Current advances in microalgae-based bioremediation and other technologies for emerging contaminants treatment

Emerging contaminants (EC) have been detected in effluents and drinking water in concentrations that can harm to a variety of organisms. Therefore, several technologies are developed to treat these compounds, either for their complete removal or degradation in less toxic by-products. Some technologies applied to the treatment of EC, such as adsorption, advanced oxidative processes, membrane separation processes, and bioremediation through microalgal metabolism, were identified by thematic maps. In this review, we used a bibliometric software from >1000 articles. These manuscripts, in general, present removals from 0% to 100% for different ECs. This efficiency varies between treatment technologies and the contaminants' physical-chemical properties and their concentration and operational parameters. This review explored the bioremediation of EC through microalgae with greater emphasis. The main mechanisms of action of microalgae in the bioremediation of ECs are biodegradation bioadsorption, and bioaccumulation. Also, physicochemical properties and removal efficiencies of >50 emerging contaminants are presented. Although there are challenges related to the generation of more toxic by-products and economic and environmental viability, these can be minimized with advances in the development of treatment technologies and even through the integration of different techniques to make the treatment of contaminants emerging from environmental media more sustainable.