Biosorption as green technology for the recovery and separation of rare earth elements

Rare earth elements (REE) have great demand for sustainable energy and the high-end technology sector. The high similarity of REE owing to the nature of their electronic configurations increases the difficulty and costs of the development of chemical processes for their separation and recovery. In this way, the development of green technologies is highly relevant for replacing conventional unit operations of extractive metallurgy, viz. precipitation, liquid-liquid and solid-liquid extraction, and ion-exchange. Biosorption is a physicochemical and metabolically-independent biological process based on a variety of mechanisms including absorption, adsorption, ion-exchange, surface complexation and precipitation that represents a biotechnological cost-effective innovative way for the recovery of REE from aqueous solutions. This mini-review provides an overview and current scenario of biosorption technologies existing to recover REE, seeking to address the possibilities of using a green technology approach for wastewater treatment, as well as for the recovery of these high valued elements in the REE production chain.