title: Detection of greenhouse gas precursors from diesel engines using electrochemical and photoacoustic sensors.
abstract: Atmospheric pollution is one of the worst threats to modern society. The consequences derived from different forms of atmospheric pollution vary from the local to the global scale, with deep impacts on climate, environment and human health. Several gaseous pollutants, even when present in trace concentrations, play a fundamental role in important processes that occur in atmosphere. Phenomena such as global warming, photochemical smog formation, acid rain and the depletion of the stratospheric ozone layer are strongly related to the increased concentration of certain gaseous species in the atmosphere. The transport sector significantly produces atmospheric pollution, mainly when diesel oil is used as fuel. Therefore, new methodologies based on selective and sensitive gas detection schemes must be developed in order to detect and monitor pollutant gases from this source. In this work, CO(2) Laser Photoacoustic Spectroscopy was used to evaluate ethylene emissions and electrochemical analyzers were used to evaluate the emissions of CO, NO(x) and SO(2) from the exhaust of diesel powered vehicles (rural diesel with 5% of biodiesel, in this paper called only diesel) at different engine rotation speeds. Concentrations in the range 6 to 45 ppmV for ethylene, 109 to 1,231 ppmV for carbon monoxide, 75 to 868 ppmV for nitrogen oxides and 3 to 354 ppmV for sulfur dioxide were obtained. The results indicate that the detection techniques used were sufficiently selective and sensitive to detect the gaseous species mentioned above in the ppmV range.
authors.affiliation: Laboratório de Ciências Físicas LCFIS-Universidade Estadual do Norte Fluminense UENF, Av Alberto Lamego 2000, Campos dos Goytacazes, Rio de Janeiro, Brasil. georgiamothe@gmail.com
authors.forename: Geórgia
authors.initials: G
authors.lastname: Mothé
authors.forename: Maria
authors.initials: M
authors.lastname: Castro
authors.forename: Marcelo
authors.initials: M
authors.lastname: Sthel
authors.forename: Guilherme
authors.initials: G
authors.lastname: Lima
authors.forename: Laisa
authors.initials: L
authors.lastname: Brasil
authors.forename: Layse
authors.initials: L
authors.lastname: Campos
authors.forename: Aline
authors.initials: A
authors.lastname: Rocha
authors.forename: Helion
authors.initials: H
authors.lastname: Vargas
mesh_terms: D000397:Air Pollution / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis; D004563:Electrochemistry / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D005742:Gasoline; D009589:Nitrogen Oxides / Q000032:analysis; D061088:Photoacoustic Techniques / Q000379:methods*; D013458:Sulfur Dioxide / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D005742:Gasoline; D009589:Nitrogen Oxides; D001335:Vehicle Emissions; D013458:Sulfur Dioxide; D002248:Carbon Monoxide