Speciation of Cu and Zn in bottom ash from solid waste incineration studied by XAS, XRD, and geochemical modelling

Millions of tons bottom ash (BA) is generated from incineration industrial and municipal solid waste each year within EU. The magnitude leaching metals like Cu Zn critical for hazard risk assessment these ashes. Although speciation a key factor to understand predict metal leaching, in BA not well known. In this study six separated carbonized were investigated by combination X-ray absorption spectroscopy, diffraction, leaching/extraction tests, geochemical modelling. Five the grate boilers one fluidized bed incinerator. aims identify similarities main species. several techniques was necessary draw conclusions about displayed coherent results. A similar indicated five studied boiler ashes although proportions between species may vary. Copper(II) oxide all BA. Zinc(II) willemite (Zn2SiO4) identified contained Zn-Si-minerals possibly franklinite or gahnite, while Zn(II) content low, if any. results have implications classification MIBA.