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Fischer, R., Luckner, L., Peukert, D., Reißig, H., & Roßbach, B. (2002). Einsatz alkalischer Substanzen zur Verbesserung der Wasserqualität in Bergbaukippen. Use of alcine substances for the improvement of water quality in mining areas. Das Gas und Wasserfach. Ausgabe Wasser, Abwasser, 143(12), 891–898.
Abstract: Eisendisulfidminerale im Abraum von Braunkohlentagebauen können nach ihrer Verwitterung im wiederaufsteigenden Grundwasser erhebliche Güteverschlechterungen hinsichtlich pH-Wert, Schwermetall- und Sulfatgehalt verursachen. Diesen kann durch Zusätze alkalischer Substanzen zum Abraum wie Kalkstein, Dolomit und Kraftwerksasche bzw. Gemischen dieser Stoffe entgegengewirkt werden. Die Ergebnisse entsprechender Untersuchungen sowie die naturwissenschaftlichen Grundlagen der Eisendisulfidverwitterung werden im Beitrag dargestellt und ein Anwendungsbeispiel beschrieben. Grundlagen zur Berechnung der einzusetzenden Kalk- oder Aschemengen (bzw. Gemische der beiden Substanzen) sind die Bestimmung der oxidierbaren Sulfidminerale in den einzelnen geologischen Schichten sowie die Bestimmung der Pufferkapazität der Asche bzw. des Kalksteins. Besonders Vorteilhaft ist der Einsatz alkalischer Substanzen dort, wo durch vorhandene hohe Pyrit- und Markasitkonzentrationen mit einer erheblichen Versauerung des Grundwassers gerechnet und dadurch eine potentielle Beeinträchtigung von Grundwassernutzern erwartet werden muss. Solche Bedingungen sind im Rheinischen Braunkohlerevier, insbesondere im Umfeld des Tagebaus Garzweiler II (RWE Rheinbraun AG) gegeben. Derzeit werden im Tagebau Garzweiler bereits 40000 t Kalkstein dem Abraum beigemischt. Auch für das Lausitzer Braunkohlenrevier könnte ein Einsatz alkalischer Substanzen in Betracht gezogen werden.
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Harrington, J. M. (2002). In situ treatment of metals in mine workings and materials. Tailings and Mine Waste '02, , 251–261.
Abstract: Contact of oxygen contained in air and water with mining materials can increase the solubility of metals. In heaps leached by cyanide, metals can also be made soluble through complexation with cyanide. During closure, water in heaps, and water collected in mine workings and pit lakes may require treatment to remove these metals. In situ microbiological treatment to create reductive conditions and to precipitate metals as sulfides or elemental metal has been applied at several sites with good success. Treatment by adding organic carbon to stimulate in situ microbial reduction has been successful in removing arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel, selenium, silver, tin, uranium, and zinc to a solid phase. Closure practices can affect the success of in situ treatment at mining sites, and affect the stability of treated materials. This paper defines factors that determine the cost and permanence of in situ treatment.
Keywords: mine water treatment
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Kuyucak, N. (2002). Acid mine drainage prevention and control options. CIM Bull., 95(1060), 96–102.
Abstract: Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. It occurs as a result of natural oxidation of sulphide minerals contained in mining wastes at operating and closed/decommissioned mine sites. AMD may adversely impact the surface water and groundwater quality and land use due to its typical low pH, high acidity and elevated concentrations of metals and sulphate content. Once it develops at a mine, its control can be difficult and expensive. If generation of AMD cannot be prevented, it must be collected and treated. Treatment of AMD usually costs more than control of AMD and may be required for many years after mining activities have ceased. Therefore, application of appropriate control methods to the site at the early stage of the mining would be beneficial. Although prevention of AMD is the most desirable option, a cost-effective prevention method is not yet available. The most effective method of control is to minimize penetration of air and water through the waste pile using a cover, either wet (water) or dry (soil), which is placed over the waste pile. Despite their high cost, these covers cannot always completely stop the oxidation process and generation of AMD. Application of more than one option might be required. Early diagnosis of the problem, identification of appropriate prevention/control measures and implementation of these methods to the site would reduce the potential risk of AMD generation. AMD prevention/control measures broadly include use of covers, control of the source, migration of AMD, and treatment. This paper provides an overview of AMD prevention and control options applicable for developing, operating and decommissioned mines.
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Groudev, S. N. (2002). Treatment of acid mine drainage by a natural wetland. Wetlands and Remediation Ii, , 133–139.
Abstract: Acid drainage waters generated in the copper ore deposit Elshitza. Central Bulgaria, were treated by a natural wetland located in the deposit. The waters had a pH in the range of about 2.5 – 3.5 and contained copper, cadmium, arsenic, iron, manganese and sulphates as main pollutants. The watercourse through the wetland covered a distance of about 100 in and the water flow rate varied in the range of about 0.5 – 2.0 1/s. The wetland was characterized by an abundant water and emergent vegetation and a diverse microflora. Phragmites communis was the prevalent plant species in the wetland but species of the genera Scirpus, Typha, Juncus, Carex and Poa as well as different algae were also well present. It was found that an efficient removal of the pollutants was achieved and their residual concentrations in the wetland effluents were decreased below the relevant permissible levels for water intended for use in the agriculture and/or industry. The removal was clue to different processes but the microbial dissimilatory sulphate reduction and the sorption of pollutants by the organic matter and clay minerals present in the wetland played the main role. Negative effects of the pollutants on the growth and activity of the indigenous plant and microbial communities were not observed.
Keywords: mine water treatment
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Demin, O. A., Dudeney, A. W. L., & Tarasova, I. I. (2002). Remediation of Ammonia-rich Minewater in Constructed Wetlands. Environ. Technol., 23(5), 497–514.
Abstract: A three-year study of ammonia removal from minewater was carried out employing constructed wetland systems (surface flow wetland and subsurface flow wetland cells) at the former Woolley Mine in West Yorkshire, UK The 1.4 Ha surface flow wetland (constructed in 1995) reduced the ammonia concentration from 3.5 – 4.5 mg l(-1) to < 2 3 mg V during the first half of the study and to essentially zero in the last year (2000 – 2001). About 25 % of contained ammonia was converted to nitrate, about 10 % was consumed by the plants and up to 30 % was converted to nitrogen gas. This maturation effect was attributed to increased depth of sludge from sedimentation of ochre, providing increased surface area for immobilisation of ammonia oxidising bacteria. The surface flow wetland finally removed 23 g m(-2) day(-1) ammonia in comparison with 3.8 g m(-2) day' for the subsurface flow (pea gravel) wetland cells, constructed for the present work and dosed with ammonium salts. Removal of ammonia by both systems was consistent with well-established mechanisms of nitrification and denitrification. It was also consistent with ammonia removal in wastewater wetland systems, although the greater aeration in the minewater systems obviated the need for special aeration cycles. The general role of wetland plants in such aerated conditions was attributed to maintaining hydraulic conditions (such as hydraulic efficiency and hydraulic resistance of substratum in subsurface flow systems) in the wetlands and providing a suspended solids filter for minewater.
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