Qualitative X-ray fluorescence spectroscopy characterization of ground electronic waste

The potential of fungi to assimilate or mobilize metals and metalloids can be investigated using robust analytical methods, including X-ray fluorescence (XRF) spectroscopy. Knowing the chemical composition of WEEE is crucial for studying the mechanisms of interaction with fungi and, consequently, for selecting efficient fungal strains for biorecovery applications. In this study, multi-metal substrates obtained from ground electronic devices and provided by a private company, specialized in WEEE recycling, were subjected to granulometric separation through sieving. Each fraction was then characterized using XRF spectroscopy.XRF technique operates by exciting a sample with high-energy X-rays, which results in the emission of characteristic secondary X-rays from the material. The intensity and energy of fluorescent X-rays were measured to produce an XRF spectrum, displaying peaks corresponding to different elements and their concentrations within the sample.The results indicated an abundance of Cu, Sr, Zr, Sn, Ba, Br, Zn, Fe and Ni. In addition, the analysis of the finest-grained sample revealed trace amounts of Ga, Y, and In, elements of particular interest for this project. The XRF technique combined with the EDXRF detector has proven to be highly effective, enabling a rapid, non-destructive and simultaneous identification of the elements within the sample. This activity is part of the PRIN 2022-PNRR project, titled “Fungal interaction with metals (FUN METALS): transformation and mechanisms for biorecovery”, aimed at investigating the mechanisms and strategies through which fungi interact with Indium, Gallium, Germanium and Yttrium, elements of industrial and technological interest.