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Title: The use of constructed wetlands to ameliorate metal-rich mine waters. Stage 1 : study of natural wetlands
Author: National Rivers Authority
Document Type: Monograph
Natural wetland areas have been observed to have an ameliorating effect on metalcontaminated mine drainage (MCMD). This study investigated the effect on water quality of four natural wetland areas in Wales which were receiving waters contaminated by metals from disused metal mines. The four areas were: the Afon Goch, which drains Parys Mountain, an abandoned copper mine on Anglesey; a wetland at the Hafha mine, Gwydir Forest, Gwynedd; a small area of wetland at Esgair Fraith, a former copper and zinc mine, and a wetland at Camdwrbach, a small abandoned lead and zinc mine. The last two sites are near the Nant y Moch reservoir in Dyfed. These four wetlands differed widely in morphology, species composition and influent MCMD composition. Fieldwork, to determine metal removal ability of these four wetlands, took place in the second quarter of 1992.Samples of water were analyzed for a range of parameters, including pH, dissolved oxygen, suspended solids, sulphate and a range of metals. Soil samples were analyzed for metals, pH and organic matter content. Some metal removal was observed, though metal removal ability varied between different wetland areas and, in some cases between sampling visits. The reasons for this variability are discussed.Natural wetlands are hydrologically complex and elucidation of the many different factors influencing metal removal may not be possible. Constructed wetlands would allow more control over the factors involved and would enable detailed investigation of the metal removal processes taking place.
Publisher: National Rivers Authority
Publication Date: Bristol
Publication Place: 1992
Subject Keywords: WetlandsEnvironmental managementMineral contentIndustrial pollutionWater qualityMine spoil
Geographic Keywords: CeredigionGwynedd
Extent: 93
Total file downloads: 285

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