浙江近岸泥质区近140年来重金属元素沉积记录及其对长江流域人类活动的响应
发布时间：2018-08-24 13:58
【摘要】：对取自浙江近岸泥质区的柱状样DZ-28沉积物进行了粒度分析、210Pb和137 Cs同位素测年分析以及常量元素和重金属元素(As、Cd、Cr、Cu、Hg、Pb和Zn)含量分析,并用综合污染指数和潜在生态危害指数评价了近140年来研究区重金属污染程度的变迁。结果表明:柱状样沉积物的平均沉积速率为0.85cm/a;Al、Fe、K、Mn和Mg的含量与中值粒径具有相似的变化趋势,它们在20世纪80年代后含量逐渐增加,而Si和Ca则具有相反的变化趋势,这可能是由长江流域内大坝修建等一系列水利工程建设和上游水土保持工作的广泛开展所引起的;重金属元素含量在1982年前基本保持不变;在1982—2005年间均出现较大幅度增长,表明长江流域的人类活动强度在80年代后显著增加,导致巨量的重金属污染物被释放到长江中并被输送到研究区域,从而导致沉积物中这些元素的绝对含量明显升高;2005年后,Cu、Cr和Zn的增加趋势减缓,表明该时期内我国的环保政策等措施有效地控制了重金属污染物的排放,而Pb含量的增加可能与这一时期三峡大坝蓄水有关;研究区的重金属综合污染程度和潜在生态危害程度均低,表明近140年来研究区所面临的生态风险程度很低。近140年来重金属分布及演化特征与长江流域经济发展和国家环境保护政策等人类活动密切相关。
[Abstract]:The grain-size analysis of columnar DZ-28 sediments taken from the muddy area of Zhejiang Province was carried out. The isotopic dating of 210Pb and 137 Cs and the contents of major elements and heavy metal elements (As,Cd,Cr,Cu,Hg,Pb and Zn) were analyzed. The changes of heavy metal pollution in the study area during the past 140 years were evaluated by comprehensive pollution index and potential ecological hazard index. The results show that the average deposition rate of columnar sediments is 0.85 cm / a, and the contents of mn and Mg in Alanfen Feankek are similar to those of the median particle size. The contents of mn and Mg in columnar sediments increase gradually after 1980s, but Si and Ca have the opposite trend. This may be caused by a series of water conservancy projects such as dam construction in the Yangtze River basin and extensive development of soil and water conservation work in the upper reaches; the content of heavy metal elements remained basically unchanged before 1982; and between 1982 and 2005, there was a considerable increase in the content of heavy metals. The results show that the intensity of human activities in the Yangtze River basin increased significantly after the 1980s, resulting in the release of heavy metal pollutants into the Yangtze River and their transport to the study area. As a result, the absolute content of these elements in sediments increased obviously, and the increasing trend of Zn and Cr decreased after 2005, which indicated that the environmental protection policies and other measures effectively controlled the emission of heavy metal pollutants in this period. However, the increase of Pb content may be related to the water storage of the three Gorges Dam in this period, and the comprehensive pollution degree and potential ecological hazard degree of heavy metals in the study area are both low, which indicates that the ecological risk in the study area is very low in the last 140 years. The distribution and evolution of heavy metals in the last 140 years are closely related to human activities such as the economic development of the Yangtze River Basin and national environmental protection policies.
【作者单位】： 山东科技大学地球科学与工程学院;中国地质调查局青岛海洋地质研究所;国土资源部海洋油气资源和环境地质重点实验室;
【基金】：国家自然科学基金项目(41330964;41306063) 泰山学者工程专项经费资助 中国地质调查局地质调查项目(GZH201200506)
【分类号】：P736.21;X55
，
本文编号：2201036
[Abstract]:The grain-size analysis of columnar DZ-28 sediments taken from the muddy area of Zhejiang Province was carried out. The isotopic dating of 210Pb and 137 Cs and the contents of major elements and heavy metal elements (As,Cd,Cr,Cu,Hg,Pb and Zn) were analyzed. The changes of heavy metal pollution in the study area during the past 140 years were evaluated by comprehensive pollution index and potential ecological hazard index. The results show that the average deposition rate of columnar sediments is 0.85 cm / a, and the contents of mn and Mg in Alanfen Feankek are similar to those of the median particle size. The contents of mn and Mg in columnar sediments increase gradually after 1980s, but Si and Ca have the opposite trend. This may be caused by a series of water conservancy projects such as dam construction in the Yangtze River basin and extensive development of soil and water conservation work in the upper reaches; the content of heavy metal elements remained basically unchanged before 1982; and between 1982 and 2005, there was a considerable increase in the content of heavy metals. The results show that the intensity of human activities in the Yangtze River basin increased significantly after the 1980s, resulting in the release of heavy metal pollutants into the Yangtze River and their transport to the study area. As a result, the absolute content of these elements in sediments increased obviously, and the increasing trend of Zn and Cr decreased after 2005, which indicated that the environmental protection policies and other measures effectively controlled the emission of heavy metal pollutants in this period. However, the increase of Pb content may be related to the water storage of the three Gorges Dam in this period, and the comprehensive pollution degree and potential ecological hazard degree of heavy metals in the study area are both low, which indicates that the ecological risk in the study area is very low in the last 140 years. The distribution and evolution of heavy metals in the last 140 years are closely related to human activities such as the economic development of the Yangtze River Basin and national environmental protection policies.
【作者单位】： 山东科技大学地球科学与工程学院;中国地质调查局青岛海洋地质研究所;国土资源部海洋油气资源和环境地质重点实验室;
【基金】：国家自然科学基金项目(41330964;41306063) 泰山学者工程专项经费资助 中国地质调查局地质调查项目(GZH201200506)
【分类号】：P736.21;X55
，
本文编号：2201036
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