【摘要】 为深入分析工业城市土壤重金属污染的影响因子及来源途径,本文以宝鸡市区采集的62份表层（0～20 cm）土壤样品为研究对象,使用电感耦合等离子体质谱仪（ICP-MS）测定重金属（Cd、As、Cu、Pb、Zn、Cr、Mn和Ni）含量,基于地统计方法及地理探测器模型,以土壤重金属污染负荷指数（PLI）为主导指标,探测土壤重金属污染的影响因子,并使用Unmix6. 0受体模型进行重金属源解析.结果表明:①宝鸡市区表层土壤重金属Cd、Pb、Cu、Zn、As、Cr、Mn和Ni含量均值分别为0. 77、16. 75、40. 52、261、17. 03、49. 18、331和30. 52 mg·kg^-1,其中Cd和Zn均值超过了国家二级标准,是陕西省土壤背景值的8. 2倍和3. 8倍,Cu、As和Ni均值也超过了陕西省土壤背景值,Cd和Zn在城区土壤中存在重度污染现象.②宝鸡市区表层土壤重金属区域总污染负荷指数(PLI_zone)达1. 36,为轻度污染,经地理探测器分析,土壤质地和铁路距离对污染分布的解释力最强,P_D,H分别为0. 040和0. 026,交互解释力均达0. 099.③Cd、Cu和As主要为工农业活动所致的"人为源",Zn和Ni为交通排放造成的"人为源",Cr、Pb和Mn主要为"混合源".研究区表层土壤重金属主要来源为"混合源",为轻度污染级,土壤质地和距铁路距离是土壤重金属污染的主要影响因子.本研究可以为宝鸡市土壤重金属污染与防治提供科学依据.更多还原

【Abstract】 In order to analyze the sources and factors influencing heavy metal pollution in industrial cities,62 surface layer（ 0-20 cm）soil samples were collected in Baoji City for analysis using inductively coupled plasma mass spectrometry（ ICP-MS）. Cd,As,Cu,Pb,Zn,Cr,Mn,and Ni were detected in the samples. Based on geostatistical methods and geo-detector models,the soil heavy metal pollution load index（ PLI） was selected as the best indicator of factors affecting heavy metal pollution. The Unmix 6. 0 receptor model was also used to analyze the heavy metal source. The results showed that: ① The average concentrations of Cd,Pb,Cu,Zn,As,Cr,Mn,and Ni in the surface soils of Baoji City were 0. 77 mg·kg^-1,16. 75 mg·kg^-1,40. 52 mg·kg^-1,261 mg·kg^-1,17. 03 mg·kg^-1,49. 18 mg·kg^-1,331 mg·kg^-1,and 30. 52 mg·kg^-1,respectively. These values exceeded the national secondary standard for Cd and Zn,which were 8. 2 and 3. 8 times more abundant,respectively,than in the background soils of Shaanxi Province,indicating that urban soils are seriously polluted with Cd and Zn. The average concentrations of Cu,As,and Ni also exceeded the background levels;② The total pollution load index (PLI_zone) for heavy metals in the surface soils of Baoji City was 1. 36,which indicated mild levels of pollution,as analyzed using a geo-detector. Soil texture and distance to the city’s railway had the strongest explanatory power for the distribution of pollutants (P_D,H= 0. 040 and 0. 026,respectively,with a combined explanatory power of 0. 099); ③ Cd,Cu,and As mainly derive from "artificial sources " associated with industrial and agricultural activities,and Zn and Ni derive from traffic emissions. Cr,Pb,and Mn mainly derive from"mixed sources". Overall,the main source of heavy metals in the surface soils of the study area was classified as"mixed source"and soils were classified as having a mild level of pollution. These results provide scientific support for the prevention and control of heavy metal pollution in the soils of Baoji City.更多还原