On the feasibility of Pseudochloris wilhelmii cultivation in sea-wastewater mixtures: Modeling and experiments

The possibility of cultivating the microalga Pseudochloris wilhelmii in low cost media obtained by mixing seawater and secondary wastewaters simulants is investigated for the first time in this work. The obtained results show that, under specific conditions, this microalga is not only capable of growing and producing good quality lipids but might also remove about 80%wt of nitrogen and 70%wt of phosphorus from the medium. Moreover, the obtained lipids would permit producing a good quality biodiesel which could be sold in the market. Experimental results are successfully interpreted by a novel mathematical model which simulates the temporal evolution of biomass and nutrients concentration as well as lipid content and pH by properly taking into account the effects of the main limiting factors, CO2 mass transfer phenomena and solution electro-neutrality. The proposed mathematical model might permit identifying the set of operating conditions which increases biomass and lipid productivity as well as macronutrients removal yields.