Fortum Waste Solutions

Purpose and goal

Apply and investigate the potential of X-ray absorption spectroscopy (XAS) for determining the chemical forms of trace metals in waste incineration ashes, and obtaining indicators for handling ash sin a resource-efficient and sustainable way. Valuable knowledge on trace metals in waste incineration ash has been generated. The project has also contributed to the development of accurate and rapid routine analyzes at the BALDER beamline (MAX IV Lab) for ash samples. Fortum Waste Solutions, Sysav, NOAH, RISE, Chalmers University and Lund University/ MAX IV Laboratory were partners in this project.

Expected results and effects

New legislation for the classification of bottom ash from waste incineration has resulted in today´s assumption that the most dangerous form of zinc and copper is formed - unless proven otherwise. XAS is one of few methods identified as suitable for determining the chemical speciation/form of trace metals in the ash. In the project, XAS has been evaluated and new knowledge about the chemical forms of Cu, Zn and Pb in ash has been generated. The project contributed to a future routine method for ash analysis using XANES than can become commercially viable in the future.

Planned approach and implementation

In the project, XAS was implemented on a total of 16 ashes from waste incineration, for which the absorption edge of Zn, Cu and Pb was measured. In addition to these measurements, the structure of an open reference library was included. In total, XAS spectra were measured for 43 relevant chemical compounds purchased or synthesized for the purpose. XANES is considered to have high potential for determining the form of occurrence in the ashes for Zn and Cu, provided additional references are identified and included in the library.