Scientists are exploring a new way to turn wastewater into valuable resources, paving the way for more sustainable materials.
Research from Aalborg University in Denmark, in collaboration with Delft University and Aarhus University, shows that wastewater treatment plants could be the key to creating eco-friendly biopolymers and harvesting essential minerals.
These biopolymers, produced by bacteria, offer a sustainable alternative to oil-based products. According to a recent study in Current Opinion in Biotechnology, this research is now ready for industrial production, setting the stage for practical use.
Professor Per Halkjær Nielsen from Aalborg University highlights the transformative potential of this approach: “We’re taking something that would otherwise be waste and turning it into high-value products.”
This project taps into the power of bacteria in wastewater, which produce biopolymers, or long chains of molecules, as they break down waste.
These biopolymers can replace synthetic materials currently derived from crude oil, making it possible to produce alternatives to plastics, adhesives, and other everyday materials.
Currently, oil-based synthetic polymers are widely used in many products, including plastic and textiles.
However, by using biopolymers produced at wastewater plants, we could soon have a more environmentally friendly option.
In wastewater treatment, bacteria consume incoming waste, leaving clean water behind. During this process, they create large amounts of biomass, with a significant portion being biopolymers, the sticky substance that bacteria use to form colonies and attach to surfaces.
Nielsen explains that many tons of biomass are generated daily, and much of it is usually converted into biogas for energy. Now, scientists are looking at other ways to use this biomass, especially the biopolymers, which industries need as sustainable replacements for oil-based materials.
These biopolymers can serve as binding agents in paper and building materials and help in flocculation, a process where particles clump together and settle in water, useful for purifying harbor sludge, lake water, and more. Additionally, these biopolymers appear to be naturally fire-retardant, making them even more valuable.
Wastewater treatment plants contain hundreds of bacteria species, each producing unique biopolymers with specific properties. By adjusting the pH and temperature, scientists can extract cellulose and gelatinous biopolymers from wastewater. These materials have applications in various industries, and researchers hope to scale up production so these biopolymers can be used globally. In Denmark alone, hundreds of thousands of tons of biomass are produced annually, hinting at a vast potential.
Another significant benefit of this process is the extraction of essential minerals, such as phosphorus, which the EU considers a critical raw material. With limited phosphorus sources, reclaiming it from wastewater could help meet future demand.
The REThiNk project aims to create the foundation for large-scale production, allowing wastewater recycling to expand beyond Denmark. This process requires mapping bacteria species globally, so scientists can understand how each one can contribute to biopolymer and mineral production.
“If companies see the product’s potential, they may invest in pilot plants to produce these materials at a larger scale,” Nielsen explains. Ultimately, this innovation could save endangered kelp forests by reducing the need for seaweed-based biopolymers, helping to preserve biodiversity and protect marine ecosystems.
