摘要: |
利用渤海湾和莱州湾近岸六个功能区(港口、养殖区、排污区、黄河口及其湿地)采集的表层沉积物, 采用BCR 连续提取法对沉积物中几种金属元素(Cu、Pb、Zn、Cr、Ni、Cd)进行了化学形态分析。形态分析结果表明, Cu、Pb、Zn、Cr、Ni 主要以残渣态存在, Cd 主要以弱酸溶态存在。基于形态分析结果应用次生相与原生相分布比值法对重金属污染水平进行评价, 结果表明, Cd 的KRSP最高, Pb 次之; 各功能区的污染水平依次为徐家铺养殖区>垦利养殖区>天津港>>大沽河排污区>黄河口及湿地>弥河排污区。同时, 对这几种金属的总含量进行了测定, 并应用Hakanson 潜在生态危害指数法对重金属元素潜在生态危害程度进行评价, 结果显示: (1)Cd 是该区域最主要的生态风险因子, 各金属的潜在生态危害程度依次为Cd>Pb>Ni≥Cu>Cr>Zn; (2)各功能区潜在生态危害程度为轻微, 功能区潜在生态危害整体上为渤海湾大于莱州湾。通过结合这两种方法进行的综合评价, 探明了这几种金属在渤海湾和莱州湾近岸功能区表层沉积物中的存在形态、迁移转化程度, 预测了其潜在生态危害。 |
关键词: 渤海功能区 表层沉积物 重金属 存在形态 连续提取法 污染评价 |
DOI:10.11693/hyhz20140900258 |
分类号: |
基金项目:国家海洋局第一海洋研究所基本科研业务专项资金项目, 2011T09 号; 海洋公益性行业专项经费资助项目, 201105003 号;国际海域资源调查与开发“十二五”规划项目, DY125-13-R-07。 |
附件 |
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GEOCHEMICAL SPECIATION AND ENVIRONMENTAL ASSESSMENT OF HEAVY METALS IN SURFACE SEDIMENTS INFUNCTIONAL ZONES OF SOUTHWEST BOHAI SEA, CHINA |
WANG Xiao-Jing, LI Li, GAO Jing-Jing, LIU Ji-Hua, ZHANG Ying
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First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
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Abstract: |
Surface sediments were collected in six functional zones (a seaport, aquaculture facilities, wastewater discharges, Huanghe(Yellow) River estuary and wetland) in Bohai and Laizhou Bays. BCR sequential extraction method was used to analyze the geochemical speciation of several metals (Cu, Pb, Zn, Cr, Ni, Cd). Results showed that, all the studied metals except for Cd were dominated in residual fraction. The acid soluble fraction was the most abundant form of Cd. The ratios of secondary phase and primary phase (KRSP) were used to assess the pollution status.The KRSP value of Cd was the highest, followed by Pb. The KRSP values of the functional zones were in the order of Xujiapu mariculture field> Kenli mariculture field>Tianjin Port>>Dagu River wastewater discharging zone>Huanghe River estuary & wetland>Mihe River wastewater discharging zone. Meanwhile, the total (bulk) metal concentrations were also analyzed, and the potential ecological risk was evaluated using the Hakanson Potential Ecological Risk Index. The results indicated that: 1) Cd had the highest potential risk, and the order of metal potential risks to the environment was Cd >Pb>Ni≥Cu>Cr>Zn; 2)The potential ecological risk of all functional zones were minor. In general, the potential ecological risk of functional zonesin Bohai Bay was greater than in Laizhou Bay. Combination of the two assessment methods has explored the speciation, mobility, and potential ecological risk of those metals in the functional zones in Bohai and Laizhou Bays. |
Key words: Bohai functional zone surface sediments heavy metal heavy metal speciation Sequential extraction method pollution evaluation |