某卫生垃圾填埋场周边土壤和植物的重金属污染现状

Current situation of heavy metal pollution in the soil and vegetation around a landfill

目的了解某卫生垃圾填埋场对其周边土壤和植被的重金属污染状况。方法以某市卫生垃圾填埋场为研究对象,根据其所处地区的主导风向,参照HJ/T 166-2004《土壤环境监测技术规范》分别采集其周边的土壤样品及生长区域内的植物样品,并对其重金属含量进行分析测定。结果垃圾卫生填埋场场界土壤中重金属镉、砷、铜、铅、铬、锌、镍的含量均低于GB 15618-1995《土壤环境质量标准》中的Ⅱ类标准中的土质环境质量标准限值,但垃圾场南侧土壤样品金属汞的含量超过Ⅱ级标准,进一步的分析结果显示:不同风向区域的土壤和植被样品中的镉、汞、砷、铜、铅、铬、锌等重金属含量存在显著性差异,下风向含量明显高于上风向。结论垃圾填埋场周边地区土壤存在重金属汞的污染,并且污染程度与风向有一定的关系。

[Objective]To study the status of heavy metal pollution in the soil and vegetation around a landfill.[Methods]A landfill site was selected as the research object.Based on the dominant wind direction,soil and vegetation samples around the landfill has been collected according to the Technical Specification of Soil Environmental Monitoring（HJ/T 166-2004）,and the levels of heavy metals in all samples were measured and analyzed.[Results]The levels of cadmium,arsenic,copper,lead,chromium,zinc and nickel in the soil around the landfill sites were lower than the limit values of national gradeⅡ standard from the Soil Environmental Quality Standards（GB 15618-1995）.On the contrary,the level of metallic mercury in the soil samples from the south of the landfill was higher than that of grade Ⅱ standard.There were significant differences in levels of cadmium,mercury,arsenic,copper,lead,chromium and zinc in the soil and vegetation between different wind zones,and the levels of downwind side were significantly higher than those of upwind side.[Conclusion]It is revealed that there exist mercury pollution in soil around the landfill,and pollution level is related to wind direction.