While Switzerland's wastewater treatment plants are of a high technical standard, the elimination of nutrients remains costly and energy-intensive. Eawag has now further developed a biological process, which simplifies the removal of nitrogen from sludge digester liquid, reducing costs by 50% for this treatment step.
EAWAG (2010): Reducing Wastewater Treatment Costs and Energy Consumption. Duebendorf: Swiss Federal Institute of Aquatic Science and Technology (EAWAG) URL [Accessed: 03.06.2019]