Application of Biosorption for Rare Earth Recovery from Geothermal Brines

Abstract

The development of new methodologies that enable the economic and sustainable extraction of rare earth elements (REEs) from non-traditional feedstocks such as geofluids can help alleviate REE supply vulnerability and diversify the global supply chain. Using bioengineered rare earth-adsorbing bacteria, we have developed a biosorption technology that can be used for extracting rare earth elements from geofluids. Through selective adsorption of REEs on the cell surface, we observed effective REE recovery in a temperature-dependent manner. As a first step towards developing a modular, scalable extraction scheme, we examined continuous a flow-through system relying on immobilized microbes via biofilm formation or cell encapsulation. The initial performance with geofluids is presented and discussed. Besides REEs, the concept of biosorption using immobilized biomass can also be applied for effective recovery of other critical metals from geofluids.