基于不同土地利用方式的深圳市农用地土壤重金属污染评价

Evaluation of the Heavy Metal Pollution in Different Agricultural Soils of Shenzhen City

为探讨深圳市农林土壤重金属的污染现状,分菜地、果园、林地和荒地等4种不同的土地利用类型,共采集了52个表层土壤样品,采用原子吸收法测定了其重金属Cu、Pb、Zn、Cd、Cr和Ni全量,单项污染指数法和内梅罗综合指数法评价了6种重金属在土壤中的污染现状.评价结果显示,部分土壤样点存在较为严重的重金属污染,Cd的污染最为严重,Cu的污染最轻;不同用地类型下的污染等级不同,荒地处于尚清洁(警戒限)水平,菜地和林地处于轻度污染水平,果园处于中度污染水平,全市农用地土壤处于轻度污染水平.

In order to analyze the content of agricultural surface soil and evaluate the hazard of heavy metals（Cu,Pb,Zn,Cd,Cr and Ni）in such field in Shenzhen,a survey was conducted.Twelve,twenty three,fifty,and two soil samples were collected from vegetable land,fruit land,wood land,and grass land,respectively.Pollution situation of the six heavy metals were evaluated using single contamination index method and Nemerow composite index.Results showed that serious heavy metal pollution was found in some soil samples.The pollution of Cd was most serious and Cu was slightest.There were different heavy metal pollution levels in different land-use types.The grass land was at good level,vegetable land and wood land were slightly polluted,and fruit land was moderately polluted.On the whole,the agricultural surface soils of Shenzhen were at slight pollution level.