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在上覆粘土质泥砾土的丹麦 Beder 砂质含水层中,对井域范围影响地下水中镍浓度的各种作用进行了研究。由于抽取地下水使含水层水位下降,同时随着非饱和带中黄铁矿的氧化,镍进入地下水中,浓度达4000nmol/L。经测定黄铁矿中镍的浓度为(40～140)×10~(-5)mol 镍/mol 黄铁矿。在非饱和带以及饱和带顶部的近期二次浸水段,地下水中的镍含量特别高。二次浸水带的另一个特点是 Mn~(2+)浓度上升,很明显,在黄铁矿氧化过程中,镍积累在氧化锰上。当水位再次上升时,部分氧气供给不足,黄铁矿氧化过程中释放的 Fe~(2+)没有完全氧化。活化的 Fe~(2+)可能还原氧化锰,因此将大量的 Ni~(2+)释放到地下水中。表面络合物模型计算结果表明,受重力水成分的强烈影响镍有滞后现象。相对地下水背景成分,镍滞后明显。然而,黄铁矿强氧化以及碳酸盐的溶解导致低 pH 值和高浓度 Ca~(2+)以及溶解碳酸盐的浓度产生,这些因素可以极大地使镍活化。
In the Beder sandy aquifer overlying clayey soils in Denmark, various effects on wellbore range affecting nickel concentration in groundwater were studied. Since groundwater was drained, the aquifer water level decreased. At the same time, with the oxidation of pyrite in the unsaturated zone, nickel entered the groundwater at a concentration of 4000 nmol / L. The concentration of nickel in pyrite was (40 ~ 140) × 10 ~ (-5) mol Ni / mol pyrite. The groundwater contains particularly high levels of nickel in the unsaturated zone and the second submerged section at the top of the saturation zone. Another characteristic of the secondary immersion zone is the increase of Mn 2+ concentration. It is clear that during the pyrite oxidation, nickel accumulates on the manganese oxide. When the water level rises again, part of the oxygen supply is insufficient, and the Fe 2+ released from the pyrite oxidation is not completely oxidized. Activated Fe 2+ may reduce manganese oxide, thus releasing a large amount of Ni 2+ into the groundwater. Surface complex model calculations show that there is a hysteresis of nickel due to the strong influence of gravity water composition. Relative groundwater background composition, nickel hysteresis obvious. However, the strong oxidation of pyrite and the dissolution of carbonate lead to the production of low pH and high concentration of Ca 2+ and dissolved carbonate, which can greatly activate nickel.