【作者】 刘宝勇；

【导师】 白润才；

【作者基本信息】 辽宁工程技术大学 ， 矿山环境工程， 2016， 博士

【摘要】 煤炭在开采、加工、运输和利用过程中,所含污染物砷进入到土壤、大气和水体环境,并发生迁移和转化,对矿区生态系统构成威胁。研究煤炭开采及利用过程中砷向环境的迁移转化特征及砷污染对矿区土壤生态系统的影响是矿区生态环境恢复与重建的前提,为进一步解决砷污染技术问题提供理论依据。论文以内蒙古大柳塔煤矿中等含砷煤及受砷污染土壤生态系统为研究对象,采用现场调查取样、实验室研究、现场种植试验、理论分析等手段与方法,对大柳塔煤矿土壤砷污染特征及修复效应问题进行了系统研究。采用电子显微和X射线衍射等技术对煤样的矿物组成进行了分析,研究区煤种为长焰煤,平均含砷量9.185μg/g;采用微波消解-原子荧光光谱法对研究区煤及土壤中砷的含量和赋存形态进行表征,煤中砷的各形态含量依次为残渣态(41.96%)>硫化物结合态(31.01%)>有机结合态(24.19%)>水溶态(2.65%);土壤中砷的各形态含量依次为O-As(60.75%)>Ca-As(14.49%)>Fe-As(9.97%)>A1-As(6.64%)>A-As(1.50%)>H20-As(0.26%);通过源解析研究大柳塔煤矿土壤砷污染特征,大柳塔煤矿土壤砷污染主要来源于煤中有效态砷,通过矸石的堆放、淋溶与风化及燃煤电厂飞灰扩散等途径污染土壤,土壤有效态砷含量占总砷含量的34.61%;利用PCR-DGGE技术,对矿区土壤微生物群落进行丰度和数量研究,在矿区偏碱性土壤生态系统条件下,砷对Caulobacter(柄杆菌属)、Firmicutes(厚壁菌门)等微生物群落抑制明显,Cystobacteraceae(sp.)(孢囊杆菌科菌株)等为特有耐砷微生物群落;通过野外调查、种植试验等,研究了土壤中砷对植物多样性的影响及优势复垦植物对砷污染土壤的修复效应,研究区土壤生态修复的优势植物以狗尾草为主,经狗尾草修复后,土壤中砷含量去除率最高可达81.6%,狗尾草对砷的富集系数最高为0.77,对砷的转移系数最高为1.5。研究成果对煤矿区砷污染源解析、风险评价及土壤生态修复具有一定的理论意义和应用价值。更多还原

【Abstract】 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 9.185μg/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.更多还原