AI-generated summary reviewed by our newsroom.<\/p>\n
Read our AI Policy.<\/a><\/p>\n \u200bToxic waste<\/a>, cancer and ecological degradation \u2014 these are just a few impacts of mining rare earth metals, which are essential for everything from smartphones to wind turbines.<\/p>\n Read more Milo Ventimiglia’s Pregnant Wife Shares Rare Glimpse Into Life as Parents<\/a><\/p>\n Researchers at North Carolina State University are working to change that. They\u2019re using plants to extract valuable metals from contaminated soil and water, a process known as phytomining<\/a>.<\/p>\n \u201cAt the current rate of use, we don\u2019t know where we\u2019re going to get enough rare earth elements to sustain the green energy transition,\u201d said Colleen Doherty, associate professor of molecular and structural biochemistry at NC State. \u201cAll this discussion about how electric cars aren\u2019t as environmentally friendly, that\u2019s because of the mining.\u201d<\/p>\n One of the worst impacts of mining is acid mine drainage<\/a>, or AMD. This occurs when a chemical reaction converts elements in exposed rocks into sulfuric acid, releasing both valuable and toxic metals, polluting waterways and harming wildlife.<\/p>\n Currently, mining produces between 17 and 27 billion gallons<\/a> of AMD each year \u2014 imagine the entire drinking supply of Lake Jordan<\/a> as a fishless pool of toxic sludge covered in an orange-brown film.<\/p>\n Even after treatment, AMD is left as a thick orange sludge that must be permanently stored in lined ponds.\u200b<\/p>\n This sludge still contains many valuable rare metals, but they exist in such low concentrations that traditional methods can\u2019t profitably extract them.<\/p>\n That\u2019s where the NC State researchers hope to make a difference. They aim to clean up the sludge and reduce costs by harnessing the power of plants.<\/p>\n \u201cThat\u2019s really the niche for phytomining,\u201d Doherty said. \u201cThere\u2019s value in the rare earth elements sitting around in an acid mine drainage sludge pond. That\u2019s a liability, so if we can use the plants to offset the cost, that\u2019s a better use of this technology.\u201d<\/p>\n Using plants to extract metal isn\u2019t new: research on using plants to mine nickel began in the 1990s<\/a>. However, expanding the process to less common metals has gained increasing attention over the last 20 years, and Doherty\u2019s team solved a key problem: when to harvest the plants.<\/p>\n In a new study published in Plant Direct<\/a>, the team took one step closer to sustainable mining by measuring the levels of rare-earth metals in pokeweed without destroying the plants. Pokeweed, a plant native to North Carolina, can absorb rare earth metals and<\/i> survive in toxic AMD.<\/p>\n Edmaritz Hern\u00e1ndez-Pag\u00e1n, a former NC State doctoral student, led these efforts in collaboration with Michael Kudenov, distinguished professor of electrical and computer engineering at NC State.<\/p>\n \u201cI\u2019ve always been interested in using nature to solve man-made problems, so I was excited to work on this project,\u201d Hern\u00e1ndez-Pag\u00e1n said. \u201cThe techniques that were already established were not very sustainable or accessible. The whole process is very complicated, and you have to destroy the plants.\u201d<\/p>\n Read more America\u2019s best president? N&O readers say who and why, from Washington to FDR<\/a><\/p>\n Doherty\u2019s team instead used a method known as fluorescence spectroscopy.<\/p>\n Instead of harvesting whole plants, researchers take a hole-punch from a single leaf, treat it with chemicals, and shine a light on it. By analyzing the intensity and duration of reflected light, they can cheaply and efficiently calculate how much metal is in the plant.<\/p>\n This not only allows researchers to harvest plants at optimal times, but also could help them breed the best-performing plants, making the entire process more efficient.<\/p>\n Yet, sustainability extracting metals from<\/i> the plants themselves remains a challenge.<\/p>\n \u201cYou cannot imagine a greener process than a plant gently plucking a metal from the ground,\u201d said Daniel Dailey, a Columbia University doctoral candidate and collaborator on the research. \u201cBut when you just go and turn around and burn it and convert it to carbon, then it kind of defeats the purpose.\u201d<\/p>\n Dailey\u2019s team is developing a process using bacteria to dissolve the plants and extract metals, with no burning or synthetic chemicals.<\/p>\n \u201cI think we\u2019re the first people … that have done this process biologically,\u201d Dailey said. \u201cInstead of just dumping some acid that was synthetically produced on it, we can use biology to get it out of the sludge and then to get it out of the plant.\u201d<\/p>\n Phytomining doesn\u2019t just offer an opportunity to increase sustainability; as the United States competes with China<\/a> for access to critical minerals, rare earth metals also play a strategic role.<\/p>\n \u201cRight now, China produces 80% of them; most of the world depends on China,\u201d Doherty said. \u201cAfter China withheld them from Japan after a political skirmish, everybody started scrambling to get their own sources.\u201d<\/p>\n Despite remaining hurdles, Doherty remains inspired by the possibility that this research can be further expanded and implemented.<\/p>\n \u201cThe pokeweed in my backyard right now grew two full feet in two months in a drought,\u201d Doherty said. \u201cThat\u2019s phenomenal. How many other plants are in our backyards that are doing these magical properties that we don\u2019t know anything about?\u201d<\/p>\n Hern\u00e1ndez-Pag\u00e1n also emphasized that phytomining isn\u2019t just a fantasy. U.S. based company Metaplant<\/a> began commercially phytomining nickel in northern Albania in 2024.<\/p>\n \u201cA lot of people think this is impossible,\u201d Hern\u00e1ndez-Pag\u00e1n said. \u201cI want people to know it\u2019s already happening, especially for things like nickel, and we\u2019re working really hard to make it ready for rare earth metals.\u201d<\/p>\n