AgWin - Waste water relevant silver loads in Vienna

AgWin - Waste water relevant silver loads in Vienna – Concretization of the causes or sources of silver loads in the sewerage and suggested measures to avoid
Ressourcen Management Agentur (RMA)
Unterstützt durch: 
Stadt Wien, MA 22

Project goal

The goal of this project is to provide a silver balance for the City of Vienna, whereby a special attention is paid to those silver loads which flow into the sewerage.




In the City of Vienna, the municipal sewage sludge is incinerated in the Fernwärme Wien GmbH - former Entsorgungsbetriebe Simmering (EbS), and the resulting bottom ash is landfilled. The current silver concentrations of the bottom ash range close to 50 mg/kg DM. The landfill ordinance defines a limit of 50 mg/kg DM of the material for landfilling. Therefore, after 2004 bottom ash with more than 50 mg/kg DM will not be approved for landfilling any longer.

The initial point for this study is the silver load in the sewage sludge (910 kg Ag/a), which has been determined in the main wastewater treatment plant. This silver load is compared with the most important application ranges of goods containing silver. By identifying the central processes of origin and goods, a substantial part of the silver load in the wastewater can be determined (720 kg Ag/a). Considering the interval width, the origin of the total silver load in the sewage sludge can be explained (300 – 1.600 kg Ag/a).