中文摘要：

该文采集典型工业区土壤及植物样品,研究了典型工业区土壤中重金属污染程度、污染分布,并进一步分析了土壤中重金属污染特征及潜在生态风险。研究结果表明,研究区域表层土壤中中重金属含量依次从高到低为：Pb〉Zn〉Cr〉Cu〉Cd,平均含量分别为113.25、92.15、78.63、44.31和0.32 mg/kg。重金属含量均超过兰州市土壤背景值,其中毒性较强的重金属Pb的平均含量超过土壤背景值的5倍,但各采样点土壤中5种重金属的含量均低于土壤环境质量二级标准。土壤重金属纵向分析显示,随土壤深度增加,重金属含量降低,且污染物主要富集在表层0～20 cm。土壤重金属污染特征分析结果表明工业活动及交通对典型工业区的土壤Pb、Cd含量影响较大.采用地积累指数法对土壤质量进行评价,结果显示研究区域内土壤受到Cu、Zn、Pb、Cr轻-中度污染,受到Cd严重污染。土壤中重金属可提取态分析表明,典型工业区土壤中的Zn、Cd及Cu易于通过土壤-植物系统发生迁移,而Pb和Cr比较稳定,不容易发生迁移。植物样品分析结果表明植物中Zn含量较高,植物对重金属的富集能力从高到低依次为Zn〉Cu〉Cr〉Pb。

英文摘要：

Soil and plant samples were collected in typical industrial district in Lanzhou, Gansu Province. The levels, spatial distribution and potential ecological risk of heavy metals were investigated. In the surface soils collected from typical industrial district, the mean concentrations of lead （Pb）, chromium （Cr）, zinc （Zn）, copper （Cu） and cadmium （Cd） were ] 13.25, 92.15, 78.63, 44.31 and 0.32 mg/kg respectively. The concentrations of individual heavy metal were higher than the background value and the concentrations of heavy metals in topsoil showed a trend in an order of Pb 〉Cr 〉Zn 〉Cu 〉Cd. Moreover, the concentration of heavy metals decreased with the depth of soil. Through description of spatial variation of heavy metals in different areas, industrial activities and transports were the important sources of heavy metal pollution in soil in the study area. The geo-accumulation index （1～） was adapted to evaluate the. pollution status and the soil quality contaminated by heavy metals in the study area. Results showed that the soil was moderately polluted by Cu, Zn, Pb and Cr, but the soil was severely polluted by Cd. The available contents of heavy metals in soils showed that Zn, Cd and Cu element were easy to accumulate from soil to plant, but Pb and Cr element were hard to be uptaken by plants. The analytical results showed that higher Zn contents were detected in plants, and the enrichment ability of heavy metals in plants from high to low was Zn〉Cu〉Cr〉Pb.