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1.
Prispevek zunanjih in notranjih virov ogljičnih delcev v različnih tipih stanovanjskih stavb : magistrsko delo
Klemen Levičnik, 2024, master's thesis

Abstract: Ogljični delci (del PM2,5) pomembno vplivajo na kakovost zraka. Sestavljeni so iz dveh frakcij, črnega ogljika (BC) in organskih delcev in so v večji meri posledica človeških aktivnosti, saj nastajajo pri nepopolnem zgorevanju ogljičnih goriv. Glede na optične lastnosti ločimo črni ogljik (BC), ki najbolj efektivno absorbira svetlobo preko celotnega spektra, in rjavi ogljik (BrC), ki absorbira v UV in modrem delu spektra. Kakovost zraka v notranjih prostorih zavisi od infiltracije delcev iz zunanjega zraka in notranjih virov. V kurilnih sezonah med leti 2021 in 2023 smo na jugovzhodnem delu Ljubljanske kotline merili koncentracije BC v zunanjem in notranjem zraku v treh različnih stanovanjskih stavbah (Novogradnja – NG, Kmečka hiša – KH, Povprečna hiša – SV) in na podlagi optičnih lastnosti določili delež BC iz prometa (%BCFF) in zgorevanja lesa (%BCWB). Preko sočasnih meritev CO2 smo ocenili tesnost stavbnega ovoja. Ugotovili smo, da kurjenje lesa v hladnejših mesecih pomembno vpliva na kakovost zunanjega zraka. Največjo tesnost stavbnega ovoja smo pričakovali pri NG, kjer sklepamo, da onesnažila v stavbo prihajajo preko rekuperacijskega sistema. Kljub temu smo v NG zabeležili najnižje povprečne urne koncentracije BC v notranjem zraku (1 µg/m3, 40 % BC glede na koncentracije v zunanjem zraku). Največjo tesnost stavbnega ovoja smo izmerili pri SV, kjer smo v prvem obdobju zabeležili 1 µg/m3 BC (60 % glede na zunanji zrak) in 1,7 µg/m3 (20 %) v drugem obdobju. Najvišje koncentracije BC smo izmerili v kmečki hiši (4 µg/m3 - 10 % in 2,8 µg/m3 - 60 %), kjer so višje koncentracije posledica slabe tesnosti stavbnega ovoja in prisotnosti intenzivnih notranjih virov delcev. Za vzdrževanje kakovosti zraka v stavbah odsvetujemo uporabo zastarelih kurilnih naprav, priporočeno pa je zračenje okoli poldneva, ko so zunanje koncentracije najnižje. Pri starejših stavbah je smiselna zamenjava dotrajanih oken in vrat, kar bi zmanjšalo potrebo po ogrevanju, pri novogradnjah z rekuperacijskim sistemom pa je smiselno poskrbeti za ustrezno filtriranje zunanjega zraka.
Keywords: ogljični aerosoli, črni ogljik, stanovanjske stavbe, viri onesnaženja, zrakotesnost, magistrske naloge
Published in RUNG: 09.02.2024; Views: 466; Downloads: 4
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2.
A device and a method for complete carbonaceous aerosol analysis in real time : European patent application EP4033242A1, 25. 8. 2021
Asta Gregorič, Matic Ivančič, Martin Rigler, 2022, patent application

Abstract: The present invention belongs to the field of methods and devices for analysing materials by determining their chemical or physical properties by the use of thermos-optical means. The invention relates to a device and a method for complete carbonaceous aerosol analysis in real time, which is essentially a system combining two different instruments, wherein the first instrument measures total carbon (TC) using flash heating of collected aerosol samples and generation of CO2, while the second instrument performs an optical attenuation analysis at 7 wavelengths from near UV (370 nm) to near IR range (950 nm) in order to characterize a Black Carbon (BC/EC) aerosols accumulated on a glass-fiber/PTFE filter tape. The device, i.e., the system of said instruments, collects and processes collected data of both instruments, wherein said processing may be performed by any of the instruments or by a separate processing means, computer or computer application.
Keywords: carbonaceous aerosol, black carbon, total carbon, brown carbon
Published in RUNG: 02.02.2024; Views: 230; Downloads: 5
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3.
Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameter
Luca Ferrero, Niccolò Losi, Martin Rigler, Asta Gregorič, C. Colombi, L. D'Angelo, E. Cuccia, A. M. Cefalì, I. Gini, A. Doldi, 2024, original scientific article

Abstract: Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter CAE) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R2 = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m−3) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter CMAAP). On a yearly time base the CAE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (CMAAP). Considering the seasonal behavior, higher experimental CMAAP and computed CAE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley. Overall, the agreement between the experimental CMAAP and CAE showed a root mean squared error (RMSE) of just 0.038 on the CMAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (−0.002 ± 0.455) and a high degree of correlation (R2 = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of CAE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N.
Keywords: aethalometer, C factor, loading parameter, MAAP, heating rate
Published in RUNG: 02.02.2024; Views: 252; Downloads: 3
.pdf Full text (3,18 MB)

