典型旅游城市土壤重金属特定源生态风险评价及优先控制源分析  

Identification Priority Source of Heavy Metals in Urban Soils Based on Source-specific Ecological Risk Analysis in a Typical Tourist City

作　　者：李军 高占栋[1] 台喜生 焦亮[2] 臧飞 LI Jun;GAO Zhan-dong;TAI Xi-sheng;JIAO Liang;ZANG Fei(College of Urban Environment,Lanzhou City University,Lanzhou 730070,China;Key Laboratory of Resource Environment and Sustainable Development of Oasis,Gansu Province,Northwest Normal University,Lanzhou 730070,China;College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China)

机构地区：[1]兰州城市学院城市环境学院,兰州730070 [2]西北师范大学甘肃省绿洲资源环境与可持续发展重点实验室,兰州730070 [3]兰州大学草地农业科技学院,兰州730020

出　　处：《环境科学》2024年第8期4837-4846,共10页Environmental Science

基　　金：甘肃省绿洲资源环境与可持续发展重点实验室开放课题项目(GORS202102);甘肃省科技计划项目(21JR1RA319);甘肃省高等学校科研项目(2023A-116)。

摘　　要：为了解西北旅游城市土壤重金属的污染现状、分布特征及污染来源,选择敦煌市主城区土壤为研究对象,采集并分析了表层土壤重金属As、Cd、Cr、Cu、Hg、Ni、Pb和Zn的含量特征.采用地累积指数法和改进内梅罗污染指数法量化土壤重金属污染水平,利用聚类分析和正定矩阵因子分解(PMF)模型定量解析重金属污染来源,并应用PMF模型和综合生态风险指数相结合的方法解析各污染源对生态风险的贡献率.结果表明,除As和Ni之外,Cd、Cr、Cu、Hg、Pb和Zn含量的均值均高于甘肃省土壤元素背景值,但所有元素的含量均低于《土壤环境质量建设用地土壤污染风险管控标准(试行)》(GB 36600-2018)中建设用地的风险筛选值,其中Cd、Pb和Hg的富集较为严重,超标率均高于90%.地累积指数评价结果显示,研究区土壤以Hg污染为主,也存在不同程度的Cd、Cr、Cu、Pb和Zn污染.改进内梅罗污染指数结果表明,土壤的综合污染程度为无污染至中度污染,总体上为轻度污染.PMF模型源解析表明,研究区土壤重金属受自然源、工业降尘源、工业源、交通源和综合源的影响,贡献率依次为29.28%、25.86%、20.13%、16.5%和8.23%.特定源-综合生态风险评价模型分析表明,工业降尘源为优先控制污染源,Hg为生态风险优先控制污染元素.To understand the pollution status,distribution characteristics,and pollution sources of soil heavy metals in tourist cities in northwest China,the soil content of heavy metals As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn in the main areas of Dunhuang City was collected and analyzed.The soil heavy metal pollution level was quantitatively evaluated by the methods of the geo-accumulation index and improved Nemerow pollution index,and the sources of heavy metal pollution were quantitatively analyzed using cluster analysis and the positive matrix factorization(PMF)model.The contribution rate of each pollution source to ecological risk was determined by combining the PMF model and comprehensive ecological risk index.The results showed that except for the mean contents of As and Ni,the mean contents of Cd,Cr,Cu,Hg,Pb,and Zn were all higher than the background values in Gansu Province.However,the average content of the eight elements was lower than the screening value of construction land in the Standard for Soil Pollution Risk Control of Soil Environmental Quality Construction Land(trial)(GB 36600-2018).Among them,the enrichment of Cd,Pb,and Hg was more serious,and the exceedance rate was higher than 90%.The results of the geo-accumulation index indicated that urban soils were mainly polluted by Hg in the study area,and Cd,Cr,Cu,Pb,and Zn pollution also existed in different degrees.The improved Nemerow pollution index illustrated that the comprehensive pollution degree of the soil was clean to moderate pollution,and the overall pollution was light pollution.Based on the PMF model,we could conclude that soil heavy metals in the study area were affected by natural sources,industrial deposition sources,industrial sources,traffic sources,and comprehensive sources,and the contribution rates were 29.28%,25.86%,20.13%,16.5%,and 8.23%,respectively.The specific source-integrated ecological risk assessment model found that the industrial deposition source contributed the most to the ecological risk in the study area and could be regarded as the

关 键 词：城市土壤 地累积指数 污染评价 生态风险 溯源解析 

分 类 号：X53[环境科学与工程—环境工程] X825