| Shenyang is a typical heavy industrial city with serious air pollution.In this study,the atmospheric particulate matter in Shenyang City was taken as the main research object.The average concentration data of PM10 in Shenyang from 2011 to 2017 and PM2.5 in 2016-2017 were collected,and their characteristics with time were analyzed.The variation characteristics of atmospheric particulate matter PM2.5 and PM10 in Shenyang City generally showed a "U"-type change trend of two high and low intermediates,and the concentration was higher in January and December.The rest of the time was lower in the first half of the year and the upward trend in the second half of the year.The concentration of PM2.5 and PM10 in spring and winter is higher than that in summer and autumn.The dusty weather in spring frequently occurs,and the inversion weather in winter is frequent.In addition,the particles generated by burning coal are scattered into the atmosphere,which is caused by spring and winter.The main reason for the serious pollution in the two seasons;the daily average concentration of PM2.5 and PM10 in most of Shenyang City in 2011-2017 is between the national first-level standard and the second-level standard,and the period exceeding the national standard mostly appears in heating period.In this study,samples of TSP and PM10 were collected simultaneously from March 2017 to May 2018,and the samples were analyzed by water-soluble ion analysis,organic functional group analysis and micromorphology analysis.During the sampling period,the concentration of water-soluble ion Ca2+ in the PM10 sample ranged from 2.44 to 6.03 ?g/m3,the concentration of Mg2+ranged from 0.29 to 1.68 ?g/m3,and the concentration range of Na+ranged from 1.23 to 2.77 ?g/m3,and the concentration range of K+ It is 0.39?1.51 ?g/m3;the concentration of water-soluble ion Ca2+in TSP sample is 3.09?6.85 ?g/m3,the concentration range of Mg2+is 1.26?1.78?g/m3,and the concentration range of Na+ is 1.32?2.86 ?g/m3,The concentration range of K+is 0.41?1.59 ?g/m3;the highest concentrations of PM10 and TSP samples in spring,summer,autumn and winter are Ca2+.The TSP and PM10 samples were subjected to organic functional group analysis.Most of the samples had a hydroxyl stretching vibration absorption peak around 3400 cm-1,and the absorption peak around 1400 cm-1 was-CH-asymmetric bending vibration peak and located.The C-H out-of-plane deformation vibration peaks of different substitution degrees of aromatic structures at 900?700 cm-1.A few samples have asymmetric stretching vibrational peaks of methine groups in aliphatic hydrocarbons around 2900 cm-1,C=C stretching vibration peaks of aromatic rings and olefins around 1600 cm-1.Basically,the TSP sample is stronger than the PM10 sample.Scanning electron microscopy(SEM)was used to observe the micro structure of TSP and PM10,and the composition of the samples was measured by X-ray energy spectrometer(EDX).The characteristics of atmospheric particulate pollution in the spring,summer,autumn and winter seasons of Shenyang City were systematically studied.TSP and PM10 have different morphological characteristics in the four seasons,and the seasonal characteristics and spatial characteristics are obvious.In general,TSP and PM10 particles in four seasons in a year have uneven particle size distribution and irregular particle shape.In addition,there were fewer particles in summer and autumn,and the number of particles increased significantly in spring and winter.The research on the state of particulate matter pollution in the environmental atmosphere of Shenyang City provides a scientific basis for the relevant departments to control and improve the pollution of particulate matter in the environmental atmosphere of Shenyang City,and has certain guiding significance for the study of environmental air pollution in northern cities. |
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