Carbonaceous Aerosol Characterization and their Association with Meteorological Parameters at an Industrial Region in Delhi, India

The present study has been carried out focusing on the characterization of carbonaceous aerosol near an industrial region in New Delhi, India. It also determines the variation of carbonaceous species during the summer monsoon (SM) and winter monsoon (WM), interprets the morphological description of aerosol particles, identifies the major sources of carbonaceous aerosol, and recognizes the role of meteorological parameters in terms of OC-EC variability. PM₁₀ samples were collected and atmospheric organic carbon (OC) and elemental carbon (EC) were determined during SM and WM seasons in 2016–2017. Owing to high combustion and emission activities in the industrial area, the OC concentration was 70.3±53.7 and 94.3 ± 40.3 μgC/m³ during the SM and WM, respectively, with an overall average of 79.9±44.9 μgC/m³, and the EC concentration was 50.8 ± 53 and 62.6±49.8 μgC/m³, respectively, with an overall average of 58.3±46.7 μgC/m³. The morphological observations of collected particles were studied and the char/soot particles, iron-rich particles, and aggregates of calcium sulfate particles were observed during both seasons. The OC/EC ratio suggested the presence of mixed sources at the industrial location, predominated by industry and motor vehicle emissions. The relationship of carbonaceous aerosol with meteorological variables was also studied, and it was found that temperature, atmospheric stability, wind direction, and rain intensity significantly affect the levels of OC as compared to that of EC during both seasons. Furthermore, it was also noticed that high-intensity rain decreases the carbonaceous aerosol significantly and vice versa.