Evaluación del so2 y no2 empleando muestreo pasivo, en las parroquias la matriz y huachi grande, Cantón Ambato

Abstract

In this study, the sulfur dioxide and nitrogen dioxide concentration was evaluated in the La Matriz and Huachi Grande parishes in Ambato from October to December 2022. This period was chosen due to its large vehicular influx and productive activities. The passive sampling methodology was used with Triethanolamine and N-butanol capture solutions in plastic tubes placed at a height of 2.5 m with protection for which 20 arbitrarily selected monitoring points were initially defined; it was collected eight times for seven days. Subsequently, it was analyzed in the UV spectrophotometer, determining the absorbance values of each gas necessary to calculate their concentrations (ug/m3). The analyzes of the samples showed the highest concentrations for NO₂ with 119,967 ug/m3 in Huachi Grande as well as 119,314 and 115,589 ug/m3 for the Matrix, which are above the regulations, which establish a value no higher than 40 ug/m3, for SO₂. The highest concentrations were 130,208 and 127,048 ug/m3 in Huachi Grande; conversely, for the Matrix of 94,034 ug/m3, these exceed what is established by the regulations (60 ug/m3). This problem is mainly attributed to combustion's large influx of anthropogenic activities. The statistical analysis indicated that the NO₂ concentrations in Huachi Grande and La Matriz presented a normal distribution, while the SO₂ concentrations did not present a normal distribution. It is recommended that future work studies be carried out in the nearby areas, with a daily concentration analysis that allows for a more precise evaluation of the gas concentrations and to correlate the concentrations with the meteorological data that indicates the direct relationship with the distribution of pollutants.