| 关中平原农田土壤剖面重金属空间分布、影响因素、风险评价及源解析 |
| 摘要点击 589 全文点击 74 投稿时间：2024-03-04 修订日期：2024-05-27 |
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| 中文关键词 农田 重金属 源解析 结构方程模型（SEM） 健康风险评价 |
| 英文关键词 farmland heavy metals source analysis structural equation modeling （SEM） health risk assessment |
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| 中文摘要 |
| 为了解关中平原农田土壤剖面（0~1 m）重金属空间分布、影响因素、生态风险特征和来源,采集关中平原124个样点0~1 m的土壤样品,分析了不同深度（0~10、10~20、20~40、40~60和60~100 cm）土壤重金属（As、Cd、Cr、Cu、Ni、Pb和Zn）的含量,基于地统计学生成了土壤重金属空间分布,基于结构方程模型研究了重金属的影响因素,基于地累积指数法、单因子污染指数法和潜在生态风险指数法评价了土壤重金属生态环境风险,基于PMF模型解析了土壤重金属的来源. 结果表明,研究区农田土壤0~10 cm ω（As）、 ω（Cd）、 ω（Cr）、 ω（Cu）、 ω（Ni）、 ω（Pb）和ω（Zn）平均值分别为19.57、0.71、69.65、21.91、28.67、17.54和73.77 mg·kg-1,As、Cd、Cr、Pb和Zn含量平均值均超过背景值,随深度的增加,除Ni和Cr外,其它均呈现降低的趋势. 空间分布表明,同一土层不同重金属空间分布不同,且不同深度重金属空间分布也不同. 结构方程模型显示,不同深度重金属分布的影响因素具有深度依赖性. 生态风险评估表明,不同深度的Cd具有较高生态风险,其余均属于轻微风险. 源解析显示,0~40 cm土层来源一致,主要来源为杀虫剂和除草剂、有机肥和化肥、自然源、交通导致的大气沉降和工业源,40~100 cm来源一致,主要为杀虫剂和除草剂、有机肥和化肥、自然源和交通导致的大气沉降. |
| 英文摘要 |
| In order to understand the spatial distribution, influencing factors, ecological risk characteristics, and sources of heavy metals in the soil profile （0-1 m） of farmland in the Guanzhong Plain, soil samples of 0-1 m were collected from 124 sites in the Guanzhong Plain. The contents of heavy metals （As, Cd, Cr, Cu, Ni, Pb, and Zn） in soil were analyzed at different depths （0-10 cm, 10-20 cm, 20-40 cm, 40-60 cm, and 60-100 cm）. The study generated the spatial distribution characteristics of soil heavy metals based on geostatistics and investigated the influencing factors of heavy metals based on structural equation modeling （SEM）. In addition, the ecological environmental risks of soil heavy metals were evaluated using the methods of index of geo-accumulation （Igeo）, single factor contaminant index （Pi）, and potential ecological risk index （Ei）. Finally, the sources of soil heavy metals were analyzed using the PMF model. The results showed that the average heavy metal content of ω（As）, ω（Cd）, ω（Cr）, ω（Cu）, ω（Ni）, ω（Pb）, and ω（Zn） in the 0-10 cm were 19.57, 0.71, 69.65, 21.91, 28.67, 17.54, and 73.77 mg·kg-1, respectively. The average values of As, Cd, Cr, Pb, and Zn exceeded the background values. With the increasing soil depth, all heavy metals showed a decreasing trend except for Cd and Ni. The spatial distribution indicated that different heavy metals in the same soil layer had different spatial distributions, and the spatial distribution of heavy metals also varied at different depths. The structural equation model showed that the factors affecting the distribution of heavy metals at different depths were deeply dependent. The ecological risk assessment showed that Cd at different depths had higher ecological risks, while the rest were considered minor risks. The sources of 0-40 cm soil layer were consistent, and the main sources were pesticides and herbicides, organic fertilizers and fertilizers, natural sources, and traffic-induced atmospheric subsidence and industrial sources； the sources of 40-100 cm were consistent, and the main sources were pesticides and herbicides, organic fertilizers and fertilizers, natural sources, and traffic-induced atmospheric subsidence. |
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