Current and future perspectives of a microalgae based circular bioeconomy to manage industrial wastewater– A Systematic Review

Abstract

Post technological advancements and industrialisation, the recovery of resources by treating wastewater is gaining momentum. As the global population continues to grow, the need for water is becoming increasingly urgent. Therefore, the re‐utilisation of water is becoming an increasingly important factor in the preservation of life on this planet. Wastewater is classified according to its source of origin. When left untreated, the effluent causes several environmental hazards and poses health issues as they have higher concentrations of nutrients and toxic heavy metals. Currently, several conventional methods exist to treat and handle wastewater, but they generate secondary waste post‐treatment and are not sustainable. Microalgae‐based treatment of wastewater is highly sustainable, cost‐efficient and aligns with the concept of circular bioeconomy. The biological treatment of effluents using microalgae has several advantages. Approximately 1.83 kg of CO2 is sequestered per kg of the dry biomass during microalgae cultivation. Among all the sustainable alternatives, microalgae offer better biomass productivity by utilising a higher concentration of nutrients in wastewater. The wastewater‐grown microalgae have higher efficiency in producing commercially important secondary metabolites. This systematic review highlights the competence of microalgae in different wastewater sources and their industrial perspectives. This also gives an overview of the biproducts produced from microalgae‐based wastewater treatment.