THE GEOCHEMICAL CYCLING OF TRACE-ELEMENTS IN A BIOGENIC MEROMICTIC LAKE
THE GEOCHEMICAL CYCLING OF TRACE-ELEMENTS IN A BIOGENIC MEROMICTIC LAKE
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DOI：
10.1016/0016-7037(94)90262-3
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发表时间：
1994-10-01
影响因子：
5
通讯作者：
PAUL, B
中科院分区：
文献类型：
--
作者：
BALISTRIERI, LS;MURRAY, JW;PAUL, B
通过考察溶解态和酸溶态元素的颗粒剖面，并利用热力学计算结果，对影响美国华盛顿霍尔湖As、Co、Cr、Cu、Fe、Mn、Mo、Ni、Pb、V和Zn的行为和形态的地球化学过程进行了评价。这个不完全混合湖的水柱是高度分层的，包含独特的好氧层、亚氧层和缺氧层。水柱的氧化还原状态随深度的变化会影响所研究的所有元素的分布。最明显的是溶解的Co，Cr，Fe，Mn，Ni，Pb和Zn浓度在氧化-亚氧化边界上增加，溶解的As，Co，Cr，Fe，Mn和V浓度在缺氧层中随深度增加，溶解的Cu，Ni，Pb和Zn浓度在低于硫化物最大值的缺氧区域中显著降低，以及As，Cr，铜、铁、钼、镍、铅、钒和锌在硫化物最大值以下的缺氧区。缺氧区的热力学计算表明，所有的氧化还原敏感性元素存在于其还原形式，主要溶解形式的Cu，Ni，Pb，和Zn的金属硫化物溶液络合物，和固体硫化物相的Cu，Fe，Mo，和Pb过饱和。使用垂直扩散和反应模型的计算表明，霍尔湖中Mn（II）的氧化速率常数估计为0.006 d（-1），处于其他自然系统中观察到的微生物氧化速率范围的低端。影响霍尔湖微量元素分布和形态的主要地球化学过程是溶解态元素在氧化态之间的转化（As，Cr，Cu，Fe，Mn，V），微量元素与Mn和Fe的共循环（As，Co，Cr，Cu，Mo，Ni，Pb，V，Zn），形成可溶性金属硫化物络合物（Co、Cu、Ni、Pb、Zn）、吸附（As、Co、Cr、Ni、V）和沉淀（Cu、Fe、Mn、Mo、Pb、Zn）。
The geochemical processes affecting the behavior and speciation of As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn in Hall Lake, Washington, USA, are assessed by examining dissolved and acid soluble particulate profiles of the elements and utilizing results from thermodynamic calculations. The water column of this meromictic lake is highly stratified and contains distinctive oxic, suboxic, and anoxic layers. Changes in the redox state of the water column with depth affect the distribution of all the elements studied. Most noticeable are increases in dissolved Co, Cr, Fe, Mn, Ni, Pb, and Zn concentrations across the oxic-suboxic boundary, increases in dissolved As, Co, Cr, Fe, Mn, and V concentrations with depth in the anoxic layer, significant decreases in dissolved Cu, Ni, Pb, and Zn concentrations in the anoxic region below the sulfide maximum, and large increases in acid soluble particulate concentrations of As, Cr, Cu, Fe, Mo, Ni, Pb, V, and Zn in the anoxic zone below the sulfide maximum. Thermodynamic calculations for the anoxic region indicate that all redox sensitive elements exist in their reduced forms, the primary dissolved forms of Cu, Ni, Pb, and Zn are metal sulfide solution complexes, and solid sulfide phases of Cu, Fe, Mo, and Pb are supersaturated. Calculations using a vertical diffusion and reaction model indicate that the oxidation rate constant for Mn(II) in Hall Lake is estimated to be 0.006 d(-1) and is at the lower end of the range of microbial oxidation rates observed in other natural systems. The main geochemical processes influencing the distribution and speciation of trace elements in Hall Lake appear to be transformations of dissolved elements between their oxidation states (As, Cr, Cu, Fe, Mn, V), cocycling of trace elements with Mn and Fe (As, Co, Cr, Cu, Mo, Ni, Pb, V, Zn), formation of soluble metal sulfide complexes (Co, Cu, Ni, Pb, Zn), sorption (As, Co, Cr, Ni, V), and precipitation (Cu, Fe, Mn, Mo, Pb, Zn).