资源环境科技发展态势分析平台

PM10 aerosol samples collected from a sub-urban site in Coimbatore during pre-monsoon, monsoon, post monsoon and winter from 2014 to 2016 showed a large variability from 7.6 to 89 mu g m(-3) with an annual average of 41 +/- 21 mu g m(-3) (N = 69). High abundance of PM10 and other components were recorded during winter and lowest during monsoon period. Total carbonaceous aerosols and water soluble ionic species contributed to 31% and 45% of PM10 mass respectively. SO(4)(2-)was the most abundant species (average similar to 9.8 +/- 4.8 mu g m(-3)) and constituted for 24% of total mass. Organic Carbon (OC) was the next most abundant species ranging from 1 to 16 mu g m(-3) with an average of 7 +/- 3.6 mu g m(-3) accounting for 17% of PM10 mass concentration. POC (primary organic carbon) and SOC (secondary organic carbon) accounted for 56%.and 44% of OC respectively. A major portion of OC (similar to 60%) was found to be water soluble. The correlation between OC and EC (elemental carbon) was found to be higher for night-time compared to daytime suggesting their origin from common sources during night-time. K+ was found to be strongly correlated with OC during nighttime. WSOC showed good correlation with POC and K+ which was high especially during night-time. WSON (water soluble organic nitrogen) accounted for 34% of water soluble total nitrogen (WSTN). HCO3- exhibited significant positive correlation with Ca2+ during daytime indicating their crustal origin. The observations suggest that the region is influenced by biomass burning sources, however during day-time, secondary production and terrestrial sources (due to high temperature and wind) significantly influence the atmospheric aerosols over this region.