Design and performance of a low-cost microalgae culturing system for growing Chlorella sorokiniana on cooking cocoon wastewater

Nowadays, design and development of low-cost microalgae culturing system are a very hot topic in the field of algae cultivation in wastewater for biomass production and nutrient removal. Based on previous studies, a discarded plastic bottle and some cheap accessories were used to construct a microalgae culturing system in this work for decreasing the capital cost when Chlorella sorokiniana was cultivated in cooking cocoon wastewater (CCW). Results showed that this alga grew very well in the system under the culture conditions optimized in a previous study. During the 7-day microalgae cultivation, a maximum biomass concentration of 3.43 g L−1, a specific growth rate of 0.496 d−1, and a biomass productivity of 0.388 g L−1 d−1 were achieved, which suggested that the system was suitable for the cultivation of C. sorokiniana in CCW for biomass production. Moreover, nutrients in CCW were removed effectively by this alga. The removal efficiencies of ammonium (NH4+-N), total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) were 92.61, 78.50, 97.31, and 66.88%, respectively, by the end of 7-day microalgae cultivation. The harvested algal biomass contained 53.25% of proteins, 27.95% of lipids, 14.25% of carbohydrates, and 2.66% of pigments, indicating that the biomass could be used as a potential feedstock to produce a variety of bioproducts. Thus, it is concluded that the low-cost system constructed in this work was suitable for the cultivation of C. sorokiniana in CCW for biomass production and nutrient removal.