Microbial iron mining: turning polluted soils into self-cleaning reactors

(Press-News.org) A team of scientists from the Chinese Academy of Sciences has introduced a groundbreaking nature-based solution to tackle global soil pollution—a crisis threatening ecosystems, agriculture, and human health. Their new research demonstrates that harnessing the natural power of microbes and iron minerals can remove toxic substances from soils efficiently and sustainably.

Soil pollution has reached alarming levels worldwide due to industrial activity, agricultural chemicals, and improper waste management. From heavy metals and persistent organic pollutants to microplastics and antibiotic resistance genes, these contaminants pose serious risks to food safety and the environment. Conventional cleanup methods are costly, energy-intensive, and often harm the natural structure of soils.

The scientists present "microbial iron mining," a process where soil microbes activate natural iron cycling. Microbes reduce and mobilize iron minerals, producing tiny iron nanoparticles that act as powerful traps for a variety of pollutants. These particles can capture and transform metals such as arsenic, lead, and mercury, as well as organic pollutants and even microplastics.

What makes this approach unique is its reliance on nature’s own strategies for self-purification. By adding agricultural residues like rice straw and carefully managing soil moisture, researchers can boost microbial iron activity and accelerate pollutant removal, all without disruptive excavation or aggressive chemicals. The resulting iron-rich minerals can be harvested for safe disposal or further resource recovery, minimizing the cost and environmental footprint.

Early studies in rice paddies and wetlands, landscapes naturally rich in iron and organic matter, show that microbial iron mining can immobilize toxic substances and transform persistent pollutants into less hazardous forms. This strategy even opens the door to recovering rare earth elements, which are critical for clean energy technologies.

While practical field-scale applications are still being developed, microbial iron mining represents a major leap forward in sustainable land management. By transforming polluted soils into self-cleaning biogeochemical reactors, this process supports the United Nations Sustainable Development Goals for clean water, safe food, and healthy ecosystems.

“Our work shows that soil can be engineered to clean itself through natural microbial and geochemical processes,” explains co-author Dong Zhu. “Microbial iron mining combines environmental harmony with practical resource recovery, offering hope for a cleaner, healthier future.”

 

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Journal reference: Zhang S, Zhu D. 2025. Microbial iron mining: a nature-based solution for pollution removal and resource recovery from contaminated soils. Environmental and Biogeochemical Processes 1: e006  https://www.maxapress.com/article/doi/10.48130/ebp-0025-0002  

 

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About the Journal:

Environmental and Biogeochemical Processes is a multidisciplinary platform for communicating advances in fundamental and applied research on the interactions and processes involving the cycling of elements and compounds between the biological, geological, and chemical components of the environment. 

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