| 重庆某铁矿区周边耕地土壤重金属污染评价及来源解析 |
| 摘要点击 810 全文点击 151 投稿时间：2023-05-17 修订日期：2023-07-04 |
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| 中文关键词 铁矿区 土壤 重金属 风险评价 源解析 |
| 英文关键词 iron ore mining area soil heavy metal risk assessment source apportionment |
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| 中文摘要 |
| 为了解重庆市南部某历史遗留铁矿区周边耕地土壤重金属污染状况及污染来源,在铁矿渣场周边采集了34个耕地表层土壤样品,分析了重金属Cd、Hg、As、Pb、Cr、Cu、Ni和Zn的含量,采用地累积指数和潜在生态风险指数对铁矿渣场周边耕地土壤污染进行评价,并利用主成分分析（PCA）和绝对主成分得分多元线性回归受体模型（APCS-MLR）识别铁矿区周边耕地土壤重金属的污染来源及贡献率.结果表明,研究区土壤除Cr外,其余重金属含量平均值均超过重庆市土壤背景值,且有20.6%的土壤点位Cd以及2.94%的土壤点位Hg、Cu和Ni超过《土壤环境质量农用地土壤污染风险管控标准（试行）》（GB 15618-2018）风险筛选值；地累积污染指数评价结果显示研究区土壤主要受Cd和Hg污染,呈现无污染到中度污染等级,并且Cd与Hg对潜在生态污染指数（RI）贡献率分别达到24.47%和60.33%.相关性分析与主成分/绝对主成分（PCA/APCS）受体模型分析结果表明,Cr、Cu、Ni和Zn主要来源于成土母质,Hg和Pb来源主要为化石燃料燃烧及交通运输,Cd和As主要来源于采矿冶炼、施用化肥等采矿工业活动及农业活动.研究区土壤重金属主要影响途径为大气沉降和河流洪水淹没及灌溉,土壤重金属的高值区主要集中在受大气沉降途径污染区域. |
| 英文摘要 |
| In order to understand the pollution status and sources of heavy metals in arable soils around a historical iron ore mine area in southern Chongqing, 34 surface soil samples were collected and analyzed for the heavy metals Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn, and the soil pollution in the farmland around the dumps was evaluated by using the geo-accumulation index and potential ecological risk index. Correlation analysis, principal component analysis （PCA）, and absolute principal component score multiple linear regression receptor model （APCS-MLR） were used to discuss the source and source contribution rate of soil heavy metal pollution in this area. The results showed that the average values of heavy metal contents in the soils of the study area, except for that of Cr, exceeded the background values of soils in Chongqing, and 20.6% of soil Cd and 2.94% of soil Hg, Cu, and Ni exceeded the risk screening values of the “Agricultural Land Soil Pollution Risk Control Standards” （GB 15618-2018）. The results of the geo-accumulation index showed that the soils were mainly polluted by Cd and Hg, ranging from no pollution to a moderate pollution level, and the contribution rates of Cd and Hg to the potential ecological risk index RI reached 24.47% and 60.33%, respectively. Correlation analysis and PCA/APCS receptor model analysis showed that Cr, Cu, Ni, and Zn mainly originated from soil-forming parent material； Hg and Pb sources were mainly from fossil fuel combustion and transportation； and Cd and As mainly originated from mining, industrial activities, and agricultural activities. Atmospheric deposition, river flooding, and irrigation were the main influence pathways of heavy metals in soil in the study area, and the high value areas of heavy metals in soil were mainly concentrated in the areas polluted by atmospheric deposition pathways. |
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