Background & Objectives: In addition to determining the chemical characteristics of particles in the air of cities, investigating the physical properties and their role in environmental pollution is also important. So the aim of this study is the investigation of morphological and mineralogical of PM2.5 particles in the air of Tehran, relying on the analysis of EDX-SEM images and XRD analysis.
Methods: In this study, samples of PM2.5 particles in the air of Tehran Sina Hospital area were collected by frmOMNITMAmbient Air Sampler with PTFE filter with a diameter of 47 mm. Evaluation the mineralogical composition, size, and size percentage frequency and Finally, to determine the shape of particles XRD analysis and EDX-SEM images were used.
Results: The results of EDX-SEM images analysis showed that the most important elements in PM2.5 particles are oxygen (07.43-32.39%), calcium (49.7- 48.5%), aluminum (72. 5-32. 5%), iron (42.3- 21.3%), magnesium (79.1-19.1%), potassium (57.1-5.1%), zinc (48.1- 28.1%), and some particulates, sulfur (61.4%), sodium (66.0-51.0%), fluorine (61.0%) and titanium (53.0%) have also been found. XRD results showed that the mineral constituent of the samples studied,are mostly in the fourth phase of the mineral core containing carbonate (mostly calcite), clay (Askm Tate and Kahn Ditte), silicates (mainly quartz) and Philo silicates (mainly kaolinite). Minor phases include minerals such as muscovite, illite, calcite and Palygurskyt.
Conclusion: These elements are defined and identified as components originating from the Earth's crust and human activities have no large role in the production and release of these elements. In most particulate matter, carbon element has also been detected in some particles, although the carbon could not be identified. The high percentage of carbon in some aerosolsof this element is to indicate the origin of fossil fuels. Comparing the results of XRD and SEM-EDX analysis, itshowed that these results are well proved. |
