Engineered Diatomaceous Earth Shows Promise for Removing Industrial Pollutants from Water

Europe’s water bodies are facing a severe crisis. More than half of them are heavily polluted, primarily with chemicals from industrial and agricultural activities. This pollution poses a serious threat to aquatic ecosystems and the quality of water available for human use. Every day, industries across Europe use up to 70,000 different chemicals, many of which end up in rivers, lakes, and groundwater, contaminating water supplies. Researchers at the University of Duisburg-Essen have recently developed a promising solution to this growing problem: using the fossil remains of diatoms, a type of algae, to purify polluted water.

The Scope of Water Pollution in Europe

The extent of water pollution in Europe is alarming. More than 500 chemicals have been identified in rivers across the continent, originating mainly from agricultural runoff and industrial processes. These chemicals, many of which are toxic or persistent, pose a significant threat to aquatic life, including fish, plants, and other organisms that rely on clean water to survive. The impact on biodiversity is profound, with certain chemical pollutants causing long-term harm to aquatic habitats and ecosystems.

The problem is compounded by the fact that many of these chemicals do not break down easily and persist in the environment for long periods. They can accumulate in the food chain, affecting both aquatic organisms and the humans who consume contaminated water or fish. As such, the need for effective water purification technologies has never been more urgent.

The Role of Diatoms in Water Purification

Diatoms are microscopic, single-celled organisms found in oceans, lakes, and rivers. They are known for their unique cell walls made of silica (silicon dioxide), a compound that gives them strength and structure. What makes diatoms particularly interesting for water purification is their highly porous structure, which allows them to absorb a wide variety of substances, including pollutants. This natural ability to trap contaminants is what caught the attention of researchers at the University of Duisburg-Essen.

Under the leadership of Junior Professor Dr. Anzhela Galstyan, the research team has explored the potential of diatomaceous earth—the fossilized remains of diatoms—as a material for purifying polluted water. By chemically modifying the diatom shells, they have enhanced the material’s ability to adsorb a range of chemicals, making it an effective tool for removing harmful pollutants from water.

The Research Breakthrough: Using Diatom Fossils for Pollution Removal

In their recent study, published in the journal Advanced Sustainable Systems, the team tested diatomaceous earth’s effectiveness in removing two common pollutants found in Europe’s rivers, particularly those affected by the textile industry: methylene blue and methyl orange. Both of these chemicals are synthetic dyes used in large quantities in the textile sector, and they often end up in water sources as a result of industrial runoff.

To improve the diatomaceous earth’s ability to capture pollutants, the researchers modified its surface by adding specific functional groups that increased its adsorption capacity. This modification made the diatom shells even more effective at attracting and holding onto pollutants, particularly the dyes used in the textile industry.

The results of their experiments were remarkable. The diatomaceous earth successfully removed a large percentage of the dyes from water in a relatively short period. Within one hour, up to 100% of methylene blue was removed from the water, whereas silica—a more commonly used material in water purification—was only able to remove 88% of the dye under the same conditions. For methyl orange, both silica and diatomaceous earth were effective, with both materials absorbing around 70% of the dye.

Advantages of Diatomaceous Earth in Water Purification

The findings of the study suggest that diatomaceous earth could become an essential material in the fight against water pollution. According to Dr. Galstyan, the key advantage of using diatomaceous earth is that it is an eco-friendly and cost-effective solution for water treatment. Unlike activated carbon, which is commonly used to filter water, diatomaceous earth is a renewable resource that can be cultivated with minimal energy input.

In addition to being environmentally sustainable, diatomaceous earth also offers practical benefits. Its effectiveness in removing pollutants was consistent across a variety of conditions, including changes in salt concentration and pH levels, which are common in natural water sources. This resilience means that diatomaceous earth could be used in a wide range of environments and conditions without the need for constant adjustments or complex processes.

Another significant advantage is that diatomaceous earth could potentially be used on an industrial scale. As Dr. Galstyan notes, the process of chemically modifying diatomaceous earth to improve its pollutant-absorbing properties is simple and could easily be scaled up for use in large-scale water treatment facilities. Given the growing demand for sustainable and effective water purification solutions, this method could help address both industrial and agricultural contamination in rivers and groundwater.

Looking to the Future: Membranes for Water Purification

The team at the University of Duisburg-Essen is not stopping at just improving diatomaceous earth for water purification. They are now exploring how the material could be used in membranes for more advanced water purification technologies. Membranes are widely used in processes like reverse osmosis and ultrafiltration, which are employed to remove contaminants from water on a large scale.

By incorporating diatomaceous earth into these membranes, the researchers hope to create a more efficient and sustainable way to purify water, especially in areas where water pollution is severe. The porous nature of diatomaceous earth could significantly enhance the filtration capabilities of these membranes, making them more effective at removing a wider range of contaminants.

The University of Duisburg-Essen has a distinct advantage in pursuing this research, as it houses the world’s largest collection of algae. This vast resource provides an ideal foundation for developing and testing new water purification technologies, including the use of diatomaceous earth in membrane systems.

Conclusion: A Promising Solution for Europe’s Water Pollution Problem

As Europe grapples with the rising challenge of water pollution, the work being done at the University of Duisburg-Essen offers hope for a more sustainable future. The use of diatomaceous earth, enhanced through simple chemical modifications, represents a breakthrough in water purification technology. Not only is it effective at removing harmful pollutants from water, but it is also environmentally friendly and cost-efficient.

This new method could play a key role in addressing the widespread contamination of Europe’s rivers and groundwater, helping to restore the health of aquatic ecosystems and ensuring clean water for communities. As the researchers continue to refine their approach, the future of water purification looks promising, with diatom fossils potentially playing a central role in solving one of the most pressing environmental challenges of our time.

Reference: Chidinma Akobueze Ojike et al, Surface‐Functionalized Diatoms as Green Nano‐Adsorbents for the Removal of Methylene Blue and Methyl Orange as Model Dyes from Aqueous Solution, Advanced Sustainable Systems (2025). DOI: 10.1002/adsu.202400776