Cultivation of Scenedesmus obliquus in liquid hydrolysate from flash hydrolysis for nutrient recycling. (May 2016) - Barbera, Elena
Highlights: Hydrolysate from algal biomass flash hydrolysis has all the nutrients for growth. S. obliquus is able to uptake organic nitrogen and COD from the medium (mixotrophy). In continuous PBR inlet concentration and residence time affect nutrient yields. Inlet concentration should be optimized to avoid nutrients luxury up-take. Residence time should be optimized to obtain maximum productivity. Abstract: The production of biofuels from microalgae is associated with high demands of nutrients (nitrogen and phosphorus) required for growth. Recycling nutrients from the residual biomass is essential to obtain a sustainable production. In this work, the aqueous phase obtained from flash hydrolysis of Scenedesmus sp . was used as cultivation medium for a microalga of the same genus, to assess the feasibility of this technique for nutrient recycling purposes. Batch and continuous cultivations were carried out, to determine growth performances in this substrate compared to standard media, and verify if a stable biomass production could be obtained. In continuous experiments, the effect of hydrolysate inlet concentration and of residence time were assessed to optimize nutrient supply in relation to productivity. Results obtained show that nutrient recycling is feasible by treating biomass with flash hydrolysis, and Scenedesmus is capable of recycling large amounts of recovered nutrients.