Department of Applied Physics, Facultad de Ciencias Experimentales, University of Huelva, Campus de El Carmen, 21071, Huelva, Spain.
Environ Sci Pollut Res Int. 2014 Feb;21(4):2611-27. doi: 10.1007/s11356-013-2189-5. Epub 2013 Oct 6.
The Tinto and Odiel rivers in southwest Spain drain the world's largest sulfide mineral formation: the Iberian Pyrite Belt which has been worked since 2,500 BC. The Tinto and Odiel estuarine zones include both an extensive area of salt marsh and an intensively industrialized urban area. As a consequence of pyrite oxidation, the Tinto and Odiel rivers are strongly acidic (pH < 3) with unusually high and quite variable metal concentrations. In this study, seasonally varying concentrations of dissolved major and trace elements were determined in the acid mine drainage affected estuary of the Ría de Huelva. During estuarine mixing, ore-derived metal concentrations exhibit excellent correlations with pH as the main controlling parameter. As pH increases, concentrations of dissolved ore-associated elements are attenuated, and this process is enhanced during the summer months. The decrease in Fe and Al concentrations ranged from 80 to 100 % as these elements are converted from dissolved to sediment-associated forms in the estuary. Coprecipitation/adsorption processes also removed between 60 and 90 % of the originally dissolved Co, Cu, Mn, Pb, Zn, and Th; however, Cd and Ni exhibited a greater propensity to remain in solution, with an average removal of approximately 60 %. On the other hand, As and U exhibited a different behavior; it is likely that these elements remain in dissolved forms because of the formation of U carbonates and soluble As species. Concentrations of As remain at elevated levels in the outer estuary (average = 48 μg L(-1)) which exceeds concentrations present in the Tinto River. Nevertheless, the estuary has recently witnessed improvements in water quality, as compared to results of several previous studies reported in the 1990s.
西班牙西南部的廷托河和奥德耶尔河（Tinto and Odiel rivers）流经世界上最大的硫化物矿床：伊比利亚黄铁矿带（Iberian Pyrite Belt），该矿床自公元前 2500 年以来就一直在开采。廷托河和奥德耶尔河河口区包括广泛的盐沼区和高度工业化的城区。由于黄铁矿的氧化作用，廷托河和奥德耶尔河的酸性很强（pH 值<3），金属浓度异常高且变化很大。在本研究中，测定了受酸性矿山排水影响的赫乌拉湾（Ría de Huelva）河口季节变化的溶解主要和微量元素浓度。在河口混合过程中，矿石衍生金属浓度与 pH 值呈极好的相关性，pH 值是主要控制参数。随着 pH 值的升高，溶解的矿石相关元素的浓度降低，并且在夏季，这一过程得到加强。铁和铝的浓度下降了 80%至 100%，因为这些元素在河口从溶解态转化为与沉积物结合的形式。共沉淀/吸附过程还去除了原本溶解的 Co、Cu、Mn、Pb、Zn 和 Th 的 60%至 90%；然而，Cd 和 Ni 更倾向于留在溶液中，平均去除率约为 60%。另一方面，As 和 U 表现出不同的行为；这些元素可能仍以溶解形式存在，因为形成了 U 碳酸盐和可溶性 As 物种。在外河口（平均=48μg/L），As 的浓度仍保持在较高水平，超过了廷托河的浓度。然而，与 20 世纪 90 年代报告的几项先前研究相比，该河口的水质最近有所改善。
