Atmospheric levels of formaldehyde and acetaldehyde and their relationship with the vehicular fleet composition in Salvador, Bahia, Brazil

Neste trabalho, dados de poluentes legislados e não legislados foram obtidos em uma região industrial-residencial no Rio de Janeiro, no período de abril a novembro de 2002. As concentrações de formaldeído e acetaldeído encontradas estavam na faixa de 25,25-231,73 ppb e 9,48-75,74 ppb respectivamente. Estas altas concentrações podem ser atribuídas a diversas fontes: emissões veiculares e industriais, a presença de incineradores de lixo, efluentes e rejeitos despejados no rio Faria Timbó e emissões de uma industria de metanol. As concentrações médias de BTEX foram: 1,92, 9,02, 6,37, 21,65 e 5,99 μg m -3 para benzeno, tolueno, etilbenzeno, m,p-xileno e o-xileno, respectivamente. As concentrações médias de PM 10 mostram valores máximos para o mês de outubro, abril e junho. As concentrações obtidas nas simulações foram para o mês de agosto usando um modelo de trajetórias. A concentração máxima de ozônio calculada foi de 39,8 ppb, as 15:00 horas, obtendo uma boa concordância com os dados experimentais (38,5 ppb). A isopleta de ozônio mostra que o local está em uma região alta de VOC/NO x , típica de áreas suburbanas e a favor do vento.In this work, data for criteria and non-criteria pollutants were obtained in a suburban industrial-residential area in Rio de Janeiro, from April to November 2002. Formaldehyde and acetaldehyde concentrations were found in the ranges 25.25-231.73 ppb and 9.48-75.74 ppb, respectively. These high concentrations may be attributed to several sources: vehicular and industrial emissions, the presence of several trash incinerators, effluents and waste rejected in the Faria Timbó river and emissions from a methanol industry. Average BTEX concentrations were: 1.92, 9.02, 6.37, 21.65 and 5.99 μg m -3 for benzene, toluene, ethylbenzene, m,p-xylene and o-xylene, respectively. PM 10 concentrations showed maximum mean values in October, April and June. Simulated concentrations were obtained for August 2002 using a trajectory model. The maximum calculated ozone concentration was 39.8 ppb, at 3:00 pm, in good agreement with experimental data (38.5 ppb). The ozone isopleths show that the local is in the high VOC/NO x region, typical of suburban and downwind areas.

Section: Air Quality Simulationmentioning

confidence: 81%

Experimental and theorical study of the air quality in a suburban industrial-residential area in Rio de Janeiro, Brazil

Rodrigues

Milas

Martins

et al. 2007

“…For diesel vehicles, formaldehyde emissions are expected to be significantly higher than acetaldehyde. The acetaldehyde/ formaldehyde ratio reported by de Andrade et al 22 for a given bus station was about 0.35. Additionally, light-duty vehicles in the parking area and circulating in the vicinity of the airport may contribute to aldehydes emissions.…”

Section: Resultsmentioning

confidence: 73%

“…Similar values were reported for a commercial mall parking lot and a business building parking lot, which may be considered a light duty vehicle signature. 22 The acetaldehyde emissions of these vehicles should contribute to increased acetaldehyde/formaldehyde ratios within the airport area.…”

Section: Resultsmentioning

confidence: 99%

Formaldehyde and acetaldehyde concentrations in the idle and taxiway areas of an urban airport

Guimarães¹,

Varandas²,

Arbilla³

2010

A fim de determinar o impacto das emissões de aldeídos num aeroporto, sobre a qualidade do ar, foram determinadas as concentrações de acetaldeído e formaldeído nas áreas de pouso e decolagem do aeroporto nacional Santos-Dumont no Rio de Janeiro, Brazil. O aeroporto está localizado a aproximadamente 1 km do centro da cidade e, no ano de 2007, teve uma média de 70.000 pousos e decolagens. Foram coletadas 129 amostras no período de março a novembro de 2007. Para o formaldeído foram observadas concentrações no intervalo 2,6 a 10,3 µg m -3 e para o acetaldeído, no intervalo, 4,3 a 19,7 µg m -3 . Durante a manhã, as relações A/F (acetaldeído/ formaldeído, em unidades de massa) se encontraram no intervalo 0,7-1,0. Nos horários da tarde as concentrações de formaldeído foram menores e as de acetaldeído aumentaram. As concentrações de formaldeído e acetaldeído estão no mesmo intervalo que valores previamente obtidos para o centro da cidade e possivelmente não afetem a produção de ozônio a nível local.To estimate the impact of aldehyde emissions at an airport on the air quality, formaldehyde and acetaldehyde concentrations were measured in the idle and taxiway areas of the Santos-Dumont national airport in Rio de Janeiro. The airport is located about 1 km from downtown Rio de Janeiro and had an average of 70,000 landings and take-offs during 2007. A total of 129 samples were collected in the period from March to November 2007. Formaldehyde concentrations ranged from 2.6 to 10.3 µg m -3 , and acetaldehyde concentrations ranged from 4.3 to 19.7 µg m -3 . During the morning, A/F ratios (acetaldehyde/formaldehyde ratios, in mass units) were in the range 0.7-1.0. In the afternoon, formaldehyde concentrations were lower and acetaldehyde concentrations generally increased. Formaldehyde and acetaldehyde concentrations were in the same range than values previously published for downtown and may not affect ozone production in a local scale.Keywords: aircraft engine emissions, aldehydes, airport air quality IntroductionThe impact of aircraft emissions on air quality has been investigated in several recent studies. Perl et al. 1 estimated the emissions due to aircraft operations at a mid-sized French airport in 1987, 1990 and 1994 and suggested a perspective of future emissions under different scenarios. These results show that, currently, aircraft emissions may be considered negligible in comparison with those generated by surface transportation sources. However, in the long-term, aviation might be considered a growing air pollution problem.Literature data show that the critical stages for aircraft emissions are those when the aircraft is waiting on the ground (the taxi and idle phases). In these phases, aircraft engines do not operate at their optimum conditions and emit significant amounts of carbon monoxide and hydrocarbons. 2 Pison and Menut 2 presented a analysis modeling of the aircraft traffic emissions impact on the ozone concentrations over Paris. They used a volatile organic compound (VOC) speciation reported by the Europe...

