INTEGRAZIONE DI DIGESTATO CHIARIFICATO COME FONTE DI AZOTO PER LA COLTIVAZIONE DI MICROALGHE

Abstract

A possible alternative to the common fertilizer for feeding microalgae is the liquid fraction of digestate coming from the plants of the anaerobic digestion plants. However, the inclusion of this nutrient as such leads to problems in the growth in culture due to the high turbidity. Therefore, it has been necessary to plan and test a process of sustainable clarification in order to remove most of the suspended solids that are present. By using the culture medium coming from the filtration phase of the alga, it is possible to thermally flocculate the solids of different size present in the digestate, thus making it less turbid. Testing the use of this solution in cultures at Nannochloropsis of different scale, it was observed that they have good growth rates and no perceptible inhibition due to the inclusion of the digestate.