| 粤北典型工矿区土壤重金属富集特征、来源解析及风险评价 |
| 摘要点击 1677 全文点击 517 投稿时间：2022-04-23 修订日期：2022-06-02 |
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| 中文关键词 土壤重金属 空间分布 来源分析 地累积指数 潜在生态风险 |
| 英文关键词 heavy metals spatial distribution source analysis index of geo-accumulation potential ecological risk |
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| 中文摘要 |
| 为了解粤北典型工矿区土壤重金属污染状况，以研究区的表层土壤（0~20 cm）为研究对象，在测定209个样点土壤重金属（As、Cd、Cr、Cu、Hg、Ni、Pb和Zn）含量的基础上，运用GIS和主成分分析法解析8种土壤重金属来源和空间分布特征，并采用地累积指数法和潜在生态危害指数法系统评估其污染状况和生态风险.结果表明：①除Ni以外，其余7种元素均超过全国土壤背景值，但低于污染风险筛选值，土壤环境整体较为清洁.②土壤重金属空间分布各异，As和Pb含量呈现西北-东南向条带状分布，Cd、Cu、Hg和Zn含量在研究区总体上呈中部向四周同心圆状递减分布，与工矿企业位置基本吻合，而Cr和Ni含量的空间分布与工业企业等污染源的位置没有直接关系.③8种元素可辨识为3个主成分，PC1（Cd、Cu、Pb和Zn）主要受铅锌矿选冶、交通排放和农业生产等人类活动影响；PC2（Cr和Ni）属自然来源，主要受成土母质影响；PC3（As和Hg）主要受有色金属冶炼和火力发电等工业活动影响.④通过地累积指数法发现，8种重金属风险程度依次为：Cd>As>Zn>Hg>Pb>Cu>Cr=Ni，其中土壤Cr和Ni含量处于无风险水平，As、Cu、Hg、Pb和Zn含量处于中低风险水平，而Cd含量处于高风险水平.研究区内单元素潜在生态危害大部分处于轻度风险等级，少部分工业活动密集区的表层土壤受到强等级的重金属胁迫，需要引起警惕. |
| 英文摘要 |
| In order to understand the heavy metal pollution of the industrial and mining area in northern Guangdong Province, topsoil samples (0-20 cm) from 209 sites in study area were collected, and the concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were analyzed. The source and distribution characteristics of Cd, Cr, Hg, Ni, Pb, As, Cu, and Zn in soil samples were analyzed using the geographic information system (GIS) and principal component analysis (PCA), and the geo-accumulation index and potential ecological hazard index were used to evaluate their pollution status and ecological risk. The results showed that:① Except Ni, all seven heavy metal elements exceeded the national soil background value but were below the pollution risk screening value. The soil environment as a whole was relatively clean. ② The spatial distribution of heavy metals in soil differed. The contents of As and Pb showed northwest-southeast zonal distribution. The contents of Cd, Cu, Hg, and Zn generally decreased from the middle to the surrounding, which was consistent with the industrial and mining enterprise locations. However, the spatial distribution of Cr and Ni had no direct relationship with the location of pollution sources such as industrial enterprises. ③ The eight heavy metals could be identified as three principal components (PCs). PC1 (Cd, Cu, Pb, and Zn) was mainly affected by human activities such as lead-zinc deposit dressing, traffic emissions, and agricultural production. However, PC2 (Cr and Ni) was a natural source, mainly affected by soil parent material. In addition, PC3 (As and Hg) was mainly affected by industrial activities such as non-ferrous metal smelting and thermal power generation. ④ According to the geo-accumulation index method, the risk degree of the eight heavy metals was:Cd>As>Zn>Hg>Pb>Cu>Cr=Ni. The contents of Cr and Ni in soil were at a no-risk level; the contents of As, Cu, Hg, Pb, and Zn were at a low-risk level; and the content of Cd was at a high-risk level. Most potential ecological hazards for single elements in the study area were at a mild risk level. In contrast, a small proportion of the surface soils in areas of intense industrial activity were subject to substantial levels of heavy metal stress and require further attention. |
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