In this seminar, Philipp Hänggi, visiting PhD student from University of Bern, Institute of Geological Sciences will give a presentation on his work about “Heavy metal speciation in municipal solid waste incineration bottom ash: implications and challenges for recycling".

Global municipal solid waste generation continues to increase and thermal treatment with energy recovery plays an important role in waste management.Switzerland and Sweden generally prohibit the landfilling of combustible waste, making incineration an established part of their waste management systems. Incineration generates fly ash, and in much larger quantities, bottom ash (BA). Despite extensive metal recovery, the processed mineral fraction of BA is still almost entirely landfilled in both countries, although recycling it could reduce the demand for primary aggregates and conserve landfill capacity. Currently, recycling is constrained by a small number of heavy metals, with elevated copper (Cu) and zinc (Zn) concentrations being among the major obstacles. However, since the release of Cu and Zn into the environment depends not only on their total concentrations but also on their chemical speciation and incorporation into the ash matrix, these properties must be characterized and taken into account.

The presentation gives an overview of Cu and Zn speciation in BA, based on complementary analytical techniques including synchrotron-based X-ray absorption spectroscopy (XAS). The results are discussed in relation to different post-combustion processing routes and their implications for the potential future recycling of the mineral fraction of BA.

Fika will be served from 11.00!

Most welcome!