Program: science and technology projects related to coal mining and reclamation applied science projectsthis proposed research will evaluate the potential for economical and environmentally friendly…

Program: science and technology projects related to coal mining and reclamation applied science projectsthis proposed research will evaluate the potential for economical and environmentally friendly extraction of REE from illinois CMW streams. Rare earth elements (rees), defined here as the lanthanide elements plus yttrium and scandium, are strategically important for national security and emerging advanced technologies. Recent efforts in the U.S. Have concentrated towards developing of an economically competitive and sustainable domestic supply of REE. Specifically, nonconventional sources hosting elevated rees contents, such as coal mining wastes (CMW), have been explored as attractive sources for rees and other valuable metals. Our previous studies have demonstrated that CMW from the illinois basin often exhibit elevated rees contents, in the range that makes them excellent non-conventional REE sources. However, current methods to extract rees from CMW are not commercially viable, as they require the use of expensive chemical and metallurgic approaches. These processes also significantly increase the environmental footprint of rees extraction. The project propose is to develop a sustainable alternative for rees extraction from CMW through biotechnology approaches that leverage microbial metabolism. A biotechnology that not only increases the supply of rees, but one that also aids in remediating CMW thus addressing both the economic and environmental aspects associated with CMW.historically, microbial metabolisms have been successfully applied in biomining processes for copper, gold, andother trace metals. Microbes that specifically yield organic acids from their metabolism have also been shown torelease rees from phosphate minerals and coal refuse. While our current understanding of the key factors thatcontrol rees extraction by microbes is fundamentally lacking, phosphate and silicate solubilizing microbial biofilms enriched from CMW are resistant to the high associated metal content and thus provide an attractiveavenue for biotechnology development. Thus, the activities to be performed will target laboratory studies todetermine the CMW associated microbial community members with the highest rees extraction ability, the conditions necessary to promote their metabolism and growth, and how the technology can be designed to limit the production of toxic CMW and CMD waste products. The overarching goal of this project is to develop cost-effective, environmentally friendly rees extraction technologies that can be easily implemented by mine owners operators to not only yield a sellable commodity, but to also bioremediate their sites. The specific objectives of the proposed work are: 1) enrichment of biofilm forming, organic acid producing, and phosphate silicate solubilizing microbial communities from coal and GOB of varying sulfur content using carbohydrate stimulation 2) enhancement of biofilm mediated REE bioleaching processes from coal GOB using nutrient limitation as well as amendments such nucleic acid to promote matrix building and soluble electron shuttles to enhance redox reactions and 3) bioreactor optimization for maximum long-term REE recovery and limited pyrite oxidation sulfide release from coal GOB. The expected outcome of this unique project is to use the results to design biotechnologies that not only target optimal extraction of REE and other metals from CMW, but also support environmentally friendly remediation efforts of coal mining affected areas. This research has the potential to make major contributions to the field by: 1) identifying economically competitive and suitable domestic supplies of non-conventional REE resources, 2) designing biotechnologies for the successful extraction of REE from CMW, and 3) addressing key environmental issues of CMD remediation in the illinois basin. Intended beneficiaries of this project are the osmre and the coal mining state(s) and tribe(s).