Mechanisms and application of microalgae on removing emerging contaminants from wastewater: A review

This study reviews the development of the ability of microalgae to remove emerging contaminants (ECs) from wastewater. Contaminant removal by microalgae-based systems (MBSs) includes biosorption, bioaccumulation, biodegradation, photolysis, hydrolysis, and volatilization. Usually, the existence of ECs can inhibit microalgae growth and reduce their removal ability. Therefore, three methods (acclimation, co-metabolism, and algal -bacterial consortia) are proposed in this paper to improve the removal performance of ECs by microalgae. Finally, due to the high removal performance of contaminants from wastewater by algal-bacterial consortia systems, three kinds of algal-bacterial consortia applications (algal-bacterial activated sludge, algal-bacterial biofilm reactor, and algal-bacterial constructed wetland system) are recommended in this paper. These appli-cations are promising for ECs removal. But most of them are still in their infancy, and limited research has been conducted on operational mechanisms and removal processes. Extra research is needed to clarify the applica-bility and cost-effectiveness of hybrid processes.