Testing the Waste Based Biorefinery Concept: Pilot Scale Cultivation of Microalgal Species on Spent Anaerobic Digestate Fluids

Purpose A waste based biorefinery approach has been tested. Methods This has been investigated by culturing in a 800 L photobioreactor two autotrophic microalgae namelyNannochloropsis oceanicaandScenedesmus quadricaudautilising filtered spent anaerobic digestate fluids of N:P ratio 14.22 as substrate. Results Significant rates of bioremediation simultaneously with biomass and associated end product formation were achieved. Nitrogen and phosphorus of waste based media was decreased up to 90%. The biomass biochemical analysis of the microalgae when grown on the waste based formulated media demonstrated the comparable content of lipids and proteins with the species grown on f/2 media. Conclusions Theoretical biomethane potential generation, should the algal cultures be placed in an anaerobic digester, was calculated at 0.58 L CH4 g(-1)VS forN. oceanicaand 0.48 L CH4 g(-1)VS forS. quadricaudashowing comparable results with other studies of different source of biomass. Graphic