During incineration of municipal solid waste (MSW) and sewage sludge, heavy metals are concentrated in the resulting ash. While strategies to recover precious metals and nutrients are being increasingly investigated, most of the ash still has to be disposed of in landfills. Leaching then results in the release of pollutants to the surface waters while sulfidation (in the case of Ag) strongly limits leaching of dissolved Ag. 

1. Sulfidation

2. Leaching



Case studies

Read also


Gogos, A., Wielinski, J., Voegelin, A., Emerich, H., and Kaegi, R. (2019) Transformation of cerium dioxide nanoparticles during sewage sludge incineration. Environ. Sci.: Nano, 2019, 6, 1765-1776.

Meier, C., Voegelin, A., Pradas del Real, A., Sarret, G., Mueller, C. R., & Kaegi, R. (2016). Transformation of silver nanoparticles in sewage sludge during incineration. Environmental science & technology, 50(7), 3503-3510



  Ralf Kägi

  EAWAG, Switzerland