Archive News

September 11, 2018Wastewater smells foul and is full of pathogens. For these reasons it is usually removed and disposed of quickly. The out-of-sight-out-of-mind strategy is, however, costly and opportunities are lost. At Eawag’s Info Day, experts in practice come together with researchers who are seeking new answers – for example, on how nutrients or heat can be recovered from wastewater.

September 5, 2018Climate warming is not the only cause of temperature changes in lakes, rivers and other bodies of water. The use of waterbodies for heating and cooling also leads to increases or decreases in water temperature. There has been little research to date, however, on how this affects aquatic ecosystems. This lack of understanding has been highlighted by a recent literature review carried out at Eawag and the University of Bern.

August 15, 2018Eawag has studied how various pumped-storage hydropower scenarios affect temperature and water quality in the waterbodies concerned. In the case of Sihlsee, which serves as a reservoir for the SBB Etzelwerk plant, the question of withdrawal depth was found to be crucially important. The study also highlighted the fact that the assessment of environmental impacts largely depends on the definition of the reference state: whereas in natural lakes water is discharged from the surface, in reservoirs it is withdrawn from the lower layer. The environmental and aesthetic impacts of pumped-storage operations in the riparian zone were not examined in this study.

July 17, 2018Black plastic balls, which aim to reduce evaporation losses from open-air reservoirs under drought conditions, are not quite as efficient as previously assumed. Considerable quantities of water are already used in their production. 

July 5, 2018Small hydropower plants are often constructed on alpine streams, where they may have adverse impacts on sensitive ecosystems. Little is known, however, about the particular effects of individual plants, or the cumulative effects of multiple plants within the same river system. The current state of knowledge has now been reviewed in a study by Eawag researchers. 

June 15, 2018The CENTAUR sewer control system has been recognized as the ‘Most Innovative New Technology of the Year’ at the 2018 Water Industry Awards in England. CENTAUR stands for ‘Cost Effective Neural Technique for Alleviation of Urban Flood Risk’ and is funded by the European Union’s Horizon 2020 programme. Eawag researchers were part of this project.

April 30, 2018There is a wealth of energy and nutrients in wastewater. New processes enable the recovery of these resources from wastewater and sewage sludge, with the goal of redefining the function of the wastewater-treatment plants. Formerly energy users, they will become energy producers and the source of valuable fertilizer. This new technology has convinced the Swiss Climate Cent Foundation. It is contributing financial support to the construction of the new installation in the ARA Altenrhein.

February 22, 2018The earth’s water supply is changing because of global warming: the ratio of precipitation to evaporation is sinking, and additional arid zones may emerge. The speed at which this development is likely to take place has been analysed by an international team including Eawag researchers. 

February 19, 2018If the climate heats up, the temperature in the uppermost layer of lakes will increase, the thermic layering will become more stable and last longer, and less oxygen will reach the depths – this is the present theory on the effect of climate change on lakes.

February 15, 2018A shower hose will often contain more bacteria than the rest of the building’s plumbing system. A research team led by Frederik Hammes has been investigating this topic for the past four years. In their latest study, they analysed biofilms in 78 shower hoses from 11 countries, and in 21 of them, they detected legionella – a potential pathogen. In this interview, Hammes explains why we should not be unduly concerned.