Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
J Environ Manage ; 346: 119024, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37738728

RESUMO

Radiocarbon (14C), stable carbon isotope (13C), and levoglucosan in PM2.5 were measured in two northern Chinese cities during haze events and nonhaze periods in January 2019, to ascertain the sources and their differences in carbonaceous aerosols between the two periods. The contribution of primary vehicle emissions (17.8 ± 3.7%) to total carbon in Beijing during that haze event was higher than that of primary coal combustion (7.3 ± 4.2%), and it increased significantly (7.1%) compared to the nonhaze period. The contribution of primary vehicle emissions (4.1 ± 2.8%) was close to that of primary coal combustion (4.3 ± 3.3%) during the haze event in Xi'an, and the contribution of primary vehicle emissions decreased by 5.8% compared to the nonhaze period. Primary biomass burning contributed 21.1 ± 10.5% during the haze event in Beijing and 40.9 ± 6.6% in Xi'an (with an increase of 3.3% compared with the nonhaze period). The contribution of secondary fossil fuel sources to total secondary organic carbon increased by 29.2% during the haze event in Beijing and by 18.4% in Xi'an compared to the nonhaze period. These results indicate that specific management measures for air pollution need to be strengthened in different Chinese cities in the future, that is, controlling vehicle emissions in Beijing and restricting the use of coal and biomass fuels in winter in Xi'an.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Emissões de Veículos/análise , Cidades , Material Particulado/análise , Monitoramento Ambiental/métodos , Carvão Mineral/análise , Estações do Ano , Carbono/análise , Aerossóis/análise , China
2.
Environ Pollut ; 299: 118908, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35091020

RESUMO

Wet deposition is a dominant removal pathway of carbonaceous particles from the atmosphere, but few studies have assessed the particulate carbon in precipitation in Chinese cities. To assess the characteristics and sources of particulate carbon, we measured the concentrations, fluxes, stable carbon isotopes, and radiocarbon of particulate carbon, and some cations concentrations in precipitation in Xi'an, China, in 2019. In contrast to rainfall samples, particulate carbon in snowfall samples in Xi'an showed extremely high concentrations and wet deposition fluxes. The concentrations as well as wet deposition fluxes showed no significant (p > 0.05) differences between urban and suburban sites, and they also exhibited low seasonality in rainfall samples. Water-insoluble organic carbon (WIOC) accounted for the majority (∼90%) of the concentrations and wet deposition fluxes of water-insoluble total carbon (WITC) in precipitation. The best estimates of source apportionment of WITC in precipitation showed that biological sources were the main contributor (80.0% ± 10.5%) in summer, and their contributions decreased to 47.3% ± 12.8% in winter. The contribution of vehicle exhaust emissions accounted for 11.7% ± 3.5% in summer and 39.0% ± 4.3% in winter, while the contributions of coal combustion were relatively small in summer (8.3% ± 7.0%) and winter (13.8% ± 8.5%). Biomass burning accounted for 25.7% ± 9.3% and 89.9% ± 0.7% of the biological sources in summer and winter, respectively, with the remainder comprising other sources of contemporary carbon. These results highlight the nonnegligible contributions of biogenic emissions and biomass burning to particulate carbon in precipitation in this city in summer and winter, respectively.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Carbono/análise , Isótopos de Carbono , China , Carvão Mineral/análise , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano , Emissões de Veículos/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA