煤矸石场附近3种粮食作物的重金属富集特征及污染评价  

Enrichment characteristics and contaminant assessment of heavy metals in three food crops around the gangue dumps

作　　者：李琦[1] 韩亚芬[1] 许东升[1] 高杨[1] 

机构地区：[1]宿州学院地球科学与工程学院,安徽宿州234000

出　　处：《安全与环境学报》2014年第5期321-326,共6页Journal of Safety and Environment

基　　金：宿州学院教授(博士)科研启动基金项目(2013JB01);宿州学院安徽省煤矿勘探工程技术研究中心开放课题(2013YKF05;2013YKF06;2013YKF07;2012YKF15)

摘　　要：为深入认识煤矸石堆积对周围农作物的重金属污染危害,探讨矸石场附近土壤-作物系统中重金属元素的富集转运规律,以宿州桃园煤矿矸石场附近农田为例,通过布点采样和试验测定,探讨了重金属元素Cu、Pb、Cd和Cr在土壤和3种粮食作物(玉米、绿豆和大豆)中的质量比分布特征,对比分析了不同粮食作物的根部富集能力和籽实转运能力,并利用单因子及内梅罗污染指数法对农作物重金属污染状况进行了评价。结果表明:研究区土壤中Cd、Cr和Cu有明显积累,4种元素质量比均随与矸石场距离增加而逐渐下降;作物不同器官中重金属质量比从大到小为根、茎、籽实,但叶片中部分元素质量比明显偏高;作物根部对重金属元素的吸收能力以玉米最高,而向籽实中的转运能力以绿豆和黄豆最高,这主要是3种作物根系特征和秸秆高度的差异所致;3种作物的内梅罗污染指数从大到小为玉米、黄豆、绿豆,其中玉米为轻度污染,黄豆和绿豆处于警戒水平。This paper aims to make a study of the distribution patterns, the enrichment characteristics and the corresponding contamination conditions caused by the heavy metal contents in the soil and corps （corn, mung and soybean） around the gangue dump. For this purpose, we have collected 36 soil and 42 crops samples from the farm lands around the gangue dump of Taoyuan coal mine. And then we have made an analysis of the distributive features of Cu, Pb, Cd, Cr in the soils and corps, with a contrastive analysis done with the enrichment features of the root and the transfer ability of the seeds a- mong the three crops. In order to evaluate the pollution condition of the three corps, it is necessary to use the atomic absorption spec- trophotometry （AAS）, the single factor index and the Nemero comprehensive index. The results of our investigation indicate that： the chemical contents of Cu （47.76 mg/kg）, Cd （0.47 mg/kg） and Cr （125.30 mg/kg） have been found higher than the background value of the soil elements and the preliminary standards of the soil environment quality, though Pb （15.28 mg/kg） was in the reverse. However, with the increase of the distance away from the gangue dump, heavy metal content concentrations in the soil tend to decrease gradually. For example, the rate of the content decrease from 50 m to 500 m is in the degrading order of Cr （40.92%）, Pb （34.14%）, Cd （30.13%） and Cu （20.44%）, which reveals the migration features of the different elements. What is more, the remnant concentrations of Cu, Pb, Cd and Cr in the different plant organs are also in the degrading order of root 〉 stem 〉 seed, but that of Pb in the leaves turns to be significantly higher. What is more, the absorptive ability of the corn roots for the heavy metals proves to be higher than mung and soybean whereas the seed transfering ability turns to be reversed, for such differences account for the different root features and the stalk heights of the three crops. And, last of all, the Nemero comp

关 键 词：环境学 煤矸石场 粮食作物 重金属 富集特征 污染评价 

分 类 号：X56[环境科学与工程—环境工程]