Estimativa experimental do fator de emissão veicular no Túnel Rebouças

Abstract

Currently, almost all major urban centers in the world suffer from air pollution. Therefore, great efforts are always being expended in the search for mechanisms that can identify, control and minimize the adverse effects of this problem. The understanding of all the dynamics of this process involves the comprehension of several factors and the search for solutions requires, increasingly, the consideration of several issues, that can be technical, behavioral and even meteorological. In light of this situation, and also considering that the main source of pollution, especially in urban environments, is the vehicular, a deeper analysis in this sense is necessary and, of course, goes through the characterization of the circulating fleet and the identification and quantification of the compounds emitted by the burning of the fuels. Therefore, the main goal of this study is to apply the Pierson and fuel-based methodologies for the determination of vehicle emission rates, a factor that quantifies the pollutants emitted by the vehicles to the atmosphere. In order to apply these methodologies, specific samples were collected, for the identification of carbonyl compounds, BTEX and PAHs, at two different points located inside the Rebouças tunnel. Taking into account that the typical fleet in circulation is mostly composed of light vehicles and also considering the distance between the sampling points and the concentration values, the vehicle emission rates were calculated. Averages of 6,85 ± 2,73 mg km-1 for formaldehyde, 3,76 ± 3,20 mg km-1 for benzene and 1,44 ± 1,01 mg km-1 for naphthalene were examples of calculated values, when Pierson methodology was applied, and 5,75 ± 2,19 mg km-1 , 2,51 ± 0,30 mg km-1 and 0,98 ± 0,44 mg km-1 , when fuel-based methodologies was applied. The emission rate values measured in this analysis took into account the "real world" of the circulating fleet, where vehicles are tested under the true handling, maintenance and fueled fuel conditions.