Hydrocarbon-based parameters for the identification of oil contamination in an area with brown coal mining: Emphasis on pyrogenic index and alkylated PAHs

The aim of the study was to propose hydrocarbon-based parameters that can ben used to identify oil derived contamination in an area with a long-term load of coal mining industry. Aliphatic hydrocarbons and PAHs have been quantified for bottom sediments in the Bílina River, Czechia. Presented data demonstrate that all river sediments are highly contaminated with PAHs. The results showed that the distribution of PAHs was not possible to interpret by using the standard evaluation due to multisource long-term sedimentation of petroleum by-products, coal tars, and accidents of processing industry in the river system. The presence of petroleum derived hydrocarbons has been initially screened by the bulk parameter TEH and confirmed by the occurrence of steranes, hopanes and the unresolved complex mixture (UCM) in the chromatograms. The identification of the biomarkers 25-Norhopane and Gammacerane point out onsite microbial degradation of parent hydrocarbon compounds. The interpretation of the ratios Fl/Py, An/P, BaAn/Ch were not decisive to prove petrogenic origin of PAHs in the river sediments. However, using the combined evaluation of TEH together with the ratio of low molecular over high molecular weight PAHs, pyrogenic index and the presence of specific oil derived biomarkers allowed to prove the presence of petroleum contamination. Environmental implication: Due to oil spill accidents and intensive coal mining over the years, polycyclic aromatic hydrocarbons (PAHs) have been present in extreme amounts in bottom sediments of a tributary of the Elbe River, so called the Bílina River. Due to its hydrophobic and carcinogenic character, mutual understanding of the fate of alkylated PAHs homologues are usually overlooked within EPA PAHs 16 monitoring programme. This study pays attention to alkylated PAHs homologues and conventional diagnostic ratios when identifying oil derived contamination

Late Carboniferous palaeodepositional changes recorded by inorganic proxies and REE data from the coal-bearing strata: An example on the Czech part of the Upper Silesian Coal basin (USCB)

In the Czech Republic, coal-bearing siliciclastic sediments have been deposited during the Serpukhovian and Bashkirian (Carboniferous). Until now, no attention has been paid to inorganic geochemical assessment of the coals and associated non-coal rocks from the mixed shallow-marine to continental sediments (Ostrava Formation), and continental non-marine settings (Karviná Formation). Samples were collected from a 750 m deep coal exploration borehole at the ČSM Mine. The bulk parameters, total organic carbon TOC, total inorganic carbon TIC, total sulphur TS, major elements, trace elements, and REEs were measured on these samples, and their mineral associations have been investigated using microscopy combined with the principal component analysis (PCA). Common redox proxies V/Cr, U/Th, Ni/Co, Mo/U, and the ratio S/TOC have been tested on the samples to investigate their usefulness for studying anoxia. Research concludes that redox proxies such as U/Th, Ni/Co and V/Cr have been strongly influenced by the clastic input and carbonates, which it hinders for them to be reliable indicators of anoxia. On the basis of Eu anomaly and REEs distribution, the primary source of detrital elements comes from the parent rock, being governed more by physical than redox processes.The Dominik Vöröš' Postdoctoral Fellowship at INCAR, Spain was financially supported by a grant (Project No. MSM100462001), provided by the Czech Academy of Science within the Research and Mobility Support of Starting Researchers Programme.Peer reviewe

Neutron Activation Analysis in Urban Geochemistry: Impact of Traffic Intensification after Opening the Blanka Tunnel Complex in Prague

Opening of the Blanka Tunnel Complex (BTC) in Prague, Czech Republic, the longest city tunnel in Europe, significantly increased traffic on a connected main road, the V Holešovičkách street (VHS). To study environmental changes in VHS connected with BTC opening, sampling of road dust and airborne particulate matter in the VHS vicinity started 3 years before BTC opening and continued until BTC pilot operation. The enrichment factors calculated for the collected samples from elemental compositions determined by instrumental neutron activation analysis (INAA) have shown significant enrichment for Se, Sb, Hg, Br, Mo, Zn, As, W, Cr, Ba, and Fe, but not their increase after starting BTC operation. The Principal Component Analysis allowed distinguishing between detrital and anthropogenic, probably traffic related, origin of the elements determined in samples. The study demonstrated a potential of INAA for multielement trace analysis of minute samples (28 elements determined in samples down to 20 μg, with detection limits down to sub-ng level) and its application in urban geochemistry studies

