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Abstract: Recent studies show that combining data with different time resolutions results in more detailed and likely more accurate source apportionment (SA) (Hopke et al., 2020; Manousakas et al., 2022; Via et al., 2023). Despite the advantages, SA studies, combining 24-hour filters and highly time-resolved analyses, are limited. This research aims to compare on- and off-line SA results in a pre-Alpine valley with a variety of sources. A comprehensive SA study of the local and regional PM sources and their size-segregated elemental fraction will be presented. PM10 was sampled daily on quartz filters from November 2020 to November 2021 and analyzed for a large array of chemical species. Equivalent black carbon (eBC) measurements were taken with the Aethalometer AE33. Hourly elemental PM10 and PM2.5 composition was measured in parallel with two Xact 625i from February until May 2021. Positive Matrix Factorization (PMF) was used to determine the sources of PM10 (off-line PMF) with 24-hour time resolution, and of the elemental fraction of PM (on-line PMF) with 1-hour time resolution for the overlapping time period. For off-line PMF, chemical species together with the source-specific eBC (Sandradewi et al., 2008) were used. For on-line PMF, two analyses were performed on the elemental composition: using PM10, and using a combination of PM2.5 and PMcoarse (PM10-PM2.5). The final off-line PM10 PMF results were compared to on-line elemental PM PMF and assessed accordingly. A combination of the different PMF models with various instrument data resulted in improved SA in terms of the number of identified sources and their uncertainties. The off-line PMF resolved ten PM10 sources (Fig. 1, left), while the on-line elemental PM10 and the combined elemental PM2.5+coarse PMF recognized 6 and 7 factors, respectively (Fig. 1, right). Due to large number of samples, we were able to separate between the sources with strong seasonality and sources featuring stability throughout the year. The study disclosed two rarely encountered factors, i.e., chloride-rich (chlorine-rich in case of on-line PMF) and cement dust. Introduction of source-specific eBC in the off-line PMF model resulted in more stable factor solutions.The high-resolution on-line PMF enabled us to distinguish between regional and local sources (see mineral dust factors). Furthermore, the size-segregated on-line PMF provided more speciated sources (traffic separation into heavy-duty and light-duty vehicles). A very good regression (R2 > 0.7, slopes = 0.05–0.35, p < 0.001) between the compared off-line PM10 and on-line elemental PM10 (daily averages) factors’ concentrations confirmed the adequacy of the SAs. Further work involves a direct comparison of fractions of the elements in the sources’ chemical profiles. The study clearly shows the advantages and limitations of the different PMF models. A combined use of various SA approaches appears to be a promising way towards a comprehensive analysis of the PM sources in complex environments.
Keywords: positive matrix factorization, PM10 composition, metals, Xact, HVS digitel
Published in RUNG: 24.01.2025; Views: 647; Downloads: 7
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Abstract: Viri, ki največ prispevajo k masi PM10, nimajo nujno najvišjega Oksidativnega Potenciala (OP), parametra, s katerim ocenimo možnost delcev PM, da oksidirajo testno spojino, s čimer ocenimo njihov nezaželeni vpliv na zdravje. V obsežni študiji analize virov PM10 in OP v Kanalu ob Soči smo izmerili koncentracije PM10, ki so primerljive z nekaterimi dolinami v Alpah in drugih hribovitih območjih Evrope, vrednosti OP pa so bile med najvišjimi izmerjenimi doslej v EU. Vira z največjim OP na enoto mase (OPm) kot tudi OP na enoto zraka (OPv) sta kurjenje biomase in vir bogat s kloridi, ki ga povezujemo z delovanjem cementarne. Izmerjene vrednosti OP v Kanalu ob Soči zahtevajo sprejetje ukrepov, ki bodo zmanjšali obremenitve antropogenih virov na ranljivo lokalno prebivalstvo.
