Chlorella sorokiniana as bioremediator of wastewater: Nutrient removal, biomass production, and potential profit

Microalgae growing using wastewater from agro-industry for both bioremediation and biomass production has high potential. Wastewater from industrial processing of instant coffee (WIC), dairy products (WDP), and cassava flour/starch (WCF) were used to grow Chlorella sorokiniana in five batches with different hydraulic retention times (HRT). For WIC and WCF, the best HRT for biomass production was at the 2nd cycle (52 d), with greater nitrogen (N), pHosphorus (P) and chemical oxygen demand (COD) removal efficiency. Overall, C. sorokiniana produced greater biomass from the 2nd cycle in WCF than in Bold's Basal Medium (BBM), WIC and WDP, which resulted in greater profit potential, standing out in the 4th cycle with HRT of 85 d. Thus, microalgae can contribute to phycoremediation of wastewater from the industrial processing of cassava, dairy, and instant coffee. In addition, they also produce biomass with profit potential, representing a sustainable and clean process. [Display omitted] •Chlorella sorokiniana removes nutrients and COD from wastewater.•Algal biomass is higher in wastewater from cassava than from the instant coffee.•Production of microalgae in wastewater has high potential for economic gains.•Microalgae production in wastewater is a clean and sustainable system.