Dicarboxylic acid in PM2.5 in Manaus: sources and quantification

Autor: Fernandes, Karenn Silveira, https://orcid.org/0000-0002-8753-8609
Přispěvatelé: Machado, Cristine de Mello Dias, Bataglion, Giovana Anceski, Wiedemann, Larissa Silveira Moreira, Barbosa, Cybelli Gon??alves Greg??rio, Martins, Leila Droprinchinski
Jazyk: portugalština
Rok vydání: 2021
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UFAM
Universidade Federal do Amazonas (UFAM)
instacron:UFAM
ISSN: 0183-2042
Popis: Submitted by Karenn Silveira Fernandes (karenn.silveira@hotmail.com) on 2021-11-25T20:33:47Z No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE - Karenn S. Fernandes.pdf: 4790512 bytes, checksum: 76777d8ea6d672b76fa9c01832042be9 (MD5) CartaEncaminhamento - TESE - Karenn S. Fernandes.pdf: 107541 bytes, checksum: b3ad0cff04945b8902c011836d80ee37 (MD5) Ata assinada.pdf: 824002 bytes, checksum: 36f2fd29cf8f60b041100fa2edf27bd2 (MD5) Approved for entry into archive by PPGQ Qu??mica (ppgqsecretaria@gmail.com) on 2021-11-26T17:17:26Z (GMT) No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE - Karenn S. Fernandes.pdf: 4790512 bytes, checksum: 76777d8ea6d672b76fa9c01832042be9 (MD5) CartaEncaminhamento - TESE - Karenn S. Fernandes.pdf: 107541 bytes, checksum: b3ad0cff04945b8902c011836d80ee37 (MD5) Ata assinada.pdf: 824002 bytes, checksum: 36f2fd29cf8f60b041100fa2edf27bd2 (MD5) Approved for entry into archive by Divis??o de Documenta????o/BC Biblioteca Central (ddbc@ufam.edu.br) on 2021-11-26T22:42:10Z (GMT) No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE - Karenn S. Fernandes.pdf: 4790512 bytes, checksum: 76777d8ea6d672b76fa9c01832042be9 (MD5) CartaEncaminhamento - TESE - Karenn S. Fernandes.pdf: 107541 bytes, checksum: b3ad0cff04945b8902c011836d80ee37 (MD5) Ata assinada.pdf: 824002 bytes, checksum: 36f2fd29cf8f60b041100fa2edf27bd2 (MD5) Made available in DSpace on 2021-11-26T22:42:10Z (GMT). No. of bitstreams: 4 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE - Karenn S. Fernandes.pdf: 4790512 bytes, checksum: 76777d8ea6d672b76fa9c01832042be9 (MD5) CartaEncaminhamento - TESE - Karenn S. Fernandes.pdf: 107541 bytes, checksum: b3ad0cff04945b8902c011836d80ee37 (MD5) Ata assinada.pdf: 824002 bytes, checksum: 36f2fd29cf8f60b041100fa2edf27bd2 (MD5) Previous issue date: 2021-10-27 Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico - CNPq The fine particulate material (PM2.5) is formed by several chemical compounds, whose largest mass fraction is composed of organic carbon. Among these, dicarboxylic acids (DCA) stand out because they can change the density of cloud condensation nuclei and the radiation and rainfall indices. However, little is known about them in PM2.5 in Manaus. In this sense, we analyzed the DCA (C2-C9) present in PM2.5 collected on quartz filters during the dry season of 2017 and 2018, in the day and night periods in Manaus, using gas chromatography coupled to a mass spectrometer (GC-MS). It was also analyzed the metals (ICP-OES), soluble ions (CI), black carbon (BC) (Reflectance), and levoglucosan (LEV) (GC-MS) present in the filter, to study sources and formation. The DCA was in greater concentration at night, with the night/2017 being the period with the greatest concentration. In descending order, the majority of compounds in the two years were C2>C3>C4. C2 was more concentrated at night. The occurrence of the linear regression between C2 and other acids (C3-C9) at night indicated the occurrence of nocturnal secondary formation in the aqueous phase, showing that the atmosphere is active even in the dark. Differences in the NH4+/SO42- ratio between the years indicated a probable difference in acidity in the particles. The PM2.5 night/2018 was the one with the highest ratio value pointing to slightly more basic particles. This variation may have caused lower concentrations of DCA at night/2018. The secondary formation of DCA was one of the main sources of DCA for the particle. Among the primary sources, there was the influence of burning fossil fuels and other associated sources (BC as a marker) in both years, with emphasis on PM2.5 collected in 2017. Another primary source was biomass burning (indicated by LEV), with emphasis on PM2.5 of 2018, due to the achievement of a positive linear regression between the concentration of C9 and the number of fire outbreaks in the metropolitan region of Manaus (R2: 0.720), as well as linear regression values between