Keywords: onesnažen zrak, delci PM, oksidativni potencial, določanje virov
Published in RUNG: 27.11.2024; Views: 760; Downloads: 1
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Abstract: Particularly during the cold weather season, countries of the Southeast Europe are experiencing some of the poorest air quality in the world due to the extensive use of solid fuels and old vehicle fleets. The city of Sarajevo is the capital of Bosnia and Herzegovina (BiH) situated within a basin surrounded by mountains. In the winter months (domestic heating season), topography and meteorology cause the pollutants to be trapped within the city basin. Countries of the Southeast Europe lack state-of-the-art atmospheric sciences research and access to sophisticated instrumentation and methodology, despite high levels of ambient pollution and position within the European Union (EU) borders, making it imperative to understand the emission sources, processing and the adverse health effects of atmospheric aerosol pollution.                This presentation will highlight the field measurements in Central and Southeast Europe during the Sarajevo Canton Winter Field Campaign 2017-2018 (SAFICA) and Sarajevo Aerosol Experiment 2022-2023 (SAAERO) projects, centered at the Sarajevo Bjelave supersite. Both projects were envisioned to produce crucial, not previously available information about aerosol emission sources and atmospheric transformations through a combination of online field and offline laboratory measurements. Online measurements during a) SAFICA and b) SAAERO included, a) black carbon, particle number and size distribution, and b) carbonaceous species, elemental composition and bulk chemical composition. SAAERO online measurements also included stationary and mobile measurements of gas- and particle-phase species on board the mobile laboratory in Sarajevo and Zenica, BiH, as well as in Ljubljana, Slovenia and Zagreb, Croatia. Finally, extended SAAERO project included measurements of black carbon at three additional urban centers: Ljubljana, Zagreb, and Belgrade, Serbia, enabling the first comparison of urban air quality in Central and Southeast Europe between two EU and two non-EU capitals. During both projects, laboratory aerosol analyses determined aerosol bulk chemical composition, selected elements (Huremović et al., 2020; Žero et al., 2022) and molecular species (Pehnec et al., 2020). Aerosol chemical composition determined by aerosol mass spectrometry was further analyzed by Positive Matrix Factorization to separate organic aerosol into subtypes characteristic of specific sources and atmospheric processes. Aerosol oxidative potential was also determined to evaluate aerosol ability to generate reactive oxygen species. Sarajevo and Belgrade have high ambient loadings of aerosol and black carbon, indicative of strong and diverse combustion sources and a major public health hazard. Finally, aerosol surface concentrations will be discussed in the context of European air quality. We thank Jasminka Džepina, Magee Scientific/Aerosol, TSI and Aerodyne for support. We acknowledge the contribution of the COST Action CA16109 COLOSSAL and SEE Change Net. KDž and ASHP acknowledge the grant by the Swiss NSF (Scientific Exchanges IZSEZ0_189495), KDž, GM and ASHP European Commission SAAERO grant (EU H2020 MSCA-IF 2020 #101028909), GM Slovenian ARIS grant (P1-0385), SF Croatian HRZZ grant (BiREADI IP-2018-01-3105), and AG, MR, MI, BA and IBJ Slovenian ARIS grant (L1-4386). Pehnec, G., et al., Sci. Tot. Environ., 734, 139414, 2020. Huremović, J., et al., Air Qual. Atmos. Health, 13, 965–976, 2020. Žero, S., Žužul, S., et al., Environ. Sci. Technol., 56, 7052−7062, 2022.
Keywords: air pollution, sources of pollution, PMF
Published in RUNG: 18.03.2024; Views: 3153; Downloads: 7
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Abstract: The contribution of traffic and wood burning to particulate matter (PM) across the Alps is widely recognized and studied (Herich et al., 2014 and references therein; Glojek et al., 2020). However, studies on valleys with cement production are scarce (Kim et al., 2003; Rovira et al., 2018) despite its large PM emissions and potential toxic properties (Erik et al., 2022; Weinbruch et al., 2023). We aim to identify and characterize sources’ contribution to the complex mixture of carbonaceous and mineral PM10 in a representative Alpine valley. Quartz filter samples of PM10 were collected daily from December 2020 to December 2021 and analyzed using different chemical techniques. In the same period equivalent black carbon (eBC) measurements were taken with the Aethalometer AE43. The measured species were analyzed using Positive Matrix Factorization (PMF) model (EPA PMF 5.0) with newly added tracers, i. e. source-specific eBC (Sandradewi et al., 2008) and organic species (2-MT, 3-MBTCA, phtalic acid, MSA and oxalate). The final PMF results were compared to online PMF-factors (SoFi Pro) derived from PM10 and PM2.5 elemental measurements (Cooper Xact 625i). Ten factors were identified at the site, including commonly detected biomass burning, traffic, nitrate- and sulfate-rich, aged sea salt and mineral dust. With the added additional organic traces, primary biogenic and secondary oxidation were recognized as well. In addition, two unusual factors were disclosed, contributing 10% to annual PM10. Namely, Cl-rich and a mineral dust-rich factor, which we name the cement kiln factor. We associate these two factors to different processes in the cement plant. The outputs of the study provide vital information about the influence of cement production on PM10 concentrations in complex environments and are useful for PM control strategies and actions.
Keywords: PM pollution, carbonaceous aerosols, source apportionment, industry
Published in RUNG: 10.01.2024; Views: 2296; Downloads: 0
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Keywords: Sarajevo, BiH, aerosol, ETAAS, ICP-MS, BenMAP, ExternE, SAFICA
Published in RUNG: 03.03.2022; Views: 2859; Downloads: 0
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