平朔露天煤矿复垦区土壤中多环芳烃分布特征、来源解析及风险分析

Polycyclic aromatic hydrocarbons(PAHs)in the topsoils of typical reclaimed area in Pingshuo opencast coal mine:Status,sources and risk

原煤的开采、储存、运输及其加工利用过程是多环芳烃（PAHs）污染的主要来源。由于缺乏相关系统调查数据，其对煤矿复垦区土壤环境质量的影响尚不明确。平朔煤矿复垦土地主要作为耕地利用，了解其PAHs污染状况直接关系粮食安全和人体健康。该研究通过野外实地调查，开展了平朔煤矿复垦区表层土壤中多环芳烃（PAHs）的毒性风险分析研究。在整个平朔煤矿45km。范围内，以500m×500m间距为基准，按照不同用地类型，采集了0～20cm深度土壤样品179个，再按照1km×1km单元格组合后分析。使用安捷伦高分辨气相色谱一低分辨质谱进行目标物的检测。加入代用标准2一氟联苯（2-FBP）以进行回收率控制。研究结果表明：土壤中16种EPA-PAHs的含量范围为213．60～2513．20ng·g-1，均值为717．09ng·g-1.PAHs成分特征显示主要以3～4环为主（52％），5～6环次之（42％），2环所占比例最低（6％）。使用相关分析法判定，主要污染来源为原煤。毒性风险分析结果显示，平朔煤矿土壤PAHs存在一定生态风险，当土地重新作为农田加以利用时，需要加以关注。

Coal mining, storage, transportation and processing process is the main source of polycyclic aromatic hydrocarbons （PAHs） pollution, but its influence on soil environmental quality of opencast coal mine reclamation area is not clear, because of the lack of the systematic survey. Pingshuo opencast coal mine reclamation area is mainly used as cultivated land. Understanding its PAHs pollution condition is important to food security and human health. Through the field survey, this study conducted an ecological risk assessment of PAHs in soils. 179 surface soil samples （0 - 20 cm） were collected by 500 mX 500 m grid, then analyzed by 1 kmX 1 km compositional cell. Agilent high resolution gas chromatography- low resolution mass spectrometry （Agilent 6890 GC/5973i MS） were used for target detection and substitute standard 2-fluorine biphenyl （2-FBP） were added for recovery rate control. The total concentration of 16 EPA-PAHs ranged from 213.60 to 2513.20 ng/g with a mean value of 717. 09 ng/g. Individual composition of PAHs was of 52% for 3 - 4 rings, 42% for 5- 6 ring and 6~ for 2 ring respectively. A correlation analysis determined that the mainpollution source is coal. According to the results of ecological risk assessment, the reuse of reclamation land as cultivated land should be paid more attention on PAHs pollution in soils.