| The East Junggar Basin of Xinjiang is both an arid desert area and a large open-pit coal mining area with serious dust pollution.Dust pollution will cause damage to surrounding plants,human health and ecological environment.To provide a certain theoretical basis for dust controlling,the pollution characteristics,influencing factors and dust source judgment of dust were regarded as an important content of research.The Beishan Coal Mine in the East Junggar Basin in Xinjiang area was used as the research area The PM2.5 and PM10 concentrations and wind speeds of different emission sources were monitored by portable read-only measuring instrument and anemometer.The daily average concentrations,maximum diffusion distance and variation law at different wind speeds of PM2.5 and PM10 were analyzed;using the Y09-3016 laser dust particle counter to measure the PM10 concentration of 1 m and 2 m high at the shelterbelt and the without shelterbelt site,and explore the protection forests at different heights and particle size concentrations.The concentration of Cu,Zn,Ni,Cd,Mn,Fe and Pb inorganic elements in the collected dust samples was determined by atomic absorption spectrometer,the pollution characteristics and spatial variation of inorganic elements in dust are analyzed.The source analysis of the pollution sources was carried out by the PMF model to determine the main pollution sources and their contribution rates in the study area.The following seven conclusions are mainly obtained.1.The daily average concentration of PM2.5 and PM10 of each emission source are: unpaved road > road > coal chemical plant > dump site.The PM10 of the unpaved road exceeds the 24-hour PM10 standard value of China's air quality grade.2.When the wind speed is 0.5 m/s,the concentration of PM2.5 and PM10 in the coal chemical plant is the largest among the various sources.When the wind speed is 1 m/s,the PM2.5 of the road and the PM10 concentration of the unpaved road are the largest,the PM2.5 and PM10 concentrations of the unpaved roads are the largest at wind speeds of 1.5 m/s to 2.5 m/s.The concentrations of PM2.5 and PM10 in coal chemical plants,dumping sites and soil roads were significantly positively correlated with wind speed(P<0.01).The concentrations of PM2.5 and PM10 on roads were not correlated with wind speed.3.The maximum diffusion distances of PM2.5 and PM10 for different emission sources are: coal chemical plant(800 m)> unpaved road(200 m)> dump site(150 m)> road(50 meters).4.The shelterbelt has obvious dust-retaining effects on PM10,and has significant dust-retaining effects on PM10 of 1m and 2m respectively(ANOVA,P<0.05).In the range of particle size of PM10,the shelterbelt had significant dust-retaining effects(ANOVA,P<0.05)for 0.3?m and 0.5?m,and without significant dust-retaining effects for 1?m,3?m,5?m and 10?m(ANOVA,P>0.05).The shelterbelt has a significant dust-retaining effects on the PM10 concentration in the 3H,and the best dust-retaining effects at 0.5H.5.The concentration of inorganic elements in each sample in the study area is: Fe(116.395 mg/kg)> Mn(2.960 mg/kg)> Zn(0.393 mg/kg)> Cu(0.317 mg/kg)> Ni(0.192 mg/kg)>Pb(0.184 mg/kg)>Cd(0.010 mg/kg),in which Pb,Cu and Zn elements are non-homogeneous distribution,which is strongly influenced by humans.6.The concentration of Zn,Fe,Ni and Mn is higher in areas with less pollution in coal dust and coal chemical plants;in areas with heavy pollution,the concentration of Cd,Cu and Pb is higher,and with horizontal distance increasing,the concentration of Pb and Zn in the downwind direction gradually increases.Among them,Pb pollution may be derived from coal chemical plant emissions.7.PMF source apportionment results show that the dust pollution sources in this study area are mainly from 6 dust sources,and their contribution rates are from large to small: coal dust(27.72%)> mixed dust(20.16%)> soil dust(19.80%)> road dust(13.32%)> factory emissions(9.93%)> automobile emissions(9.07%). |
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