4.
Optical properties and simple forcing efficiency of the organic aerosols and black carbon emitted by residential wood burning in rural Central Europe
Andrea Cuesta-Mosquera, Kristina Glojek, Griša Močnik, Luka Drinovec, Asta Gregorič, Martin Rigler, Matej Ogrin, Baseerat Romshoo, Kay Weinhold, Maik Merkel, 2023, original scientific article

Abstract: Abstract. Recent years have seen an increase in the use of wood for energy production of over 30 %, and this trend is expected to continue due to the current energy crisis and geopolitical instability. At present, residential wood burning (RWB) is one of the most important sources of organic aerosols (OA) and black carbon (BC). While BC is recognized for its large light absorption cross-section, the role of OA in light absorption is still under evaluation due to their heterogeneous composition and source-dependent optical properties. Studies that characterize wood-burning aerosol emissions in Europe typically focus on urban and background sites and only cover BC properties. However, RWB is more prevalent in rural areas, and the present scenario indicates that an improved understanding of the RWB aerosol optical properties and their subsequent connection to climate impacts is necessary for rural areas. We have characterized atmospheric aerosol particles from a central European rural site during wintertime in the village of Retje in Loški Potok, Slovenia, from 01.12.2017 to 07.03.2018. The village experienced extremely high aerosol concentrations produced by RWB and near-ground temperature inversion. The isolated location of the site and the substantial local emissions made it an ideal laboratory-like place for characterizing RWB aerosols with low influence from non-RWB sources under ambient conditions. The mean mass concentrations of OA and BC were 34.8 µg m-3 (max = 271.8 µg m-3) and 3.1 µg m-3 (max = 24.3 µg m-3), respectively. The mean total particle number concentration (10–600 nm) was 9.9 x 103 particles cm-3 (max = 53.5 x 103 particles cm-3). The mean total light absorption coefficient at 370 nm and 880 nm measured by an Aethalometer AE33 were 122.8 Mm-1 and 15.3 Mm-1 and had maximum values of 1103.9 Mm-1 and 179.1 Mm-1, respectively. The aerosol concentrations and absorption coefficients measured during the campaign in Loški Potok were significantly larger than those reported values for several urban areas in the region with larger populations and extent of aerosol sources. Here, considerable contributions from brown carbon (BrC) to the total light absorption were identified, reaching up to 60 % and 48 % in the near UV (370 nm) and blue (470 nm) wavelengths. These contributions are up to three times higher than values reported for other sites impacted by wood-burning emissions. The calculated mass absorption cross-section and the absorption Ångström exponent for RWB OA were MACOA, 370 nm= 2.4 m2 g-1, and AAEBrC, 370–590 nm= 3.9, respectively. Simple forcing efficiency (SFE) calculations were performed as a sensitivity analysis to evaluate the climate impact of the RWB aerosols produced at the study site by integrating the optical properties measured during the campaign. The SFE results show a considerable forcing capacity from the local RWB aerosols, with a high sensitivity to OA absorption properties and a more substantial impact over bright surfaces like snow, typical during the coldest season with higher OA emissions from RWB. Our study's results are highly significant regarding air pollution, optical properties, and climate impact. The findings suggest that there may be an underestimation of RWB emissions in rural Europe and that further investigation is necessary.
Keywords: wood-burning aerosols, optical characterization, black carbon, rural areas
Published in RUNG: 10.01.2024; Views: 321; Downloads: 4
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5.
Anthropic settlementsʹ impact on the light-absorbing aerosol concentrations and heating rate in the arctic
Niccolò Losi, Piotr Markuszewski, Martin Rigler, Asta Gregorič, Griša Močnik, Violetta Drozdowska, Przemek Makuch, Tymon Zielinski, Paulina Pakszys, Małgorzata Kitowska, 2023, original scientific article

Abstract: Light-absorbing aerosols (LAA) impact the atmosphere by heating it. Their effect in the Arctic was investigated during two summer Arctic oceanographic campaigns (2018 and 2019) around the Svalbard Archipelago in order to unravel the differences between the Arctic background and the local anthropic settlements. Therefore, the LAA heating rate (HR) was experimentally determined. Both the chemical composition and high-resolution measurements highlighted substantial differences between the Arctic Ocean background (average eBC concentration of 11.7 ± 0.1 ng/m3) and the human settlements, among which the most impacting appeared to be Tromsø and Isfjorden (mean eBC of 99.4 ± 3.1 ng/m3). Consequently, the HR in Isfjorden (8.2 × 10−3 ± 0.3 × 10−3 K/day) was one order of magnitude higher than in the pristine background conditions (0.8 × 10−3 ± 0.9 × 10−5 K/day). Therefore, we conclude that the direct climate impact of local LAA sources on the Arctic atmosphere is not negligible and may rise in the future due to ice retreat and enhanced marine traffic.
Keywords: light-absorbing aerosols, black carbon, climate change, heating rate
Published in RUNG: 21.12.2023; Views: 385; Downloads: 5
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