Production of microalgae from olive mill wastewater

With olive mill wastewater (alpechin) used as a nutrient medium, the influence of the aeration level and the composition of the culture medium were analysed in relation to the concentration of alpechin and KNO3 added in a batch culture of the microalgae Chlorella pyrenoidosa and Scenedesmus obliquus. The pH and temperature of the culture were previously fixed at 6.5 and 30°C. As kinetic parameters, the maximum specific growth rate (μm) and the biomass productivity (Pmax) were determined. The biomass composition obtained was evaluated for chlorophyll and crude protein content as well as fatty-acid composition corresponding to the lipid fraction. To achieve a balanced biomass composition in terms of proteins and lipids, the most suitable conditions included an alpechin concentration of 10%, without the addition of nitrates and with an aeration level of 1 v/v min. Under these conditions, the μm values reached with both microalgae were around 0.03h−1.