1161426 - Prediction of Deposited Ambient Dust in a Metallurgical City of Brazil Using Receptor and Dispersion Modelling

In the iron and steel making process, particulate matter is the main pollutant emitted to the
atmosphere. The emitted particles can disperse and depending on the size can deposit next to the
facilities. In Ipatinga, a metallurgical city located in Minas Gerais state, southeast of Brazil the
dust deposition was evaluated, using a dispersion and receptor modelling, in order to estimate the
contribution from the local emission sources. The Chemical Mass Balance (CMB) and Aermod
model were the modelling tools used to predict the deposited dust in four districts (BA, CA, BR
and VE) in Ipatinga. In all monitored districts, the CMB model results from the year 2020
showed that average contribution from the local industry was the main among emissions sources.
Due to the collinearity of the sources, the Aermod model was applied to evaluate the contribution
from different emission sources with chemical similarities. The Aermod simulated results were
in BA district were higher than other three districts. The CA, BR and VE districts had similar
simulated results. The validation of the Aermod model was done by comparing the simulated
with the observed values from the year 2020. The statistical tool used to evaluate the fitting was
factor of two (FAC2). Comparing the results, it was seen that the predicted values were
underestimated in BA and VE Districts and overestimated in BR and CA districts. The statistical
analysis showed that Aermod model yielded a satisfactory performance in simulating the dust
deposition in all districts. According to the modelling results, emissions from the dust deposited
on roads inside the local industry and from sinter plants contributed more than other emission
sources in all districts.