removal