Bioengineering of a Plant System to Remove Arsenic and Cadmium and Sustainably Harvest Rare Earth Elements (REEs) from Industrial Byproducts

Bioengineering of a Plant System to Remove Arsenic and Cadmium and Sustainably Harvest Rare Earth Elements (REEs) from Industrial Byproducts

Grand Rapids, Michigan

Bioengineering of a Plant System to Remove Arsenic and Cadmium and Sustainably Harvest Rare Earth Elements (REEs) from Fly Ash. Authors Ms. Edmaritz Hernandez Pagan - United States - North Carolina State University Dr. Colleen Doherty - United States - North Carolina State University Dr. Michael Kudenov - United States - North Carolina State University Dr. Kanjana Laosuntisuk - United States - North Carolina State University Abstract Fly ash is a fine powder-like residue from coal combustion. It can be utilized for industrial applications like concrete production or disposed of in landfills. Many regulations are involved in the use and disposal of fly ash safely. Fly ash typically contains high toxic heavy metal content that must be decreased before its utilization or disposal. It also contains rare earth elements (REEs). REEs are critical for modern electronics, green technologies, and defense systems. However, due to their dispersed nature in the earth’s crust, frequent co-occurrence with radioactive materials, and similar chemical properties, acquiring and purifying REEs is costly and environmentally damaging, restricting access to these metals. Most emerging technologies that harvest REEs from fly ash utilize harsh chemicals that compromise fly ash quality for concrete production. However, plants could remove toxic and high-value elements without significantly changing the fly ash composition since harsh chemicals are unnecessary. The objective of this investigation is to (1) characterize the growth of metal hyperaccumulator plants in metal-containing solutions and fly ash, (2) test the accumulation of arsenic, cadmium, and REE in aerial tissue, and (3) develop an imaging system to enable in vivo high-throughput detection of REE uptake in plants by exploiting the luminescent properties of these elements. We are implementing ICP-MS measurements to confirm the REE accumulation in the plant tissue generated through the imaging system. ICP-MS results show that one plant species hyperaccumulates arsenic and cadmium while another selectively accumulates specific REEs. Next, we’ll use the plant system to remove arsenic and cadmium, target REEs from fly ash, measure the remaining elements in the fly ash, and explore scalability possibilities. Through the ongoing exploration of this innovative approach, we aim to offer a sustainable and environmentally friendly solution to the challenges posed by fly ash and rare earth element extraction.