Research On The U,Th And PAHs Pollution Characteristics Of The PM₁₀ In A Uranium Mine

PM₁₀ and radioactive radon gas are the main pollutants in Uranium ore mining activities. The pollutants of PM₁₀ including radionuclides, heavy metals and organic pollutants and so on. These airborne particles contaminated the environment through the settlement and Air-proliferation.they (especially the diameter of less than 10μm of respirable particulate matter)are easily inhaled in the human body so as to have a serious impact on health.PM₁₀ samples were taken at Uranium mining area of east China in july of year 2007,and analyzed for Uranium,thorium,heavy metal and PAHs by ICP-MS,ICP-AES and High Performance Lipuid Chromatography(HPLC). The basic characteristics of PM10 pollution were studied, And investigate the thorium and uranium enrichment characteristics of the heavy metals in the moss plants. Followed is the main conclusion that thesis has got:(1) The differences of PM10 concentrations are very large in different spatial distribution. The concentration of particles is 60～80μg/m³ in sampling points 1, 2 and,and 130μg/m³,200μg/m³ in points 4 and 5.The main factors is single source of particulate matter, mainly from TSP of uranium mining and natural particulate matter in sampling points 1, 2 and 3. The source of particulate matter is more complicated in the points 4 and 5, not only uranium mining of the particles brought about long-range transport of pollution, the major is subject to the impact of human life.(2) The chemical elements of PM₁₀ is similar, the main element is composed of inorganic Al, Ca, Mg, which accounting for 75 percent of the sum elements mass, they are rich in the crust of the elements, mainly from the mine dust. In the high concentration of PM10, each element content accordingly higher, but the percentage of PM10 are not necessarily high quality.(3) Through enrichment factor analyzed, wo know that the enrichment factor of Cr, Cu, Pb, Ni,and Zn are more than 10,they are obvious enrich in the respirable particulate matter (PM10) and are the main the inorganic elements of PM10 Pollution, which may be caused by the coupling of participation of ground ore dust and dust (4) The highest concentration of uranium was 3 sampling points,but the concentr-ation of particulate matter (PM10) only 72.61μg/m3, the maximum concentration of thorium was 1 sampling point, and the concentration of particulate matter (PM10) only 70.02μg/m3. The highest PM10 was the sampling points 4 and 5, but content of thorium and uranium are relatively low. It is thought that uranium andthorium are from uranium mining, and the source of particulate matter is more complicated.(5) The heavy metal content of value the moss which in same environment was compared, the different habitats moss plants is not the same of the enrichment of heavy metals,tree>stone>soil.Bryophytes in nutrition mainly from the precipitation and atmospheric particles in the settlement, but the matrix can also affect the moss on the sensitivity of pollutants and enrichment capability, bryophytes matrix for the growth of certain elements of the absorption and assimilation.(6) Through the enrichment capacity of the moss can know that the Entodon compressus C. Mutll on the enrichment of uranium is relatively high, Haplocladium microphyllum, Hypnum plumaeforme the second level of enrichment, Plagiomnium Cuspidatum T. kop on uranium Enrichment is not too good. Haplocladium microphyllum on the thorium higher degree of enrichment, Entodon compressus C. Mutll, Sematophyllaceae Pylaisiadelpha yokohamae general enrichment, Plagiomnium Cuspidatum T. kop enrichment performing poorly. In different sampling points, with a moss on the uranium, thorium not the same degree of enrichment, with the main points of the pollutant concentration and the surrounding environment. The whole of Entodon compressus C. Mutll, Haplocladium microphyllum on the absorption of uranium thorium are strong.(7) The individual PAHs are below 100ng/m³, with the lowest concentration occurring at anthracene(0.21ng/m ) and the highest at benzo[b]fluoranthene(2.31ng/m³).The overall average concentrations of fluoranthene, chrysene,benzo[b]fluoranthene, benzo[k]fluoranthene, imdeno[1, 2, 3-cd]pyrene, benzo[ghi]perylene are higher, and those of phenanthrene, pyrene, benzo[a]anthracene, benzo[a]pyrene are in the middle, and those of acenaphthylene, acenaphthene, fluorine, anthracene, dibenzo[a, h]anthracene are comparatively lower. The pattern of higher abundance of four and more aromatic rings PAHs in the samples is an indicat or of incomplete combustion process of fossil and fuel at high temperature.