千河下游土壤-小麦系统重金属富集特征及风险评价  

Enrichment characteristics and risk assessment of heavy metals in the soil-wheat system in the lower reaches of the Qianhe river

作　　者：王国兰 王玥 李旭 耿雅妮[1] WANG Guolan;WANG Yue;LI Xu;GENG Yani(Baoji University of Arts and Sciences,Shaanxi Key Laboratory of Disaster Monitoring and Mechanism Simulation,Baoji 721013,China)

机构地区：[1]宝鸡文理学院陕西省灾害监测与机理模拟重点实验室,宝鸡721013

出　　处：《干旱区资源与环境》2022年第4期80-86,共7页Journal of Arid Land Resources and Environment

基　　金：旱区地下水文与生态效应教育部重点实验室(长安大学)开放基金项目(300102290504);陕西省教育厅重点实验室项目(20JS010)资助。

摘　　要：为探讨千河下游土壤-小麦系统中重金属富集特征及土壤污染风险,采集千河下游土壤和小麦籽粒各28份,使用ICP-MS测定8种重金属(As、Cd、Cr、Cu、Mn、Ni、Pb和Zn)含量,采用污染负荷指数对土壤重金属污染风险进行分析,并运用GIS空间化和生物富集系数相结合的方法揭示研究区土壤-小麦系统重金属之间富集关系。结果表明:土壤重金属含量均值顺序为Mn>Zn>Ni>Cr>Cu>As>Pb>Cd,As超过《土壤环境质量-农用地土壤污染风险管控标准》(GB 15618-2018)的风险筛选值;小麦重金属平均含量顺序为:Zn>Mn>Cr>As>Cu>Ni>Pb>Cd,小麦籽粒中As超过了食物中重金属安全限值标准(GB 2762-2017);土壤重金属高值区集中于东南部区域、铁路干线和宝凤高速交叉区域。小麦中重金属空间分布差异显著,As高值区位于张家寨村和千河镇;重金属富集系数顺序为:Zn>Pb>Cd>As>Cr>Cu>Mn>Ni,Zn属于中度富集,Pb、Cd和As处于轻度富集;土壤重金属PLI污染负荷指数介于0.536~1.432之间,PLI_(zone)为0.94,属于轻度污染。In order to explore the characteristics of heavy metal accumulation and soil pollution risk in the soil-wheat system in the lower reaches of the Qianhe river,28 samples for each of which contains the soil and wheat grains in the lower reaches of the Qianhe river were collected.The inductively coupled plasma mass spectrometer(ICP-MS)was used to determine the content of 8 heavy metals(As,Cd,Cr,Cu,Mn,Ni,Pb and Zn),the pollution load index was used to analyze the risk of soil heavy metal pollution,and the method of combining GIS spatialization and bioconcentration coefficient was used to reveal the enrichment relationship of heavy metals in the soil-wheat system in the study area.The results showed that the average order of soil heavy metal content is:Mn>Zn>Ni>Cr>Cu>As>Pb>Cd.As exceeds the risk screening of"Soil Environmental Quality-Agricultural Land Soil Pollution Risk Control Standard"(GB 15618-2018)value.The order of the average content of heavy metals in wheat is:Zn>Mn>Cr>As>Cu>Ni>Pb>Cd.The As content in wheat grain exceeds the safety limit of heavy metals in food(GB 2762-2017).The high value areas of heavy metals in soil are concentrated in the southeast area,the main railway line and the intersection of Baofeng Expressway.There are significant differences in the spatial distribution of heavy metals in wheat.The high As value areas are located in Zhangjiazhai village and Qianhe town.The order of the enrichment coefficient of heavy metals is:Zn>Pb>Cd>As>Cr>Cu>Mn>Ni.Zn is moderately enriched,Pb,Cd and As are slightly enriched.The soil heavy metal PLI pollution load index is between 0.536 and 1.432,and the PLIzone is 0.94,which is a slight pollution.

关 键 词：小麦 重金属 富集系数 风险评价 千河 

分 类 号：X53[环境科学与工程—环境工程]