Abstract
In this study, mass concentrations and physico-chemical characteristics of suspended particulates of aerodynamic size 10 μm (PM10) were evaluated. A dual E-Sampler which combines the light scatter and the gravimetric filter methods was used. Sampling occurred between August and December 2009. Scanning Electron Microscope – Energy Dispersive Spectrometry (SEM-EDS) and Inductively Coupled Plasma 6000 were used for elemental and physical characterization. The highest daily average mass concentration measured was 0.03543 mg/m3 and was below the international and national daily limit of 0.150 mg/m3, as well as the strict Vaal Triangle regional standard of 0.075 μg/m3. Relatively high daily average mass concentrations were obtained during the winter period. Concentrations of evaluated heavy metals decreased in the following order: iron (Fe) > manganese (Mn) > zinc (Zn) > copper (Cu) > vanadium (V) > titanium (Ti) > nickel (Ni) > lead (Pb). Positive correlations were established between Zn and Pb (r = 0.916); Zn and Mn (r = 0.883); Zn and V (0.984); Zn and Ni (r = 0.877); Zn and Fe (r = 0.914), which suggests common sources. However, Zn and Ti (r = 0.522); Zn and Cu (0.781) were poorly correlated.
Acknowledgments
The research was supported by Vaal University of Technology. The particulate E-Sampler was provided by the Department of Chemistry at the University of South Africa. All ICP and SEM-EDS analyses were done at the Arcelormittal South African Labs.