Az energiaszektor légköri kibocsátásának éghajlati hatása szempontjából fontos primer és szekunder aeroszolok jellemzése = Characterization of primary and secondary aerosols relevant for climate effect of the atmospheric emissions of the energy sector

Az aeroszolrészecskék kémiai összetételének, morfológiájának és heterogenitásának jellemzése érdekében nagyérzékenységű roncsolásmentes mikroanalitikai módszereket fejlesztettünk és alkalmaztunk; a méret szerint frakcionált aeroszol nyomelemtartalmának meghatározásához totálreflexiós röntgenfluoreszcencia-analízist, az ammónium és nitrát mólarányának meghatározásához, valamint a szén és a cink kémiai állapotának vizsgálatához totálreflexiós geometriájú röntgenabszorpciós spektroszkópiát, egyedi részecskék morfológiájának és heterogenitásának jellemzéséhez elektronmikroszkópos méréseket. Kidolgoztuk a velük harmonizáló méret szerint frakcionált aeroszol-mintavételi technikát, lehetővé téve ugyanazon minta mérését mindhárom módszerrel. Megfelelően alacsony kimutatási határuk (< 1 ng/m3) miatt nagyon rövid mintavételi időkkel gyorsan változó légköri folyamatok nyomonkövetését teszik lehetővé. A módszerek teljesítőképességének bemutatását és a projekt keretében vett aeroszol-mintákon való alkalmazását kiegészítettük a másodlagos aeroszol keletkezését figyelembe vevő modellszámításokkal, a koncentrációk és az aeroszol optikai vastagság összevetésével, valamint kutatórepülőgépes mérésekkel. | In order to characterize chemical composition, morphology and heterogeneity of aerosol particles, highly sensitive non-destructive microanalytical methods were developed and applied. Total reflection X-ray fluorescence analysis was used for determination of trace elemental composition of size fractionated aerosol. X-ray absorption spectrometry was used for determination of the molar ratio of ammonium and nitrate, as well as for studying the chemical state of carbon and zinc. A sampling technique was elaborated that harmonizes with the microanalytical methods and allows the collection of size fractionated aerosols. This technique enables the measurement of the same samples with the three microanalytical methods. Because of the sufficiently low detection limits (< 1 ng/m3), the techniques are suitable for tracing of rapidly changing atmospheric processes using extremely short sampling durations. In addition to demonstration of the capabilities of the methods and their application to aerosol samples collected in the framework of the project, atmospheric dispersion model calculations were performed, taking into account the formation of secondary aerosols. The concentrations were compared with aerosol optical thickness data. The sampling apparatus was also tested during research aircraft missions

Stable isotope compositions and trace element concentrations in freshwater bivalve shells (Unio sp.) as indicators of environmental changes at Tiszapüspöki, eastern Hungary

Abstract Stable carbon and oxygen isotope compositions of living Unio shells and oxygen isotope compositions of water samples were determined in order to demonstrate how the shells' compositions can reflect environmental conditions. With this information in hand, fossil shell fragments from a sedimentary section at Tiszapüspöki covering the period of about 3.5 to 10 ky BP were analyzed for their stable isotope as well as trace element compositions. Beside the determination of sedimentary facies effects on the geochemical compositions, the combined evaluation of isotopic and trace element records allowed us to detect past environmental changes at a millennial scale. The data indicate that the period of 6 to 8 ky BP was characterized by humid summers that — on the basis of comparison with an Alpine speleothem record — was associated with a generally warmer climate and increased winter precipitation in the Alps

Experimental evaluation of the in-the-field capabilities of total-reflection X-ray fluorescence analysis to trace fine and ultrafine aerosol particles in populated areas

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Solid-state polymer membranes for simple, sensitive, and low-cost monitoring of mercury in water

