Study On Soil Arsenic Pollutants Characteristics And Repairment Effects Of Daliuta Coal Mine

In the process of coal mining,processing,transportation and utilization,arsenic pollutants go into the soil,the atmosphere and the water environment;and they migrate and transform,threatening the ecological environment of the mining area.This thesis sets Dalivta mining area in Inner Mongolia as study area to study its coal ecosystem and soil ecosystem,the mineral composition in coal was analysed by scanning electron microscopy and XRD.Arsenic content and modes of occurrence in coal and soil were obtained by microwave digestion and andatomic fluorescence spectrometry.The arsenic pollutants characteristics of the study area soil were studied by source apportionment.The abundance and the amount of soil microbial communities were sequenced based on PCR-DGGE.The effects of the arsenic content in soil have on plant diversity and the repairment effects of plant reclamation with advantages have on arsenic polluted soil were studied by field survey and planting experiments.This thesis illuminates that the coal species in study area is long flame coal,of which the average arsenic content is 9.185?g/g.Different modes of arsenic in coal are in the order of residues(41.96%)>sulfide binding state(31.01%)>organic combination(24.19%)>water soluble state(2.65%),while in soil are in the order of O-As(60.75%)>Ca-As(14.49%)>Fe-As(9.97%)>A1-As(6.64%)>A-As(1.50%)>H2O-As(0.26%).The arsenic pollutants in soil are mainly derived from valid state arsenic in coal,which account for 34.61%of the total arsenic amount.They damage the soil by dumping of coal gangues,leaching,weathering and fly ash diffusion from coal fire power plant.In alkaline soil ecosystem arsenic obviously restrains the growth of microbial communities,such as Caulobacter and Firmicutes.Cystobacteraceae(sp.)is peculiar to enduring arsenic.Green bristlegrass is the main optimization of the mining area land reclamation plant species.With the green bristlegrass repairment,arsenic content is soil decreases to 81.6%at most while enrichment factor is 0.77 and transfer ratio is 1.5 at most.The study results have quite important theoretical significance and application value in arsenic pollutant source analysis,risk evaluation and soil ecosystem repairment.