SDG 6 : Clean Water and Sanitation

PFAS, often known as ‘forever chemicals’, are highly persistent pollutants that are difficult to remove from water, particularly at very low concentrations. One of the challenges for researchers is the sheer number of materials that could potentially be used to capture them. Researchers have tens of thousands of potential materials to explore, including metal-organic frameworks—porous materials that can capture pollutants—but testing each one in the laboratory is impractical.

In May 2025, Associate Professor Soumya Mukherjee of University of Limerick (UL) and Dr Mosab Bazargani of Bangor University received a Research Ireland-Wales Innovation Network Research Alliance Award to explore a different approach. The collaboration combines machine learning at Bangor with experimental materials chemistry at UL. Machine learning is being used to identify promising materials for the UL team to make and test for PFAS removal.

The collaboration builds on research published by Mukherjee and colleagues in Advanced Materials in 2025, which demonstrated rapid, recyclable PFAS capture using engineered, water-stable materials at concentrations as low as two parts per billion. The new collaboration is using those findings as a starting point for exploring a much larger range of potential materials.

Providing drinking water and managing consumption are everyday responsibilities on a university campus. University of Limerick’s (UL) Climate Action Roadmap 2025 documents an approach combining consumption monitoring, efficient fittings and access to drinking-water refill points.

Water Stewardship-certified personnel monitor campus water consumption using meters and dataloggers. These systems help identify unusual increases in usage, including those associated with leaks, so that problems can be investigated and repairs carried out.

UL has also adopted low-water-consumption fittings as standard in its buildings and maintains a network of water fountains and bottle-refill stations accessible to staff and students. These established measures form part of its ongoing approach to managing water resources.

Treating wastewater from dairy processing produces sludge rich in nitrogen and phosphorus. These nutrients have agricultural value, but the sludge’s high water content makes it difficult and costly to transport, leading to repeated land application close to processing plants. Nutrients lost through runoff and leaching can pollute waterways and encourage excessive growth of algae and aquatic plants.

In 2025, University of Limerick (UL) researchers Marzena Kwapinska, Anna Kaskova and James J. Leahy investigated alternative approaches to managing dairy processing sludge. Hydrothermal carbonisation, which treats material using heat and pressure in water, can reduce sludge volume while concentrating up to 95% of its phosphorus and approximately 50% of its nitrogen in a solid material called hydrochar. Pyrolysis, which heats material with little or no oxygen, provides another route to producing nutrient-rich biochar.

Dairy processing sludge also contains very low levels of heavy metals compared with municipal sewage sludge. By recovering valuable nutrients in more stable, transportable products, the research is exploring opportunities for their reuse in agricultural applications while addressing some of the environmental challenges associated with conventional sludge management.