The study attempted to map and predict the remobilization of metals in a floodplain which had been heavily affected by long-term Zn–Pb mining. This research, based on Zn, Cd, Pb, Ca and Fe speciation, mineralogy and the stratigraphy of sediments which had accumulated over the distance of a dozen or so km from the mine, revealed variable potential for metal mobilization. The results suggest that a drop in the water table, something to be expected after the closure of a mine, would be accompanied by a decrease in the pH of the river water and can induce the remobilization of metals associated with carbonates and exchangeable cations over the short-reach downstream of the mine. However, the mobilization of contaminants may be impeded by the alkaline, impermeable stratum of loams, which play a pivotal role in maintaining anaerobic conditions and buffering the acidity resulting from the partial degradation of sulfides. Based on the findings of the study, it can be expected that the intrinsic attenuation will limit the need for remediation works, although monitoring river water quality is recommended to determine the need for any intervention in cases where permissible quality values have been exceeded over a longer period. Results of this research can be useful as a reference for remediation works planned in other contaminated river systems experiencing water table lowering, where the mobilization of contaminants as a consequence of sediment oxidization can be expected.

中文翻译：

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受地雷影响的洪泛区的金属流动性

该研究试图绘制并预测长期受Zn-Pb开采严重影响的洪泛区中金属的迁移率。这项基于Zn，Cd，Pb，Ca和Fe的形态，矿物学和在距矿山十几公里的距离内积累的沉积物地层的研究表明，金属动员的潜力不尽相同。结果表明，地下水位下降（矿井关闭后可能会发生这种情况）将伴随河水pH值下降，并可能导致与碳酸盐和可交换阳离子相关的金属迁移。矿山下游的短距离。但是，壤土的碱性，不渗透层可能会阻碍污染物的迁移，它们在维持厌氧条件和缓冲由于硫化物的部分降解而产生的酸度中起关键作用。根据研究结果，可以预期，固有衰减将限制对修复工作的需求，尽管建议监测河流水质以确定在较长时间内超过允许质量值的情况下是否需要进行干预。期。这项研究的结果可作为在地下水位下降的其他受污染河流系统中进行的修复工作的参考依据，在这些受污染的河流系统中，由于沉积物的氧化而导致污染物的迁移有望发生。可以预期，固有衰减将限制对修复工作的需要，尽管建议监测河流水质以确定在较长时期内超过允许质量值的情况下是否需要进行任何干预。这项研究的结果可作为在地下水位降低的其他受污染河流系统中进行的修复工作的参考依据，在这些河流系统中，由于沉积物氧化而导致的污染物迁移有望发生。可以预期，固有衰减将限制对修复工作的需要，尽管建议监测河流水质以确定在较长时期内超过允许质量值的情况下是否需要进行任何干预。这项研究的结果可作为在地下水位降低的其他受污染河流系统中进行的修复工作的参考依据，在这些河流系统中，由于沉积物氧化而导致的污染物迁移有望发生。