Point and diffuse pollution from metal mining has led to severe environmental damage worldwide. Mine drainage is a significant problem for riverine ecosystems, it is commonly acidic (AMD), but neutral mine drainage (NMD) can also occur. A representative environment for studying metal pollution from NMD is provided by carboniferous catchments characterised by a circumneutral pH and high concentrations of carbonates, supporting the formation of secondary metal–minerals as potential sinks of metals. The present study focuses on understanding the mobility of metal pollution associated with historical mining in a carboniferous upland catchment. In the uplands of the UK, river water, sediments and spoil wastes were collected over a period of fourteen months, samples were chemically analysed to identify the main metal sources and their relationships with geological and hydrological factors. Correlation tests and principal component analysis suggest that the underlying limestone bedrock controls pH and weathering reactions. Significant metal concentrations from mining activities were measured for zinc (4.3 mg l⁻¹), and lead (0.3 mg l⁻¹), attributed to processes such as oxidation of mined ores (e.g. sphalerite, galena) or dissolution of precipitated secondary metal–minerals (e.g. cerussite, smithsonite). Zinc and lead mobility indicated strong dependence on biogeochemistry and hydrological conditions (e.g. pH and flow) at specific locations in the catchment. Annual loads of zinc and lead (2.9 and 0.2 tonnes per year) demonstrate a significant source of both metals to downstream river reaches. Metal pollution results in a large area of catchment having a depleted chemical status with likely effects on the aquatic ecology. This study provides an improved understanding of geological and hydrological processes controlling water chemistry, which is critical to assessing metal sources and mobilization, especially in neutral mine drainage areas.

中文翻译：

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了解与石炭纪高地流域的历史采矿相关的金属污染的动员

金属开采的点状和分散污染已导致全球范围内的严重环境破坏。矿山排水是河流生态系统的一个重要问题，通常是酸性的（AMD），但也可能发生中性矿山排水（NMD）。石炭流域的特点是周围环境pH值和高浓度的碳酸盐，为研究NMD造成的金属污染提供了一个典型的环境，支持形成次级金属矿物质作为潜在的金属汇。本研究的重点是了解石炭纪高地流域中与历史采矿相关的金属污染的迁移性。在英国的高地上，在十四个月的时间内收集了河水，沉积物和弃渣废物，对样品进行化学分析，以确定主要的金属来源及其与地质和水文因素的关系。相关性测试和主成分分析表明，下层的石灰岩基岩可控制pH值和风化反应。测量了采矿活动中的大量金属中锌的含量（4.3 mg l^-1）和铅（0.3 mg l ^-1），归因于诸如开采矿石的氧化（例如闪锌矿，方铅矿）或沉淀的次级金属矿物（例如铜铁矿，铁矾）的溶解。锌和铅的迁移表明对生物地球化学和水文条件的强烈依赖（例如pH和流量）在集水区的特定位置。锌和铅的年负荷量（每年分别为2.9和0.2吨）显示出下游河流中两种金属的重要来源。金属污染导致大面积集水区的化学物质枯竭，可能对水生生态产生影响。这项研究使人们对控制水化学的地质和水文过程有了更好的了解，这对于评估金属来源和动员至关重要，特别是在中性矿山排水区。