Rhamnolipid-Based Remediation Technologies for Uranium and Rare Earth Element Contamination - Uranium mining in the U.S. Southwest has left thousands of legacy mining sites with uranium-contaminated soils.
These soils are polluting adjacent water and land resources that, in turn, pose serious threats to human and
environmental health. On the Navajo Nation alone, there are over 500 abandoned uranium mining sites and
12.8% of tested water sources exceed national drinking water standards. Uranium is also a challenge for modern
mining operations as it is often present as a contaminant in mineral processing activities targeting other metals.
In addition to uranium, rare earth elements (REE) are also often found as contaminants in coal and some hard-
rock mining operations. Due to volatile international markets and Chinese domination of market supply, there is
interest in developing alternative REE sources domestically due to the importance of REE to consumer
electronics, renewable energy technologies, and national defense. Despite expressed need from the mining
industry and federal regulators, technology that is both inexpensive and specific to uranium and REE is lacking.
Through Phase I research, GlycoSurf has demonstrated two technologies capable of the selective removal of
uranium and REE from complex mining solutions. The first is an ion flotation process wherein GlycoSurf’s
propriety surfactants complex with target metals in aerated treatment solutions. Metals are separated from the
bulk solutions as the metal-surfactant complex attaches to air bubbles rising to the solution surface for collection
as a metal-concentrate foam. The second technology is an adsorbent material generated by functionalizing solid
media with GlycoSurf’s proprietary surfactants. In this Phase II project, GlycoSurf’s objective is to demonstrate
the commercial potential of these technologies for large water treatment applications by: 1) up-scaling reactor
size, 2) developing treatment processes for continuous flow operations and testing, and 3) synthesizing more
cost-effective glycolipids. With the University of Arizona and Wayne State University as research partners,
GlycoSurf will accomplish this project through 4 aims. Currently, ion flotation has successfully been
demonstrated in small-volume batch operation. Aim 1 will develop and up-scale a continuous ion flotation
process using real-world metalliferous solutions supplied by BHP mining company and the U.S. Department of
Energy. Aim 2 will focus on up-scaling production of rhamnolipid-functionalized adsorbent materials and
developing a treatment process that will be challenged using real-world mining solutions. The need to reduce
materials costs of GlycoSurf surfactants will be the focus of Aim 3. In this aim, GlycoSurf will focus on cost
reductions through: 1) streamlining the synthesis process, 2) use of alternate starting materials, and 3) increasing
the scale of production to realize economy-of-scale savings. Aim 4 with examine the economic feasibility and
commercial potential of technology developments in this Phase II project using a techno-economic approach.
