SEM-EDS and FTIR Characterization of Aerosols during Diwali and Post Diwali Festival over Delhi: Implications to Human Health

Emission from fireworks is a concern of pollution globally. This degrades the air quality for a small time interval and affects the human health and regional climate. Diwali, known as the festival of lights, is celebrated throughout India every year and the cracker bursting is a major activity in this celebration. To study the physico-chemical characteristics of particles released during this period, particles were collected at National Physical Laboratory (28°38'13'' N, 77°10'14'' E), New Delhi, India during Diwali festival celebrated on November 3, 2013 (Sampling period: October 29 - November 22, 2013). Particles were analyzed for organic functional groups, inorganic species and individual particle physico-chemical properties using FTIR (Fourier Transform Infrared Spectrometer) and SEM-EDS (Scanning Electron Microscope with Energy Dispersive Spectrometer), respectively. Bulk compositional analysis of few samples has been carried out using XRF (X-ray fluorescence spectrometer). Before Diwali, majorly mineral dust particles accompanied with some carbon rich particles with different morphologies were observed. Just after Diwali, zinc rich particle with multi-legged structures together with significant proportions of carbon rich particles sometimes mixed with Pb, K and S were observed based on SEM-EDS analysis. Submicron size (0.43 µm) particles were majorly observed to be Cu rich. XRF analysis reveals the dominance of TiO2, MnO, and CuO just after Diwali (November 4). FTIR analysis reveals the fundamental modes of nitrate, carbonate, silicate, zinc oxide, zinc hydroxide, iron oxide etc. The characteristic bands of CH2, N-O, C-H, C-O and NO2 were observed.