Reboreda Rosa, Caçador Isabel
Institute of Oceanography, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon, Portugal.
Chemosphere. 2007 Nov;69(10):1655-61. doi: 10.1016/j.chemosphere.2007.05.034. Epub 2007 Jun 27.
Total concentrations and fractionation of Cu, Zn and Pb in seven operationally defined phases (exchangeable, carbonates, manganese oxides, organic complexes, amorphous iron oxides, crystalline iron oxides and residual) were determined in sediments colonised by the halophyte species Halimione portulacoides and Spartina maritima in a Tagus estuary salt marsh (Portugal). We aimed to determine whether the speciation of these metals was different in areas colonised by each halophyte. Higher concentrations of Cu, Zn and, in particular Pb, were found in the rhizosphere of S. maritima than in the root sediments of H. portulacoides. Geochemical fractionation of Cu, Zn and Pb in sediments of the salt marsh depended upon the metal, and for Zn and Pb clearly varied with depth and with the colonising species. The higher redox potential observed in sediments colonised by H. portulacoides may in part explain the observed differences in the speciation of Cu, Zn and Pb.
在葡萄牙塔霍河河口盐沼中，对生长有盐生植物碱蓬（Halimione portulacoides）和互花米草（Spartina maritima）的沉积物中铜、锌和铅在七个操作定义相（可交换相、碳酸盐相、锰氧化物相、有机络合物相、无定形铁氧化物相、结晶铁氧化物相和残留相）中的总浓度和分级情况进行了测定。我们旨在确定这些金属在每种盐生植物定殖区域的形态是否不同。发现互花米草根际中的铜、锌，尤其是铅的浓度高于碱蓬根际沉积物中的浓度。盐沼沉积物中铜、锌和铅的地球化学分级取决于金属，并且对于锌和铅而言，明显随深度和定殖物种而变化。在碱蓬定殖的沉积物中观察到的较高氧化还原电位可能部分解释了所观察到的铜、锌和铅形态差异。
