郑州市土壤与绿色植物中汞的分布特征

Concentration and Distribution of Mercury in Soil and Plant Leaves in Zhengzhou City

汞污染具有生物积累性,因而得到社会广泛关注。研究监测和评估了郑州市城区土壤和绿色植物叶片中汞浓度、分布、污染水平等。研究发现郑州市主城区土壤总汞浓度为0. 150～0. 958 mg/kg,平均浓度为0. 448 mg/kg;郑州市主城区绿色植物叶片总汞浓度为0. 017～0. 249 mg/kg,平均浓度为0. 107 mg/kg;土壤和叶片中汞浓度按功能区排序为交通枢纽区>工业区>商业区>行政区>高教区>住宅区。采用地累积指数法对郑州市80个土壤样品的汞污染水平进行评估,结果显示60%受到轻度污染,35%受到偏中度污染,5%受到中度污染。研究较为全面地分析了土壤汞污染的现状及浓度,为郑州市土壤汞污染防治提供参考。

Mercury pollution of soil is irreversible and undergoes bioaccumulation, and it should therefore receive greater focus. Comprehensive measurements of mercury in soil and plant leaves in urban Zhengzhou were conducted to determine the concentration, distribution, and pollution levels. Mercury concentrations in soil ranged from 0.150 to 0.958 mg/kg, with a mean value of 0.448 mg/kg. Mercury concentrations in the leaves of urban green plants ranged from 0.017 to 0.249 mg/kg, with a mean value of 0.107 mg/kg, which are moderate levels for China. Furthermore, the soil and leaf mercury concentrations in six functional areas of the main urban area of Zhengzhou were investigated, which were decreased in the following order:traffic, industrial, commercial, administrative, higher education, and residential. Finally, soil mercury contamination in urban areas was evaluated by using the geoaccumulation index method, and the results showed that 60% of the 80 soil samples experienced mild pollution, 35% of the samples experienced partial moderate pollution, and 5% of the samples experienced moderate pollution. This study creates a more comprehensive understanding of the present status and the concentration of soil mercury pollution, and provides a basis for the control of soil mercury pollution in Zhengzhou city.