the total concentration of DCA and LEV (R2: 0.353) only for that year. Statistical and chemical evidence of the influence of the formation of Fe-oxalate and Cu-oxalate complexes were obtained in both years, however with greater strength for PM2.5 collected in 2018. The more significant presence of these complexes in 2018 may have influenced the sulfate concentration in the particles and, consequently, the difference in the acidity of the aerosol observed between the periods studied. Therefore, it was possible to know the organic composition in terms of DCA of particles collected in Manaus and observe the interaction of this organic aerosol with dissolved metals in the particle and with soluble ions, as well as the relationship of DCA and primary sources of particles in an urban environment related to burning (fossil fuel and biomass). The DCA collected in Manaus were influenced mainly by fossil burning, with changes in composition, formation, and degree of acidity when this organic aerosol was under a greater influence of biomass burning observed in 2018. O material particulado fino (MP2,5) ?? formado por diversos compostos qu??micos, cuja maior fra????o m??ssica s??o compostos de carbono org??nico. Dentre estes, os ??cidos dicarbox??licos (DCA) se destacam pois possuem a capacidade de alterar a densidade dos n??cleos de condensa????o de nuvens e os ??ndices de radia????o e pluviom??trico. Contudo, pouco se conhece sobre eles no MP2,5 em Manaus. Nesse sentido, analisou-se os DCA (C2-C9) presentes no MP2,5 coletado em filtros de quartzo durante a esta????o seca de 2017 e 2018, nos per??odos diurno e noturno em Manaus, utilizando cromatografia gasosa acoplada a um espectr??metro de massas (GC-MS). Analisou-se tamb??m os metais (ICP), ??ons sol??veis (IC), black carbon (BC)(Reflect??ncia) e levoglucosano (LEV)(GC-MS) presentes no filtro, para estudo de fontes e forma????o. Os DCA estiveram em maior concentra????o no per??odo noturno, sendo a noite/2017 o per??odo com maior concentra????o. Em ordem decrescente, os compostos majorit??rios nos dois anos foram C2>C3>C4. O C2 esteve em maior concentra????o no per??odo noturno. A ocorr??ncia de regress??o linear entre o C2 e demais ??cidos (C3-C9) a noite, indicou a ocorr??ncia de forma????o secund??ria noturna em fase aquosa, mostrando que a atmosfera est?? ativa mesmo no escuro. Diferen??a de valores da raz??o NH4+/SO42- entre os anos indicou uma prov??vel diferen??a de acidez nas part??culas. O MP2,5 noturno/2018 foi o que teve o maior valor da raz??o apontando para part??culas levemente mais b??sicas. Esta varia????o pode ter ocasionado menores concentra????es de DCA na noite/2018. A forma????o secund??ria dos DCA foi uma das principais fontes de DCA para a part??cula. Dentre as fontes prim??rias, observou-se a influ??ncia da queima de combust??veis f??sseis e demais fontes associadas (BC como marcador) em ambos os anos, com destaque para o MP2,5 coletado em 2017. Outra fonte prim??ria foi a queima de biomassa (indicada pelo LEV), com destaque para o MP2,5 de 2018, devido a obten????o de regress??o linear positiva entre a concentra????o de C9 e o n??mero de focos de queimada na regi??o metropolitana de Manaus (R2: 0,720), assim como valores de regress??o linear entre a concentra????o total de DCA e LEV (R2: 0,353) apenas para esse ano. Evid??ncias estat??sticas e qu??micas da influ??ncia da forma????o de complexos Fe-oxalato e Cu-oxalato foram obtidas em ambos os anos, entretanto com maior for??a para o MP2,5 coletado em 2018. A maior presen??a desses complexos em 2018, pode ter influenciado na concentra????o de sulfato na part??culas e consequentemente na diferen??a de acidez do aerossol observada entre os per??odos estudados. Portanto, foi poss??vel conhecer a composi????o org??nica em termos de DCA das part??culas coletadas em Manaus, observar a intera????o desse aerossol org??nico com os metais dissolvidos na part??cula e com ??ons sol??veis, assim como a rela????o dos DCA e as fontes prim??rias de part??culas em ambiente urbano relacionados ?? queima (combust??vel f??ssil e biomassa). Os DCA coletados na cidade de Manaus foram amplamente influenciados pela queima de combust??veis f??sseis, com altera????es na composi????o, forma????o e grau de acidez quando este aerossol org??nico esteve sob uma maior influ??ncia da queima de biomassa observada em 2018.
Databáze: OpenAIRE
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