Physical and chemical characterization and recycling potential of desktop computer waste, without screen

Environmentally appropriate and efficient recycling of several materials contained in waste electrical and electronic equipment (WEEE) requires knowledge and the identification of materials and chemical elements forming this kind of waste. Therefore, this study presents the physical and chemical characterization of desktop computer waste and the potential recycling rates of these materials. Differently from other studies, which investigated recycling and chemical composition only of motherboards (the component that contains precious metals), here were evaluate all components, namely floppy disk drives, CD drives, IDE cables, HDs, coolers, motherboards, power supply units, lids, casings, and other parts. This study was carried out in three steps: (i) the physical characterization included the manual dismantling of these components, and grouping the materials under seven categories (plastics, non-ferrous metals, ferrous metals, materials with substances of interest, hazardous materials, wires and cables, and other materials); (ii) potential recycling rates were calculated according to the European Directive 2102/19/EU; (iii) chemical characterization of components based on X-ray fluorescence spectroscopy. The results showed that the potential recycling rate of the waste analyzed was 96.66%, which represents the amount of material that can be recycled in the samples investigated. The results also show that, besides motherboards, other components also are potentially recyclable. Noble, precious, and critical metals as well as and rare earth elements were detected in IDE cables, power supply units, hard disks, floppy disk drives, and motherboards. Parts with high levels of aluminum, copper, and zinc were also observed. Recycling of WEEE is important both economically and environmentally, since PC components, since these elements may be recycled in processes that use less energy, preventing the extraction of natural raw materials and minimizing environmental impact.