Evaluación de la concentración de contaminantes atmosféricos en el sector del By Pass de la ciudad de Riobamba.

Abstract

The purpose of the current research was to evaluate the atmospheric pollutants concentration in the BY PASS area, Riobamba city in order to verify the air quality in this heavy traffic flow area. For this study, it was necessary to determine the NOx concentration, considering 36 points placed 500 square meters around the influence area and using passive collectors which were previously prepared in the laboratory and placed 2.5 meters above the ground in posts or strategic places. The passive samplers apply the molecular diffusion process which catches NOx through a triethanolamine, n-butanol solution. The monitoring process was carried out during a 4-week period and the collectors were analyzed with the use of a UV spectrophotometer in order to determine their absorbance and establish the pollutant concentrations through formulae. Then, the traffic flow was established through the counting of the means of transport in 6 points of the area for their further simulation in Vissim PTV software; with the results obtained through maps, it was possible to observe the areas with the highest concentration of NOx. According to the measuring, it is established that the maximum value is 3042.527 µg/m3 in 8 days with a concentration of 380.32 µg/m3 a day, determining that this pollutant exceeds the allowed limits according to MAE, which establishes the value for NOx in 100 µg/m3 a year and 150 µg/m3 in 24 hours. This is due to the number of vehicles, shops and traffic lights. In addition, the study area is a clue point for the entry and exit of transport in Riobamba city. It is recommended to monitor the area for more than a month and ratify the data related to the concentrations of the pollutant studied.