沣河沿岸土壤和优势植物重金属富集特征和潜在生态风险

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 沣河沿岸土壤和优势植物重金属富集特征和潜在生态风险 DOI: 10.5846/stxb201206150859 作者: 作者单位: 陕西师范大学旅游与环境学院,陕西师范大学,陕西师范大学旅游与环境学院,陕西师范大学物理学与信息技术学院,陕西师范大学数学与信息科学学院,陕西师范大学旅游与环境学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家水体污染控制与治理科技重大专项渭河典型重污染支流综合整治技术集成与示范子课题（2008ZX07012-002-004）；国家级大学生创新项目（1110718025） Enrichment and ecological risk of heavy metal in soils and dominant plants in the riparian of the Fenghe River Author: Affiliation: College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi,College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi,College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi,College of Physics and Information Technology,Shaanxi Normal University,Xi’an Shaanxi,College of Mathematics and Information Science,Shaanxi Normal University,Xi’an Shaanxi,College of Tourism and Environment,Shaanxi Normal University,Xi’an Shaanxi Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:测定陕西省沣河沿岸32个土壤样品和16个优势植物样品中Cr、Cu、Mn、Pb、Zn和Ni 6种重金属元素的含量，并结合数据统计与GIS制图，对土壤和植物中重金属的空间分布、富集特征及潜在风险进行分析。结果表明沣河中下游沿岸土壤和植物中Cr、Mn、Pb、Zn和Ni含量空间分布呈明显富集。土壤中Cr、Mn和Pb的几何均值分别为92.1、611.1和32.9 mg/kg，均高于陕西省土壤元素背景值；植物中Mn、Zn含量在正常范围内，Cr、Cu、Ni含量部分超标，Pb含量整体较高，地上部分对Pb的积累量达到15.5 mg/kg，约为正常情况下的7.8倍。马齿苋、艾蒿、芦苇和水蓼4种植物生物量大，对这六种重金属富集能力均较强，可作为该地区耐重金属植物。沣河沿岸土壤和植物中重金属污染值得关注。 Abstract:Heavy metal contamination in rivers has become a major issues in recent decades due to their biogeochemical cycling, environmental persistence, and ecological risks. Intensive attention has been given to river sediment contamination but heavy metals in soils and plants along the river ecosystem have been inadequately studied. The results of this research will contribute to a better understanding of heavy metal characteristics, pollution status assessment, affect in river ecosystems, and environmental protection of rivers. A total of 32 soils and 16 dominant plants samples were collected in the riparian of the Fenghe river of Shaanxi Province from the headwater to the river mouth. The spatial distribution, accumulation characteristics, and potential risk of heavy metals in the soils and plants were investigated by measuring total concentrations of Cr, Cu, Mn, Pb, Zn, and Ni in soils and plants via X-Ray fluorescence spectrometry and atomic absorption spectroscopy, GIS mapping, and by analyzing the relationship between heavy metal concentrations in soils and plants. Significant spatial accumulation of Cr, Mn, Pb, Zn, and Ni in soils and plants were found midstream and downstream. The geometrical mean concentrations of Cr, Mn, and Pb in soils were 92.1, 611.1, and 32.9 mg/kg, respectively. The average concentrations of Cr, Mn, and Pb exceeded the corresponding background values of Shaanxi topsoil while the average concentrations of Zn, Cu, and Ni were lower. Taking the China Environmental Quality Standard (GB15618-1995, GradeⅠ) for soils as a reference, the ratio of all the samples in soils above the limit were 75% for Cr, 19% for Cu, 63% for Mn, 25% for Pb, and 6% for Ni, which indicates the pollution characteristics of multi-metals in soils are mainly due to Cr. The Nemero Index showed that the soils in the riparian of the Fenghe River were moderately polluted. The Geo-accumulation Index showed that soils were not polluted with Mn and Zn but there was mild Pb, Ni, Cr, and Cu contamination in some samples. The heavy metal concentrations in plants in the riparian of the Fenghe River had normal distribution. The Cr, Cu, and Ni concentrations of Pb in some samples were above critical values, while the Pb concentrations were high in all samples. The geometrical mean concentrations of Pb in the above-ground biomass, which accumulated to 15.5 mg/kg, was 7-8 times the normal concentrations in plants. This paper did not screen out new plants which satisfied with the standard of hyperaccumulators, but Portulaca oleracea., Artemisia argyi, Phragmites communis, and Polygonum hydropiper grew well and were potentially tolerant species. There were significant positive correlations among the concentrations of Cr, Cu, Zn, Mn, Ni, and Pb in the soils and plants, and the Cr concentrations in soils promoted the accumulation of Ni in the underground biomass. Along with Pb increase in the soil was a corresponding increase in Zn, Mn, and Pb in plant roots. It is necessary to focus on the potential risk of heavy metals for water safety and human health in soils and plants in the riparian of the Fenghe River. 参考文献 相似文献 引证文献