Thallium and lead variations in a contaminated peatland : a combined isotopic study from a mining/smelting area

Vertical profiles of Tl, Pb and Zn concentrations and Tl and Pb isotopic ratios in a contaminated peatland/fen (Wolbrom, Poland) were studied to address questions regarding (i) potential long-term immobility of Tl in a peat profile, and (ii) a possible link in Tl isotopic signatures between a Tl source and a peat sample. Both prerequisites are required for using peatlands as archives of atmospheric Tl deposition and Tl isotopic ratios as a source proxy. We demonstrate that Tl is an immobile element in peat with a conservative pattern synonymous to that of Pb, and in contrast to Zn. However, the peat Tl record was more affected by geogenic source(s), as inferred from the calculated element enrichments. The finding further implies that Tl was largely absent from the pre-industrial emissions (>~250 years BP). The measured variations in Tl isotopic ratios in respective peat samples suggest a consistency with anthropogenic Tl (ε205Tl between ~ -3 and 4), as well as with background Tl isotopic values in the study area (ε205Tl between ~0 and 1), in line with detected 206Pb/207Pb ratios (1.16–1.19). Therefore, we propose that peatlands can be used for monitoring trends in Tl deposition and that Tl isotopic ratios can serve to distinguish source origin(s). However, given that the studied fen has a particularly complicated geochemistry (attributed to significant environmental changes in its history), it seems that ombrotrophic peatland(s) could be better suited for this type of Tl research

Unemployment in the district Jablonec nad Nisou

Práce se zabývá problematikou nezaměstnanosti v okrese Jablonec nad Nisou a analýzou podmínek pro její vývoj.Dokončená práce s úspěšnou obhajobo

Soil organic matter quality of variously managed agricultural soil in the Czech Republic evaluated using DRIFT spectroscopy

This study focuses on the effect of agricultural soil management on soil organic matter (SOM) composition. The addition of manure and crop residues was tested under different pedoclimatic conditions. The quality of SOM was assessed using diffuse reflectance infrared spectroscopy. The following parameters were calculated from the spectra:   sum of aliphatic bands (ΣAL), aromatic bands at wave numbers 1 620 and 1 520 cm-1 (AR1620 and AR1520), potential wettability (PWI), organic matter quality (OMQ), and decomposability (DI) indexes. The addition of manure or crop residues may not cause fundamental changes in the qualitative composition of SOM. Rather, pedoclimatic conditions determine which components are fixed in the soil on a long-term scale. A dominant effect of soil type was found in the distribution of all spectral parameters studied using main effect ANOVA. The main differences between the soil types concern the aromatic, oxygen and nitrogen groups contained in the SOM. Chernozems are soils with higher OMQ and DI, whereas Cambisols are soils with low OMQ and DI and the highest PWI. The stabilisation of SOM in soils can thus be based on the biochemical persistence of organic molecules, their specific affinity for minerals and the formation of aggregates that protect enclosed SOM