Evaluación del comportamiento de los contaminantes atmosféricos O3, NO2 y COVs en el efecto fin de semana en el Centro Histórico de la ciudad de Riobamba.

Abstract

The behavior of the atmospheric pollutants O3, NO2 and VOCs in the weekend effect in the Historical Center of Riobamba was monitored twice a week, the nitrogen dioxide by passive samplers placed in 42 specific points within the domain, the collected samples were analyzed by UV-visible spectrophotometry. For the determination of ozone and volatile organic compounds, stoichiometric reactions and mathematical simulations were used; getting: nitrogen dioxide 26,510 µg/m³ during the week and 77,575 µg/m³ on weekend; volatile organic compounds 125,7x10 3 µg/m³ during the week and 53,88x10 3 µg/m³ on weekend, ozone 53,44 µg/m³ during the week and 170,00 µg/m³ on weekend, showing that none of these compounds are above the permissible limits established by the Law in accordance with Ministerial Agreement No. 050. It is concluded that ozone presents a higher concentration during the weekend due to the low vehicular mobility and the low generation of nitrogen dioxide and volatile organic compounds, promoting the longer stay of ozone in the atmosphere, due to the absence of the precursors and the inhibition of chemical reactions, this does not happen during the week, since the VOCs and NO2 emitted by the vehicles interact immediately with O3 avoiding that this can accumulate in the environment and cause affections to the citizenship. It is recommended to extend at one time the permanent monitoring to generate a database for a historical evolution analysis.