Summarization: Solid-state Hg(II) selective membranes were produced and assessed by means of X-ray absorption near edge structure in the total reflection X-ray fluorescence (TXRF-XANES) setup and by the energy dispersive X-ray fluorescence (EDXRF) technique. Membranes were functionalized using four promising ligands for mercury complexation, i.e.: i) 4-(2-Pyridylazo) resorcinol (PAR), ii) thiourea, iii) calconcarboxylic acid (CCS), and iv) dithizone. A simple analytical procedure was followed, using miniscule reagent quantities, thus suggesting the process is also cost-effective. TXRF-XANES revealed that mercury complexes with the ligands, and is not simply adsorbed onto the PVC matrix, while the complexation was found to not be affected by the matrix existence. Mercury exhibited an increased oxidation grade and was covalently bound to the ligand functional groups, via a strong chemical bond. EDXRF revealed that the solid-state membranes can be used for mercury speciation and trace analysis from environmentally relevant matrices, such as tap water. The membranes could be a promising alternative to polymer inclusion membranes (PIMs), due to their simple configuration and high Hg (II) selectivity in aqueous media, but more research is needed. PAR appears to be the most promising ligand, followed by dithizone and thiourea. CCS had a minuscule preconcentration efficiency since it was preferably bound with Cu in tap water, indicating limited usefulness for mercury preconcentration. However, results suggest that, depending on the ligand, the solid-state membranes could be also possibly used for multi-elemental heavy metals analysis in water.Παρουσιάστηκε στο: Science of the Total Environmen

Microscale analysis of metal uptake by argillaceous rocks using positive matrix factorization of microscopic X-ray fluorescence elemental maps

Argillaceous rocks are considered in most European countries as suitable host rock formations for the deep geological disposal of high-level radioactive waste (HLW). The most important chemical characteristic in this respect is their generally strong radionuclide retention property due to the high sorption capacity. Consequently, the physico-chemical parameters of these processes have to be studied in great detail. Synchrotron radiation microscopic X-ray fluorescence (SR µ-XRF) has sufficient sensitivity to study these processes on the microscale without the necessity of the application of radioactive substances. The present study focuses on the interaction between the escaped ions and the host-rock surrounding the planned HLW repository. SR µ-XRF measurements were performed on thin sections subjected to sorption experiments using 5 µm spatial resolution. Inactive Cs(I), Ni(II), Nd(III) and natural U(VI) were selected for the experiments chemically representing key radionuclides. The thin sections were prepared on high-purity silicon wafers from geochemically characterized cores of Boda Claystone Formation, Hungary. Samples were subjected to 72-hour sorption experiments with one ion of interest added. The µ-XRF elemental maps taken usually on several thousand pixels indicate a correlation of Cs and Ni with Fe- and K-rich regions suggesting that these elements are predominantly taken up by clay-rich phases. U and Nd was found to be bound not only to the clayey matrix, but the cavity filling minerals also played important role in the uptake. Multivariate methods were found to be efficient tools for extracting information from the elemental distribution maps even when the clayey matrix and fracture infilling regions were examined in the same measured area. By using positive matrix factorization as a new approach the factors with higher sorption capacity could be identified and with additional mineralogical information the uptake capacity of the different mineral phases could be quantified. The results were compared with cluster analysis when the regions dominated by different mineral phases are segmented. The multivariate approach based on µ-XRF to identify the minerals was validated using microscopic X-ray diffraction

Edms model verification considering remarkable changes in airport traffic system

This paper presents the verification process of the Emission and Dispersion Modeling System adapted to evaluate the air quality of Liszt Ferenc International Airport. One receptor point was selected at the Airport, at Terminal Building 2 for the analysis, where an air quality monitoring station has been operating. Modeling results completed with background concentrations generated from another suburban monitoring station were compared with measured hourly concentrations using statistical indicators for three compounds (CO, NOX and PM10). Acceptable correlation coefficients (0.53-0.76) were obtained, however modeled PM10 concentrations were significantly underestimated. Pollution roses were generated that highlighted the areal distribution of the pollution sources influencing air quality at the receptor point. The contribution of aircraft movement and apron area emission was found to be well rated, but in case of CO and NOX small (17%) deficiency was found for ground vehicles emission, moreover a much higher (65%) difference was obtained for PM10 2018 Hungarian Meteorological Service.Scopu