Nastanak atmosferskih lebdećih čestica u urbanom okolišu

master's thesis

• Title (english): New particle formation (NPF) in an urban typology
• Author: Antonija Bikić
• Mentor: Marijana Kraljić Roković (mentor)
• Mentor: Kristijan Vidović (komentor)
• Committee member: Marijana Kraljić Roković (predsjednik povjerenstva)
• Committee member: Sanja Martinez (član povjerenstva)
• Committee member: Kristijan Vidović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Atmosferski aerosoli definiraju se kao relativno stabilne suspenzije krutih ili tekućih čestica u plinu. Unatoč niskoj koncentraciji, njihov broj i masena koncentracija, raspodjela veličina, fizikalna svojstva i kemijski sastav vrlo su značajni. Formiranje novih čestica može značajno povećati koncentraciju kondenzacijskih jezgri oblaka u atmosferi u samo jednom danu, a na nekim mjestima dolazi do više od dvostrukog povećanja. Stoga je stvaranje novih čestica (NPF) ključno za naše razumijevanje globalne klime i trebalo bi ga uključiti u klimatske modele. Uzorkovanje se provodilo u Ljubljani te ova lokacija predstavlja urbanu pozadinsku sredinu. Za uvid u brzine rasta čestica NPF-a provedeno je izravno uzorkovanje te izravno prikupljeni podaci su izanalizirani već postojećim algoritmima i matematičkim pristupima na instrumentima: Spektrometar za brojanje submikronskih čestica (SMPS, engl. Scanning mobility particle sizer) i etalometar (AEE33). Za neizravno uzorkovanje koristio se kaskadni impaktor (engl. Berner impactor) i PM2.5 uzorkivač (engl. PM sampler). Kemijska analiza uključivala je različite kromatografske metode (ionsku kromatografiju, tekućinsku kromatografiju visoke učinkovitosti s UV/VIS ili MS detekcijom i plinsku kromatografiju s
MS detekcijom), SEM-EDS analizu i elektroanalitičke pristupe. Posebna pozornost posvećena je površinski aktivnim tvarima (SAS) i njihovoj ulozi u urbanim NPF, te identifikaciji, fizikalnoj i kemijskoj karakterizaciji 6 karakterističnih dana s različitim događajima. Analiza je ukazala na ključnu ulogu SO2, NOx, VOC, O3 u procesu formiranja čestica. Iako je uloga SO2 značajna, analize čestica su istaknule da su ugljik, kisik i dušik prevladavali u najmanjim česticama
(s promjerom do 30 nm), ističući ključnu ulogu dušikovih spojeva i VOC-a za navedene dane.

Abstract (english)

Atmospheric aerosols are defined as relatively stable suspensions of solid or liquid particles in a gas. Despite their low concentration, both in terms of number and mass, as well as their size distribution, physical properties, and chemical composition, they play a significant role in atmospheric processes. The formation of new particles can significantly increase the concentration of CCN in the atmosphere in as little as a day, with some locations experiencing more than a twofold increase. Therefore, new particle formation (NPF) is crucial to our understanding of global climate and should be incorporated into climate models.
A systematic study was conducted at the urban site of Ljubljana using physical and chemical measurements (offline and online) to gain a better understanding of urban NPFFor insight into NPF physical growth rates a setup of online instrumentation was used; Scanning Mobility Particle Sizer (SMPS) and Aethalometer (AEE33). The offline setup consisting of a cascade impactor and PM sampler was used for the chemical characterization of the nucleation mode particles. The chemical analysis included different chromatographic methods (ionic chromatography, High-performance liquid chromatography with UV/VIS or MS detection, and gas chromatography with MS detection), SEM-EDS analysis and electroanalytical approaches. Special attention was given to surface-active substances (SAS) and their role in urban NPF and identification, physical and chemical characterization of 6 characteristic days with different events. The analysis indicated the key role of SO2, NOx, VOC, O3 in the process of particle formation. Although the role of SO2 is significant, particle analyzes pointed out that carbon, oxygen and nitrogen predominated in the smallest particles (up to 30 nm in diameter), highlighting the key role of nitrogen compounds and VOCs for the given days.

• Keywords: nove atmosferske čestice(NPF); atmosferski aerosoli; kondenzacijske jezgre oblaka(CCN); molekularni klasteri; urbana sredina
• Keywords (english): new particle formation (NPF); Atmospheric aerosols; cloud condensation nuclei (CCN); molecular clusters; urban sites
• Language: croatian
• URN:NBN: urn:nbn:hr:149:579017
• Project: Number: IP-2018-01-1717; Title: Rogozničko morsko jezero kao model odziva ekosustava na promjene u okolišu; Acronym: MARRES; Leader: Irena Ciglenečki-Jušić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra primijenjene kemije (sveučilišni/a magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-09-01
• Created on: 2023-11-21 11:18:32