The characterisation of carbonaceous fly-ash particles from major European fossil-fuel types and applications to environmental samples

This paper describes the development of a technique to characterise carbonaceous fly-ash particles produced from five major European fuel-types (coal, oil, brown coal, peat and oil shale) using individual particle chemistries derived from energy dispersive spectroscopy as part of the EU COPERNICUS funded FLAME project. The final classification employed an hierarchy of quadratic discriminant functions such that 80% of the particles could be allocated to the correct fuel-type. The technique was then applied to particles extracted from the surface sediments of 196 lakes across four countries (UK, Estonia, Czech Republic and Ireland) so that the spatial distribution of impacts from these fuel sources could be determined. Spatial trends in fuel-type showed good agreement with known emission sources but absolute percentages were low in all countries due to high allocations to the “coal” fuel-type. It is thought that these high coal values are due to mineral particles surviving the acid pre-treatment. However, the results can still be used to determine sources of pollutant deposition. The technique is applicable to particles extracted from any depositional sink including, atmospheric collectors, building stone crusts, leaves and soils.