Wastewater

Today, over 60 experts from research, federal and cantonal administration, the police, politics and hospitals are meeting to discuss the current status and future of wastewater monitoring in Switzerland. The current trends: a seasonal increase for influenza and the RSV virus, stagnating or even declining for coronavirus. We spoke to environmental engineer Christoph Ort, who, together with environmental microbiologist Tim Julian, established the field of wastewater-based epidemiology at Eawag and - in cooperation with external experts - is constantly adapting it.

With climate change, hot and dry summers are becoming more frequent, causing water shortages in some regions of Switzerland. Reusing treated wastewater could help to solve this problem. This has been demonstrated by an Eawag team on behalf of the FOEN and some cantons. The researchers also explain what still needs to be done to put the option into practice.

Researchers at ETH Zurich have developed a new way to break down a dangerous subgroup of PFAS known as PFOS. With the help of nanoparticles and ultrasound, piezocatalysis could offer an effective alternative to existing processes in the future.

Microorganisms in biofilms in rivers can break down harmful substances. Some are also able to degrade biocides, including the insect repellent diethyltoluamide (DEET) - or so it is thought. Researchers at the aquatic research institute Eawag have now discovered that DEET is degraded better when the proportion of treated wastewater in the water is high. They attribute this to specific enzymes that occur primarily where wastewater treatment plants return the water to the aquatic environment. However, the enzymes involved are not straightforward to predict.

Cities need to become more sustainable and use their water resources more efficiently. Managing water in small-scale cycles is one possible solution. A new white paper shows how this can be achieved.

Researchers at Eawag have analysed wastewater for antibiotic-resistant coliform bacteria. Monitoring wastewater can help to observe trends and regional differences, independent of the actual cases of illness.