Characterization of suspended particulate matter using cascade impactor and X-ray fluorescence

Abstract

Atmospheric pollution has become one of the biggest environmental and public health problems in large urban centers. The process of industrialization and urbanization of large cities together with population growth and motorized transport has caused an increase in the level of air pollution in these places. Thus, this work approaches the characterization of suspended particulates in the surroundings of the Duque de Caxias Refinery (REDUC) from the identification of the chemical elements present using the X-ray fluorescence technique - XRF. A PIXE 8-stage impactor was used to collect the particulate material (aerodynamic diameters of 16 – 0.12 µm). On the other hand, the experimental measurements of XRF were performed using a commercial system ARTAX 200 (Bruker) and under the following conditions: voltage of 45 kV, current of 500 µA, acquisition time of 300 s and no filter in the incident X-ray beam. The study allowed estimating the dimensions of the particulate materials, identifying the chemical elements present and pointing out possible sources, from samples collected in three residential points that are in the surroundings of REDUC in the region of Campos Elísios. The X-ray fluorescence technique proved to be efficient and it was possible to detect the following chemical elements: Silicon, Sulfur, Chlorine, Potassium, Calcium, Titanium, Manganese, Iron, Nickel and Zinc. Correlations were observed between some elements making it possible to identify possible sources of pollution.