Physicochemical Properties Of Ambient Aerosols During Winter And Spring In Northern Suburban Of Nanjing

To understand the physicochemical properties of aerosol in 2014 and 2015 in northern suburb of Nanjing.The data of this article were analyzed by Anderson Nine Impact Sampler,KC-120H Sampler,Nephelometer,ion chromatograph and heat/light carbon analyzer.In this research,size distribution characteristics,source of particles and the relationship of chemical components and scattering coefficients were analyzed.While this research was connected with the ground meteorological elements and backward trajectory for observation.The results showed that NH₄⁺,NO₃^-and SO₄^2-were in the form of?NH₄?₂SO₄ and NH₄NO₃ under hazy and non-hazy days.The industrial emission,biomass burning and secondary reaction were the most important pollution sources of ions.Ratios of OC and EC indicated that the main sources of carbonaceous particles were vehicle exhaust,coal combustion and biomass burning during hazy days.In January 2015,the average mass concentration of PM_2.5,SO₄^2-,NO₃^-and NH₄⁺in the heavy pollution days was 4.0,6.4,3.1 and 3.9 times of clean days,respectively.Two kinds of acid pollution days were mainly affected by the flow source.The proportion of fixed source in the heavy pollution days was larger than light/moderate pollution days.Coal combustion,motor vehicle exhaust emissions and road dust were the main contributors to carbonaceous substances by abundances of carbonaceous components.The daily scattering coefficient was?423.36?265.34?Mm^-1.The diurnal variation of scattering coefficient during the total measurement period showed a three-peak shape with peaks at 05:00,14:00 and 18:00²0:00.The reconstructed scattering coefficient correlated closely with the measured value.This result indicated that the IMPROVE equation could be used to reflect the relationship between the scattering coefficient and the chemical compositions.NH₄NO₃,?NH₄?₂SO₄ and OC was the main contributors to the scattering coefficient.