Neutron Activation Analysis in Urban Geochemistry: Impact of Traffic Intensification after Opening the Blanka Tunnel Complex in Prague

Opening of the Blanka Tunnel Complex (BTC) in Prague, Czech Republic, the longest city tunnel in Europe, significantly increased traffic on a connected main road, the V Holešovičkách street (VHS). To study environmental changes in VHS connected with BTC opening, sampling of road dust and airborne particulate matter in the VHS vicinity started 3 years before BTC opening and continued until BTC pilot operation. The enrichment factors calculated for the collected samples from elemental compositions determined by instrumental neutron activation analysis (INAA) have shown significant enrichment for Se, Sb, Hg, Br, Mo, Zn, As, W, Cr, Ba, and Fe, but not their increase after starting BTC operation. The Principal Component Analysis allowed distinguishing between detrital and anthropogenic, probably traffic related, origin of the elements determined in samples. The study demonstrated a potential of INAA for multielement trace analysis of minute samples (28 elements determined in samples down to 20 μg, with detection limits down to sub-ng level) and its application in urban geochemistry studies

The impact of saline mine water on fate of mineral elements and organic matter: The case study of the Upper Silesian Coal Basin

The work presented here provides a complex environmental impact of sediments in vicinity to the area of the former Lazy coal mine site in the Upper Silesian Coal Basin (Czech Republic). The main aim of this work has been to determine the degree of contamination, to describe the organic matter, and to carry out sorption isotherms to see the size and distribution of pores in the monitored sediments that are the crucial parameters to assumption of removal mechanisms of elements carried in mine water. The results show that the greatest enrichment of Mn, Sr, Ba, and was in sediments of the first tens of meters from the mine water discharge sediments. Ba and Sr were precipitated as mineral barite and thus formed a dominant insoluble component in the river sediments, which were further carried by water flow towards the water reservoirs. Predominant amounts of fossil material and smaller quantities of carbonized and recent organic matter were altered by weathering and erosion processes. The coal materials have a relatively beneficial sorption capacity, which increases with the carbon content. The overburden waste should be considered for use in removing heavy metals in-situ.This study was financially supported by the Czech Academy of Science within the Research and Mobility Support of Starting Researchers Programme (Project No. MSM 100462001, under the title Vanadium Migration in Coal Mining Areas: Sorption of V on Selected Clay Minerals). The authors also thank the ERASMUS + programme for supporting PhD student Lujza Medvecká with a research fellowship at RWTH Aachen University, Germany, and we thank Ivana Perná and Lenka Borecká for their aid in the laboratory work. The work also received support from Operational Program Prague—Competitiveness project “Centre for Texture Analysis” (No.:CZ.2.16/3.1.00/21538), and from the long-term conceptual development of research organisation RVO: 67985891.Peer reviewe

Microporous carbon foams : the effect of nitrogen-doping on CO2 capture and separation via pressure swing adsorption

This work investigates the effect of nitrogen doping on the porous structure and CO2 adsorption properties of hierarchically porous carbon foams, at different temperatures and pressures. A series of carbon foams with nitrogen contents of ∼7 to 13 at % is prepared by reaction of sodium ethoxide with different amino alcohols (namely monoethanolamine, diethanolamine, and triethanolamine), followed by thermal decomposition of the reaction product. The structure, morphology, porosity and chemical composition are studied using appropriate methods. The resulting material comprises micron-scale macropores combined with unrestricted micropores and mesopores embedded in the carbon walls. It is found that both nitrogen species and ultra-micropores contribute positively to CO2 uptake. The carbon foam with a nitrogen content of ∼7 at % (as well as an ultra-micropore volume of 0.44 cm3 g−1 and a specific surface area of 1549 m2 g-1) displays the highest CO2 uptake, adsorbing 5.14 mmol g−1 at 273 K, 3.22 mmol g−1 at 298 K, or 1.93 mmol g−1 at 323 K. This nitrogen-doped carbon foam adsorbs more CO2 than the undoped carbon foam reference, despite having significantly lower ultra-micropore volume and higher specific surface area. This highlights the importance of nitrogen species in CO2 capture. However, increasing the nitrogen content leads to suppression of the micropore volume, resulting in poor CO2 uptake. High CO2/N2 selectivity with good separation of CO2 from the CO2-N2 gas mixture, fast adsorption via physisorption, and excellent cycling durability are also observed, pointing towards the high regenerative ability of these materials