“…10,28,29 Briefly, the cartridges were conditioned with acetonitrile (4 mL) and then impregnated with 3 mL of an acidic solution of 2,4-DNPH (0.3 %). After this, cartridges were dried for 5 min under a gentle stream of Ultra Pure grade nitrogen, with a 2,4-DNPH coated cartridge connected in tandem to prevent contamination during the preparation.…”

Section: Cartridge Preparationmentioning

confidence: 99%

“…[7][8][9] The role of CC in the atmospheric chemistry is mainly due to the strong influence they have on the photochemical reactions, which lead to the formation of important air pollutants, such as ozone, nitric acid and peroxyacilnitrates. [10][11][12] Natural sources also contribute to the atmospheric concentrations of several CC, through biogenic emissions of some plants and photochemical oxidation of naturally emitted hydrocarbon precursors. 13 Many CC are classified as toxic air pollutants.…”

Section: Introductionmentioning

confidence: 99%

Emission profiles of carbonyl compounds at a Brazilian charcoal plant

Anunciação¹,

Sousa²,

Carvalho³

et al. 2012

A indústria siderúrgica brasileira consome grandes quantidades de carvão vegetal. As carvoarias são responsáveis por emissões atmosféricas de compostos orgânicos voláteis tais como compostos carbonílicos (CC). Neste trabalho, foram determinados o perfil e as concentrações de CC em fase vapor durante a produção de carvão vegetal a partir de eucalipto. As amostras foram coletadas próximas aos fornos, em cartuchos de sílica revestidos com 2,4-dinitrofenilidrazina e, em seguida, extraídas e analisadas por HPLC-DAD-MS (cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodo e espectrômetro de massas). Doze CC foram identificados e quantificados, entre eles acetaldeído e os pares coeluídos furfural/propanal, acroleína/propanona e 2-pentenal/pentanal. Estes três pares tiveram seus picos resolvidos por meio de espectrometria de massas para doze amostras e individualmente quantificados. Os perfis obtidos indicaram uma maior abundância do par furfural/propanal nas três fases de carbonização, seguido do acetaldeído na primeira fase e do 2-oxobutanal nas segunda e terceira fases. Furfural/propanal e acetaldeído se destacaram dentre os CC determinados nas proximidades dos fornos, com concentrações médias de 4948 e 2558 µg m -3 e concentrações máximas de 11655 e 4805 µg m -3 , respectivamente.Brazilian steel industry consumes huge amounts of charcoal. The charcoal plants are responsible for atmospheric emissions of volatile organic compounds such as carbonyl compounds (CC). In this work, the profile and the concentrations of CC in the vapor phase were determined during the charcoal production from eucalyptus. Samples were collected near kilns on silica cartridges coated with 2,4-dinitrophenylhydrazine, and then extracted and analyzed by HPLC-DAD-MS (high performance liquid chromatography coupled with diode array detector and mass spectrometry). Twelve CC were identified and quantified, amongst them acetaldehyde and the co-eluting acrolein/ propanone, furfural/propanal and 2-pentenal/pentanal pairs. These three pairs were peak resolved by mass spectra for twelve samples and thus individually quantified. The profiles obtained indicated the furfural/propanal pair as the most abundant in all three carbonization stages, followed by acetaldehyde in the first stage and 2-oxobutanal in the second and third stages. Furfural/propanal and acetaldehyde stood out among CC determined near the kilns, with average concentrations of 4948 and 2558 µg m -3 and maximum concentrations of 11655 and 4805 µg m -3 , respectively.Keywords: charcoal production, wood burning, carbonyl compounds, emission profiles, HPLC-DAD-MS IntroductionBrazilian steel industry is an important economic sector which consumes huge amounts of charcoal for producing pig iron. In order to meet their needs, many manufacturers have their own charcoal plants. The emissions from the wood burning process contain hundreds of chemical compounds, such as monosaccharide derivatives, aliphatic and aromatic hydrocarbons and oxygenated compounds, 1 which can be...