云南阳宗海沉积物重金属污染时空特征及潜在生态风险

发布时间：2018-07-04 07:52

本文选题：阳宗海 + 沉积物　；参考：《湖泊科学》2017年05期

【摘要】：分析了阳宗海柱状及表层沉积物中Al、Fe、Mn、Zn、Cr、Co、Ni、Cu、As、Cd、Pb等金属元素的含量,结合沉积年代学,研究了沉积物重金属污染的时空变化和潜在生态风险特征.结果表明,表层沉积物中重金属含量具有一定的空间差异性,As、Cd、Cu、Pb和Zn在中东部湖区含量较高,而Cr、Co、Ni含量高值位于南、北湖区的近岸区域;柱状沉积物中,1990s之前As、Cd、Cu、Pb和Zn含量较为稳定,1990s中后期以来,其含量逐渐增加,并在2009-2010年前后达到最大值,此后逐渐下降;而柱状沉积物中Cr、Co、Ni含量变化趋势与Al、Fe相似,总体上由下向上逐渐降低,这主要与沉积物质地(粒度)逐渐变粗有关.重金属富集系数表明,阳宗海沉积物中主要污染元素为As、Cd、Cu、Pb和Zn,1990s中后期污染程度快速增加,2009-2010年前后达到峰值,此后污染程度逐渐降低;表层沉积物中Cu为未污染至"弱"污染水平;Zn、Pb为"弱-中等"污染水平,As为"中等-强"污染水平,Cd为"弱-强"污染水平,中东部湖区污染程度高于其他湖区,这可能与该湖区缺少入湖径流、自然碎屑物质沉积速率较低以及砷污染事件等人为源的重金属贡献影响更为显著有关.生态风险评价结果表明,在2002-2010年前后沉积物重金属达到"中等-强"潜在生态危害,主要贡献因子是Cd和As,近年来其生态风险等级逐渐降低;表层沉积物中重金属在中东部湖区具有"中等"程度潜在生态危害,而其他湖区表层沉积物重金属具有较低程度的潜在生态风险.
[Abstract]:In this paper, the contents of metallic elements, such as Al _ (Fe) Fe _ (mn) _ (Zn) _ (Cr) _ (C _ (C) _ (Cu) _ (Cu _ (+) _ (1) in the columnar and surface sediments of Yangzonghai, are analyzed. Combined with sedimentary chronology, the temporal and spatial variation and potential ecological risk characteristics of heavy metal pollution in sediments The results show that there are some spatial differences in heavy metal contents in the surface sediments. The contents of Cu Pb and Zn in the central and eastern lakes are higher, while the high values of CrCoC Ni are located in the coastal areas of the northern and southern lakes. The contents of Cu Pb and Zn in the columnar sediments are relatively stable before 1990 s. The contents of Cu Pb and Zn in the columnar sediments have increased gradually since the middle and late 1990s, reached their maximum values around 2009-2010, and then decreased gradually, while the change trend of the contents of CrCoC Ni in the columnar sediments is similar to that of Alnife. As a whole, it decreases gradually from the bottom up, which is mainly related to the coarsening of sediment texture (granularity). The enrichment coefficient of heavy metals shows that the main pollution elements in the sediments of Yangzonghai are Aspergillus cassia, Cu (Pb) and Zn ~ (2 +) in the middle and late period of 1990's, and the pollution level increases rapidly and reaches its peak around 2009-2010, and then the pollution level decreases gradually. In surface sediments, Cu is not polluted to "weak" pollution level. Zn ~ (+) Pb is "weak-medium" pollution level and CD ~ (2 +) is "weak-strong" pollution level. The pollution level in the eastern and central lakes is higher than that in other lakes. This may be related to the lack of runoff into the lake, the lower deposition rate of natural clastic materials and the more significant effects of anthropogenic heavy metal contribution such as arsenic pollution events. The results of ecological risk assessment showed that the heavy metals in sediments reached "medium-strong" potential ecological hazards from 2002 to 2010, the main contributing factors were CD and As.The ecological risk grades of heavy metals gradually decreased in recent years. The heavy metals in the surface sediments have "moderate" potential ecological hazards in the middle and eastern lakes, while the heavy metals in the surface sediments of other lakes have a lower potential ecological risk.
【作者单位】：南京大学环境学院;中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室;南京信息工程大学环境科学与工程学院;云南省环境科学研究院高原湖泊流域污染过程与管理云南省重点实验室;
【基金】：科技基础性工作专项(2014FY110400) 国家自然科学基金项目(41572337,41271214) 云南省科技计划项目(2015RA084)联合资助
【分类号】：X524

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