Germanium and solid sample digestion with aqua regia: the nescience of chemistry basics and its sequels

Geochemical Characteristics and Preliminary Assessment of Geochemical Threshold Values of Technology-Critical Elements in Soils Developed on Different Geological Substrata Along the Sava River Headwaters (Slovenia, Croatia)

The increased demand for technology-critical elements (TCEs) in emerging technologies brings about the need to determine their spatial distribution in the environment and establish regulatory guidelines. In this paper, concentrations of Li, Sc, Nb, W, Ga, Ge, and REY (rare earth elements, including yttrium) in soils collected from different parent materials in the upper catchment of the Sava River (Slovenia, Croatia) were analysed. Results of multivariate (principal component analysis) and univariate (threshold methods) statistical techniques were used to determine geochemical characteristics of studied soils to identify the background variations and to establish geochemical threshold values. The investigated area is characterized by great lithological diversity and substantial variation of TCE concentrations. Among methods for assessment of geochemical threshold, the TIF (Tukey inner fence) and 97.5th percentile delivered the most reasonable results. Some exceedances above the 97.5th percentile were natural in origin, caused by local geology. These findings can provide baseline data because little is known about TCE variation on different geological substrata.

Studies on the Content of Selected Technology Critical Elements (Germanium, Tellurium and Thallium) in Electronic Waste

The article draws attention to the problem of the presence of metals: germanium (Ge), tellurium (Te), thallium (Tl), and others (Cd, Ba, Co, Mn, Cr, Cu, Ni, Pb, Sr, and Zn) in selected waste of electrical and electronic equipment (WEEE). As a result of the growing demand for new technologies, the global consumption of TECs has also been increasing. Thus, the amount of metals in circulation, of which the impacts on the environment have not yet been fully understood, is constantly increasing. Due to the low content of these metals in WEEE, they are usually ignored during e-waste analyses. The main aim of this study was to determine the distribution of Ge, Te, and Tl (and other elements) in ground sieve fractions (1.0, 0.5, 0.2, and 0.1 mm) of selected electronic components (solar lamps, solar cell, LED TV screens, LCD screens, photoresistors, photodiodes, phototransistors) and to determine the possible tendency of the concentrations of these metals in fractions. This problem is particularly important because WEEE recycling processes (crushing, grinding, and even collection and transport operations) can lead to dispersion and migration of TCE pollutants into the environment. The quantitative composition of e-waste was identified and confirmed by ICP-MS, ICP-OES and SEM-EDS, and XRD analyses. It was found that Ge, Te, and Tl are concentrated in the finest fractions of ground e-waste, together with Cd and Cr, which may favor the migration of these pollutants in the form of dust during storage and processing of e-waste.