| 摘要: |
| 准确识别重金属污染源并开展生态风险评估，是历史遗留矿区污染防控与治理的关键。本研究以广西北部某历史遗留铅锌集中开采区为对象，通过系统采集矿区周边土壤、下游农田土壤及河流底泥样品，分析了砷（As）、镉（Cd）、铬（Cr）、铜（Cu）、汞（Hg）、镍（Ni）、铅（Pb）、锑（Sb）、铊（Tl）、锌（Zn）10种重金属的含量与空间分布特征，其中底泥样品用于揭示重金属从矿区向下游农田的迁移路径。运用Nemerow综合污染指数、地累积指数和潜在生态风险指数开展污染与风险评估，并结合APCS-MLR和PMF模型进行污染源解析，量化污染贡献度。结果表明，研究区域的土壤重金属均有不同程度富集，矿区周边土壤10种重金属平均值均高于广西土壤背景值，下游农田土壤Cd、Cu、Hg、Pb和Zn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，超标率分别为100%、60%、40%、90%和100%。Cd、Pb、Zn为主要污染元素，呈现重度污染及高生态风险水平，而Sb和Hg的生态风险也不容忽视，研究区域整体处于极高生态风险水平。通过APCS-MLR与PMF模型联合解析，识别出四种主要污染来源：矿山采选活动是Cd和Zn的主要来源；农业活动与交通运输复合源对Cu、Hg、Pb贡献显著；Cr、Ni、Tl以成土母质自然来源为主；Sb可能来源于长期缓慢释放的工业废渣源等未知源，As呈现多源复合污染特征。研究结果揭示了该铅锌矿区土壤重金属的复合污染特征与多源性贡献，可为矿区环境污染防控与区域修复治理提供科学指导。 |
| 关键词: 历史遗留铅锌矿区 土壤重金属 农田 底泥 风险评估 源解析 |
| DOI： |
| 投稿时间：2026-02-27修订日期：2026-06-18 |
| 基金项目:中央引导地方科技发展资金项目（桂科 ZY24212039），国家重点研发计划项目（2025YFC3715200），广西环科院科研创新基金项目（HT-202511015）资助。 |
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| Characteristics, Risk Assessment and Source Apportionment of Heavy Metal Pollution in Soils from a Lead-Zinc Mining Area, Northern Guangxi |
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| Abstract: |
| Accurate identification of heavy metal pollution sources and ecological risk assessment is the key to pollution prevention, control and remediation in historical mining areas. This study focuses on a historically lead-zinc mining area in northern Guangxi Province, systematically collected samples of soil around the mining area, farmland soil in the downstream areas and river sediment, and analyzed the content and spatial distribution of 10 heavy metals including As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Tl and Zn. The sediment samples were used to reveal the migration pathways of heavy metals from the mining area to downstream farmland. The Nemerow comprehensive pollution index, geo-accumulation index and potential ecological risk index were applied to evaluate the heavy metal pollution level. The pollution source apportionment was analysed by combining the APCS-MLR and PMF models, and the contribution degree of pollution was quantified. The results indicated that heavy metals were enriched to varying degrees in the soils of the study area. The average contents of the 10 heavy metals in the soils around the mining area all exceeded the soil background values of Guangxi. The contents of Cd, Cu, Hg, Pb and Zn in the farmland soils in the downstream areas surpassed the risk screening values specified in Soil environmental quality Risk control standard for soil contamination of agricultural land (Trial) (GB 15618-2018), with the over-standard rates reaching 100%, 60%, 40%, 90% and 100%, respectively. Cd, Pb and Zn were identified as the primary pollutant elements, exhibiting severe pollution and a high ecological risk level, while the ecological risks of Sb and Hg should also not be neglected. Overall, the entire study area is at an extremely high ecological risk level. Combined source apportionment via the APCS-MLR and PMF models identified four primary pollution sources: mining and beneficiation activities accounted for the primary contributions of Cd and Zn; a mixed source of agricultural activities and transportation made significant contributions to Cu, Hg and Pb; Cr, Ni and Tl originated predominantly from natural soil parent material sources; Sb was likely associated with unknown sources, such as industrial waste residues with long-term slow release, while As displayed the characteristics of multi-source combined contamination. This study reveals the characteristics of combined heavy metal contamination and multi-source contributions in the soils of the Pb-Zn mining area, thereby providing scientific support for pollution prevention, control and ecological remediation in the mining area. |
| Key words: Historical mining areas Soil heavy metals Farmland Sediment Risk assessment Source analysis |
