I-Corps: Biological Extraction and Purification of Rare Earth Elements

Cornell University, Ithaca NY

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the potential development of an environmentally friendly, biology-based technology to extract and purify rare earth elements (REE). REE are elements from the periodic table consisting of the lanthanides elements as well as scandium and yttrium. They are essential ingredients in important modern technologies such as computers and catalysts, as well as many clean energy technologies such as windmills and electric cars. Currently, there is limited mining and purification of these critical minerals undertaken in the US. The proposed technology uses engineered bacteria to cleanly extract and purify REE from recycled and waste materials that are readily available in the US. Options for REE feedstocks include recycled electronics, coal ash, and various catalysts among other materials. This I-Corps project is based on the potential development of engineered bacteria capable of extracting and purifying rare earth elements (REE). The proposed technology uses the bacterium Gluoconobacter oxydans to produce an acidic biolixiviant capable of leaching REE into a solution from an REE-containing material. In addition, various strains of the bacteria Shewanella oneidensis are engineered to have binding sites on their membranes specific for a particular REE, which allows individual REEs to be adsorbed from a mixture. Individual REEs are then desorbed from the bacterial membranes to create a pure solution and precipitated from the solution as an oxide or carboxylate. Results at lab scale have shown that the engineered bacteria may produce a biolixiviant that will leach REE out of a feedstock into solution with a reasonably high efficiency and the relative affinity on the bacterial membrane for REE may be modified to enhance purification. The proposed technology may be used to extract and purify REE from waste such as coal ash as well as other feedstocks, providing a steady supply of REE. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.