铅污染不同粒径土壤的重金属地球化学行为与风险

发布时间：2017-12-28 17:12

本文关键词：铅污染不同粒径土壤的重金属地球化学行为与风险　出处：《中国环境科学》2017年11期 　论文类型：期刊论文

【摘要】：通过湿法提取铅污染土壤中的细砂粒、粉粒、粗粘粒和细粘粒组分,利用激光粒度分析仪、透射电镜(TEM)、X射线衍射仪(XRD)、傅里叶红外光谱(FTIR)和重金属形态连续提取的BCR方法,研究不同粒径细砂粒、粉粒、粗粘粒和细粘粒组分的重金属含量分布、矿物组成、形态分布与化学活性、迁移累积特征、生态健康风险等.结果表明,铅污染土壤中细砂粒、粉粒、粗粘粒和细粘粒组分随着颗粒物粒径的减少,总有机碳和重金属含量升高,其累积因子、活性系数和潜在生态风险指数也相对增大,特别是重金属铅的可氧化态含量显著升高.而可交换态重金属Cr、Cu、Zn则在大粒径组分中的含量较高.从综合潜在生态风险来看,铅污染土壤重金属元素在不同粒径细颗粒组分中,具有极强的潜在生态风险,在粒径特别小的纳米级天然细粘粒组分中重金属Pb和Cu具有更大的累积因子、活性系数和潜在生态风险,应采取有效措施对铅污染土壤重金属污染进行修复与治理.
[Abstract]:Lead pollution in soil fine sand, silt, coarse clay and fine clay fractions by wet extraction, using laser particle size analyzer, transmission electron microscopy (TEM), X ray diffraction (XRD), Fu Liye (FTIR) BCR infrared spectroscopy method and continuous extraction of heavy metals, the effects of particle size of sand, fine powder the distribution of heavy metal content, grain, coarse clay and fine clay fractions of the mineral composition, morphology and distribution of chemical activity, accumulation characteristics, ecological health risk. The results showed that the lead pollution in soil fine sand, silt, coarse clay and fine clay fractions with decreasing particle size, increasing the total organic carbon and the content of heavy metals, the accumulation factor, activity coefficient and potential ecological risk index is relatively increased, especially Pb increased the content of oxidizable and exchangeable heavy metals Cr, Cu and Zn in the large particle size fractions The content is high. From the view of potential ecological risk, lead pollution of soil heavy metals in different particle size of fine particle fractions, with potential ecological risk is extremely strong, in the nanometer grade natural fine clay particle size small group of heavy metals Pb and Cu have greater accumulation factor, activity coefficient and potential ecological the risk, we should take effective measures to repair and control of heavy metal pollution in soil lead pollution.
【作者单位】：陕西师范大学地理科学与旅游学院环境科学系;陕西师范大学地理学国家级实验教学示范中心;陕西师范大学中美纳米环境科学与健康国际联合研究中心;
【基金】：国家自然科学基金项目(41471420) 陕西省自然科学基础研究计划(2015JM4124) 中央高校基本科研业务费专项基金(GK201701010,GK201402032,GK200902024)
【分类号】：X142;X825
【正文快照】： 土壤天然细颗粒是指粒径小于250?m的自然土壤颗粒,包括细砂粒、粉粒、粗粘粒和细粘粒.相比于人工合成纳米颗粒(NPs)和较大尺寸人工合成颗粒(BPs)[1-3],土壤天然细颗粒组分,特别是天然土壤纳米颗粒组分,由于其粒径小、易于团聚,更易于与矿物表面相互作用包被,很难从土壤中分离

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