Scientists are developing innovative methods inspired by the natural world to recover critical metals and minerals essential for the green energy transition. Instead of digging deeper into the earth, researchers are harnessing the power of specialized bacteria, fungi, and hyperaccumulating plants to harvest these valuable resources from the massive, trillion-dollar stockpiles of industrial and electronic waste currently languishing in landfills and wastewater ponds. This emerging field represents a pivotal shift from traditional extraction, offering a sustainable way to clean up contaminated environments while simultaneously building a circular economy for vital materials.
The economic and environmental stakes are enormous. Industrial mining sites alone hold an estimated $5.16 trillion worth of untapped resources trapped in wastewater. These materials, including lithium, cobalt, copper, and rare earth elements, are fundamental components for technologies like electric vehicle batteries, wind turbines, and advanced electronics. By deploying nature-based solutions, researchers aim to reduce the world’s reliance on conventional mining, which is often destructive to ecosystems and concentrated in geopolitically sensitive regions. These new bio-inspired technologies can transform hazardous waste into a valuable resource, simultaneously purifying water and creating new revenue streams from materials once discarded.
Microbial Miners Unlock Urban Ores
At the forefront of this resource revolution is biomining, a process that uses microorganisms to extract metals from waste. Certain bacteria and fungi naturally produce acidic or complexing agents that can dissolve and separate valuable metals from solid materials. This technique, known as bioleaching, is already used to a limited extent in traditional mining to process low-grade ores, accounting for the extraction of roughly 5% of the world’s gold and up to 15% of its copper. Now, scientists are adapting these microbial processes to tackle a much more complex and rapidly growing resource: electronic waste.
E-waste is often called an “urban mine” because of its high concentration of valuable metals. A single tonne of discarded mobile phones can contain up to 100 times more gold than a tonne of high-quality gold ore. Printed circuit boards are particularly rich, containing not only gold and silver but also base metals like copper and nickel, and platinum-group metals like palladium. Researchers are engineering specific bacterial species that can efficiently leach these metals from milled e-waste at neutral pH, avoiding the harsh acids and toxic cyanide solutions used in conventional hydrometallurgy. This approach dramatically reduces the generation of toxic waste streams and operates with significantly lower energy demands—up to 25 times lower than smelting or incineration.
Targeting High-Tech Components
The applications for biomining are expanding beyond precious metals. Researchers at institutions like the University of Edinburgh are pioneering methods to use bacteria to recover lithium and cobalt from spent electric vehicle batteries. At the University of California, Berkeley, one project is focused on developing a bacterial platform specifically to recover rare earth elements from a range of e-waste, from simple magnet shavings to complex, shredded mobile devices. These projects aim to create highly selective and environmentally friendly systems that can be scaled up or down, offering a flexibility that massive, fixed-infrastructure smelters cannot. Some companies in Europe and New Zealand have already begun deploying these technologies in mobile facilities to process e-waste locally.
Harnessing Plants to Harvest Metals
While microbes work on electronics, a different natural process is being adapted to clean contaminated land and recover resources from the soil itself. Phytoextraction, or phytomining, uses hyperaccumulator plants that have evolved the ability to absorb and tolerate high concentrations of metals and minerals in their tissues. These plants draw elements up through their roots and concentrate them in their shoots and leaves, which can then be harvested, dried, and processed to create a “bio-ore.”
This technique is particularly promising for recovering rare earth elements (REEs) from soils contaminated by mining activities or industrial pollution. REEs are often widely dispersed in soils, making conventional extraction uneconomical, but hyperaccumulators can concentrate them effectively. For example, studies have shown that Indian mustard (Brassica juncea) can be highly efficient at recovering gold, especially when the soil is treated with a chemical agent that makes the gold more soluble. Other research has identified reed canary grass (Phalaris arundinacea) as a top performer for accumulating a suite of REEs, including cerium, lanthanum, and neodymium.
Optimizing the Natural Process
The efficiency of phytoextraction depends heavily on environmental conditions and agricultural techniques. Researchers are actively studying how to optimize the process by using soil amendments like fertilizers and biochar, which can promote plant growth and increase the bioavailability of target metals. The acidity of the soil and water also plays a critical role. Some studies have shown that treating water with citric acid can enhance a plant’s uptake of REEs through its root system. By fine-tuning these parameters, scientists aim to develop scalable phytomining operations that can be deployed at former mine sites and other contaminated areas, turning environmental liabilities into valuable assets.
Tapping Trillions in Liquid Assets
Perhaps the largest and least-tapped reservoir of critical minerals is dissolved in industrial wastewater. Scientists at The Australian National University (ANU) are developing a filtration system that mimics the advanced separation mechanisms evolved by plants over billions of years. This technology, known as Bioderived Element Resource Separation Technology (BERST), uses bioengineered proteins programmed to selectively capture and separate high-purity minerals from mining wastewater. These proteins act as highly specialized filters, targeting valuable resources like copper and lithium while allowing clean water to pass through.
This approach offers a dual benefit: it recovers critical resources needed for the green economy and provides a novel solution to bolster global water security. Plants have perfected the ability to compartmentalize toxins while extracting the specific nutrients they need, and BERST adapts this natural blueprint into a transportable technology that can be deployed at any mine site. The system could dramatically cut the multi-billion-dollar annual costs of mine closure and rehabilitation while opening up entirely new revenue streams for mining companies.
The New Economics of Green Resources
The drive toward a circular economy for critical minerals is fueled by intense global demand. As nations transition to renewable energy and advanced technologies, the need for materials like lithium, cobalt, and REEs has skyrocketed, straining supply chains and increasing competition for finite resources. Nature-inspired recovery methods offer a path to bolster domestic supplies, reducing reliance on foreign imports that often come with significant environmental and ethical baggage. By transforming industrial byproducts and legacy wastes like coal ash and mining tailings into valuable feedstocks, this approach enhances energy security and mitigates the health hazards posed by stockpiled waste.
This model is already proving successful in some parts of the world. Taiwan, for instance, is a leader in “urban mining,” with companies excelling at extracting and refining high-purity gold and copper from discarded electronics. By treating its cities as rich resource mines, Taiwan has reduced its dependence on traditional mining and built a strong economic foundation on recovered materials. This strategic shift demonstrates that managing e-waste is not just an environmental obligation but a significant economic opportunity.
