New material systems for clean drinking water

How can pollutants that are barely biodegradable and accumulate in the environment be removed from drinking water? This question is becoming increasingly important in light of stricter EU limit values. Particular focus is on so-called “forever chemicals” PFAS (per- and polyfluoroalkyl substances), which are considered a health concern and are increasingly posing technical and financial challenges to the water supply. Ahead of World Water Day 2026, attention is therefore also turning to innovative research approaches.

Water purification using electrical voltage

A corresponding approach is currently being developed at the Technical University of Hamburg within the Cluster of Excellence “BlueMat – Water-Driven Materials”. Prof. Mathias Ernst and his team at the Institute for Water Resources and Water Supply are researching novel material systems capable of specifically removing pollutants from water. Rather than merely retaining them, the aim is to selectively remove them from the water.

The basis for this is so-called “electrosorption”: in this process, electrically conductive materials are activated by an applied voltage and can specifically bind dissolved pollutants such as PFAS or heavy metals from the water. These are then concentrated in a solution where they can be efficiently treated further or destroyed.

Mathias Ernst and his team are still searching for suitable materials for this process and are currently testing carbon-based foams as well as nano- and microporous structures made of gold and silicon.

Efficient and resource-friendly

The aim of BlueMat is to develop sustainable alternatives to existing processes. PFAS are currently removed from water primarily using activated carbon. However, this must be replaced regularly and comes from resource-intensive sources such as wood or coconut shells. The process is therefore costly and only partially sustainable. Furthermore, it reaches its limits, particularly with short- and medium-chain PFAS.

This is where electrosorptive material systems could make an important contribution. “Another major advantage is that the operating costs are very low. We do not use high electrical currents, which makes the process very sustainable overall – especially when it is powered by green electricity,” says Prof. Mathias Ernst.

30 years of the DVGW Research Centre

In keeping with this, the DVGW Research Centre at Hamburg University of Technology, which is based at Prof. Mathias Ernst’s institute, is celebrating its 30th anniversary this year. For three decades, the centre has been combining scientific expertise with practice-oriented engineering work to ensure a sustainable and safe drinking water supply. In the laboratories, water quality is analysed and innovative water treatment processes are developed. Current research projects focus, among other things, on nitrate removal, the evaluation of antiscalants in reverse osmosis, and the stabilisation of microbiologically controlled processes for the removal of manganese and ammonia. Through the close integration of research and practice, the DVGW Research Centre continuously contributes to the further development of drinking water treatment and makes an important contribution to security of supply in northern Germany and beyond.