AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Day and Night Variability of Carbonaceous Aerosols over Urban Region of Northern India
ATAR SINGH PIPAL, Ajay Taneja, Dr. B. R. Aambedkar University, Agra, India
Abstract Number: 292 Working Group: Aerosol Chemistry
Abstract The organic carbon (OC) and elemental carbon (EC) associated with PM2.5 (fine particles) were investigated at a roadside, Agra, India during winter period. PM2.5 samples were collected for different time period i.e., 24-h, day and night by medium volume air sampler and analyzed for OC and EC using thermal optical transmittance protocol (Sunset- Lab). Average mass concentration of PM2.5 was 183±114 µgm-3, varied from 29 to 612 µg m-3. Carbonaceous analysis results showed that the average concentration of OC varied from 39 to 96 µg m-3 for 24-h, 71 to 89 µg m-3 for day and 64 to 91 µg m-3 for night while EC varied from 3.4-9.3 µg m-3, 8.9-16.8 µg m-3 and 12.4-18.2 µg m-3 for 24-h, day and night respectively. Estimated OC/EC was varied between 4.9 and 47 which suggest the presence of secondary organic aerosol (SOA) over the receptor area. Both OC and EC accounts for 43% of the total PM2.5 mass in which OC contributed major part (38 %) while EC contributed 5 % only. In order to know day and night variation relative abundance of OC and EC was higher during day time due to vehicular emissions. Beside this high biomass burning, fossil fuel combustion could not be ignored as study was conducted during winter period. During winter people burn bio-fuels for cooking and also used to protect from the cold. Significant correlation among OC (0.83) and EC (0.97) to PM2.5 was observed for 24-h samples, indicates the similar sources. Being high loading of OC and EC associated with fine particles inferred very unsafe air quality for human health as well as regional climate change. It is also suggested to take necessary and immediate action in mitigation of the emission of carbonaceous aerosol in the northern part of India.