To determine the mineral and geochemical composition of the soil and its possible contamination with potentially toxic elements (PTE), 10 soil samples were taken in Tivoli Park. Samples were taken at locations where contamination is expected to be higher (proximity to roads and railways) and at locations where contamination is not expected to be present.
The geochemical composition of the samples was analysed by XRF. The four soil samples that differed most in chemical composition were analysed by XRD to determine the mineral composition. The two samples with the most elevated levels of potentially toxic elements were examined under SEM/EDS to identify possible carriers.
We found that some parts of the park are more enriched in Cr, Cu, Mo, Ni and Pb. The most elevated levels are found in samples TI-06 and TI-07, which are located along Celovška cesta and the parking lot next to it. The Cu content of sample TI-07 is interesting as it is very high (138 mg/kg) and stands out compared to the other samples. However, the elevated levels are not related to the location along major thoroughfares or where contamination was predicted. The results were confirmed by the Mann-Whitney test, the EF and Igeo pollution coefficients and the PSP distribution maps. XRD analysis showed that the soil in Tivoli is dominated by quartz, followed by muscovite, chlorite, dolomite, calcite and albite. Sample TI-04, located in the children's playground, stands out in terms of its mineral composition, as it has an increased amount of dolomite, which, given the lithological background, is the result of embankment filling. SEM/EDS analysis confirmed the presence of the same minerals as indicated by XRD, while very few PSP-bearing particles (Cr, Ni, Cu) were detected. Comparison with soils in the Rožnik area and on the river terraces of the Sava in the vicinity of Smlednik showed that the soils of Tivoli are enriched in CaO, MgO and PSP, which is due to anthropogenic influence. PSP levels in Tivoli Park soils are higher than those in nine world cities, indicating that there is no direct correlation between population density and pollution.
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