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Povzetek: The elemental composition of soils is governed by geogenic processes and anthropogenic activities. A comprehensive soil study was conducted on a national level, in which the elemental composition of soils from two different layers was compared with the intention to differentiate between natural and anthropogenic sources of elemental enrichments. Topsoil (0–5 cm) and subsoil (20–30 cm) samples were collected from 249 different locations on a national scale (Slovenia). Elemental composition for 55 major, minor, and trace elements (ICP-MS, aqua regia digestion) was determined on the fraction <0.063 mm. By calculating the enrichment ratios in different lithological units, it was determined that levels of Ti are higher in soils overlying metamorphic and igneous rocks, Zr and Ca are more abundant over carbonates, while levels of Ni are higher in soils overlying marlstones. Elevated levels of Hg were detected in subsoils in the historical Hg mining area in Idrija, which indicates the presence of nearby orebodies as a potential source for the geochemical anomaly. Spatial distribution of elements showed that higher levels of Pb, Zn, Cu, and Hg were detected in topsoils of urban areas, indicating that anthropogenic sources could be the potential cause of soil contamination. Pb, Zn, Cu, and Hg levels were up to four times higher in topsoils compared to subsoils sampled at historical mining areas (e.g., Mežica, Idrija, Litija), which shows that historical mining left a significant environmental impact. Although mining and smelting activities ended a few decades ago, soils in some areas are still heavily enriched with various metals. Some other potential anthropogenic sources of elements were identified, such as farming and ironworks. Based on the results of this study, we can conclude that by comparing elemental compositions of soils from different layers, we can recognise the origin of elemental enrichments.
Ključne besede: smelting, mining, urbanisation, traffic, ironworks, weathering
Objavljeno v DiRROS: 18.03.2024; Ogledov: 83; Prenosov: 33
Celotno besedilo (16,11 MB)

Povzetek: Cellulose acetate is used in many applications, including for cigarette filters. Unfortunately, unlike cellulose, its (bio)degradability is under question, yet it often ends up uncontrolled in the natural environment. The main purpose of this study is to compare the effects of weathering on two types of cigarette filter (classic filters and newer filters that have more recently arrived on the market) following their use and disposal in nature. Microplastics were prepared from polymer parts of used (classic and heated tobacco products—HTP) cigarettes and artificially aged. TG/DTA, FTIR, and SEM analyses were performed both before and after the aging process. Newer tobacco products contain an additional film made of a poly(lactic acid) polymer which, like cellulose acetate, burdens the environment and poses a risk to the ecosystem. Numerous studies have been conducted on the disposal and recycling of cigarette butts and cigarette butt extracts, revealing alarming data that have also influenced the decisions of the EU, who addressed the disposal of tobacco products in the EU Directive (EU) 2019/904. Despite this, there is still no systematic analysis in the literature evaluating the impact of weathering (i.e., accelerated aging) on the degradation of cellulose acetate in classic cigarettes compared with that in newer tobacco products that have recently appeared on the market. This is of particular interest given that the latter have been promoted as being healthier and environmentally friendly. The results show that in cellulose acetate cigarette filters the particle size decreased after accelerated aging. Also, the thermal analysis revealed differences in the behavior of the aged samples, while the FTIR spectra showed no shifts in the position of the peaks. Organic substances break down under UV light, which can be seen by measuring the color change. The PLA film was found to be more stable than cellulose acetate under the influence of UV light.
Ključne besede: cellulose acetate, cigarette filters, microplastics, artificial weathering, polymer degradation
Objavljeno v DiRROS: 30.06.2023; Ogledov: 340; Prenosov: 210
Celotno besedilo (5,78 MB)
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