Trends and progress in Microalgae-based wastewater treatment technologies: A review

A transformative change is underway in wastewater treatment as the world aims at meeting Sustainable Development Goal 6 in 2030, and the conventional wastewater treatment processes have high energy consumption and greenhouse emissions. Microalgae-based wastewater treatment process has emerged as an innovative technology that can reach the demand for lowering energy consumption, mitigating climate change, and recycling resources. This review provides an overview of the basic theories of microalgae-based wastewater treatment processes, microalgae species commonly used, impact factors of microalgae cultivation, the conventional and hybrid microalgae-based wastewater treatment systems. Moreover, suggestions are proposed for further research and development.