北京某环路两侧土壤重金属污染风险评价  

Evaluation of heavy metal pollution in the soil sampled from a ring road in Beijing

作　　者：许柏宁 王鹏[1] 王建壹[1] 王崇臣[1,2] 

机构地区：[1]北京建筑大学城市雨水系统与水环境省部共建教育部重点实验室,北京100044 [2]北京建筑大学北京应对气候变化研究和人才培养基地,北京100044

出　　处：《环境化学》2014年第12期2152-2161,共10页Environmental Chemistry

基　　金：环境科学与环境工程专业建设项目(PXM2013-014210-000157);北京市属高校高层次人才引进与培养计划和创新团队与教师职业发展计划-"青年拔尖人才培育计划(CIT&CD201404076);北京市优秀人才培养资助项目(2013D005017000004);北京建筑大学大学生科技研究项目

摘　　要：为了解北京市某环路两侧土壤重金属污染现状,对其22处采样截面的44个样品中的Cr、Ni、Cu、Zn、Cd和Pb总量进行测定,并用改进的BCR法对重金属形态进行分步提取和测定.结果表明,Cr、Pb和Cd的总量分别是北京地区土壤背景值的7.48、6.65和5.13倍;从提取形态来看,6种重金属主要以活性较低的还原态、氧化态和残渣态存在.采用4种评价方法从不同角度对研究区域土壤中重金属的污染风险进行了评价.基于总量的地累积评价结果显示,Cr、Pb和Cd污染级别最高,Ni、Cu和Zn次之;潜在生态风险指数法评价结果为Cd>Pb>Ni>Cr>Cu>Zn;基于形态学的评价方法 RAC风险评价法得到生物可利用性顺序为Zn>Cd>Ni>Cu>Pb>Cr;而次生相与原生相比值法的结论是生物潜在可利用性依次为Zn>Pb>Cd>Cu>Ni>Cr.In order to evalute the current soil pollution level of a ring road in Beijing,the total concentration of heavy metals including Cr,Ni,Cu,Zn,Cd and Pb in 44 soil samples collected from 22 sectors were determined,and the chemical species of these heavy metals were extracted with modified BCR method. The results showed that the average of total content of Cr,Pb and Cd were7. 48,6. 65 and 5. 13 times higher than their corresponding background concentrations in Beijing.Chemical species analysis revealed that these six heavy metals mainly existed as stable and inert forms like reducible,oxidizable and residual fractions. Additionally,four different methods were applied to evaluate the heavy metals pollution in the selected area. The results suggested that indexes of geo-accumulation based on total concentration were Cr 〉Pb〉 Cd 〉Ni〉 Cu〉 Zn; the potential ecological indexes were in the order of Cd,Pb,Ni,Cr,Cu and Zn. The risk assessment code based on chemical species implied that the potential bioavailability was in the order of Zn〉Cd〉Ni〉Cu〉Pb〉Cr,while the assessment based on the ratio of secondary phase and primary phase revealed their biological potential availability sequence was Zn〉Pb〉Cd〉Cu〉Ni〉Cr.

关 键 词：北京 土壤 重金属 风险评价 

分 类 号：X825[环境科学与工程—环境工程]