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Anonymous. (1998). Remediation of historical mine sites; technical summaries and bibliography. Littleton: Society for Mining, Metallurgy, and Exploration.
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Arango, I. (2002). Evaluation of the beneficial effects of the acidophilic alga Euglena mutabilis on acid mine drainage systems. Ph.D. thesis, Indiana State University,, Terre Haute.
Abstract: Euglena mutabilis is an acidophilic, photosynthetic protozoan that forms benthic mats in acid mine drainage (AMD) channels. At the Green Valley mine, western Indiana, E. mutabilis resides in AMD measuring <4.2 pH, with high concentrations of dissolved constituents (up to 22.67 g/l). One of the main factors influencing E. mutabilis distribution is water temperature. The microbe forms thick (>1 mm), extensive mats during spring and fall, when water temperature is between 13 and 28 degrees C. During winter and summer, when temperatures are outside this range, benthic communities have a very patchy distribution and are restricted to areas protected from extreme temperature changes. E. mutabilis also responds to rapid increases in pH, which are associated with rainfall events. During these events pH can increase above 4.0, causing precipitation of Fe and Al oxy-hydroxides that cover the mats. The microbe responds by moving through the precipitates, due to phototaxis, and reestablishing the community at the sediment-water interface within 12 hours. The biological activities of E. mutabilis may have a beneficial effect on AMD systems by removing iron from effluent via oxygenic photosynthesis, and/or by internal sequestration. Photosynthesis by E. mutabilis contributes elevated concentrations of dissolved oxygen (DO), up to 17.25 mg/l in the field and up to 11.83 mg/l in the laboratory, driving oxidation and precipitation of reduced metal species, especially Fe (II), which are dissolved in the effluent. In addition, preliminary electro-microscopic and staining analyses of the reddish intracellular granules in E. mutabilis indicate that the granules contain iron, suggesting that E. mutabilis sequesters iron from AMD. Inductive coupled plasma analysis of iron concentration in AMD with and without E. mutabilis also shows that E. mutabilis accelerates the rate of Fe removal from the media. Whether iron removal is accelerated by internal sequestration of iron and/or by precipitation via oxygenic photosynthesis has yet to be determined. These biological activities may play an important role in the natural remediation of AMD systems.
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Ciftci, H., & Akcil, A. (2006). Asidik maden drenajinin (AMD) giderilmesinde uygulanan biyolojik yontemler. Biological methods applied in the treatment of acid mine drainage (AMD). Madencilik = The = Journal of the Chamber of Mining Engineers of Turkey, 45(1), 35–45.
Abstract: Acidic mine drainage (AMD) is a serious environmental problem in mining areas throughout the world. AMD occurs as a result of the natural oxidation of sulfide minerals when they are exposed to oxygen and water during their disposal and storage at the mining areas. Because it includes low pH and high concentrations of dissolved metals and sulphates, AMD can potentially damage to the environment. If the formation of AMD can't be prevented and controlled, it must be collected and treated to remove acidity and reduce the concentration of heavy metals and suspended solids before its release to the environment. Different types of microorganisms in the treatment of AMD can play a very important role in the development and the application of microbiological prevention, control and treatment technologies. The purpose of this article is to give information about the passive biological methods used in the treatment and the control of AMD and the role of microorganisms in these methods.
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Faulkner, B. B., Skousen, J. G., Skousen, J. G., & Ziemkiewicz, P. F. (1996). Treatment of acid mine drainage by passive treatment systems. In Acid mine drainage control and treatment. Morgantown: West Virginia University and the National Mine Land Reclamation Center.
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Fisher, T. S. R., & Lawrence, G. A. (2006). Treatment of acid rock drainage in a meromictic mine pit lake. Journal of environmental engineering, 132(4), 515–526.
Abstract: The Island Copper Mine pit near Port Hardy, Vancouver Island, B.C., Canada, was flooded in 1996 with seawater and capped with fresh water to form a meromictic (permanently stratified) pit lake of maximum depth 350 m and surface area 1.72 km2. The pit lake is being developed as a treatment system for acid rock drainage. The physical structure and water quality has developed into three distinct layers: a brackish and well-mixed upper layer; a plume stirred intermediate layer; and a thermally convecting lower layer. Concentrations of dissolved metals have been maintained well below permit limits by fertilization of the surface waters. The initial mine closure plan proposed removal of heavy metals by metal-sulfide precipitation via anaerobic sulfate-reducing bacteria, once anoxic conditions were established in the intermediate and lower layers. Anoxia has been achieved in the lower layer, but oxygen consumption rates have been less than initially predicted, and anoxia has yet to be achieved in the intermediate layer. If anoxia can be permanently established in the intermediate layer then biogeochemical removal rates may be high enough that fertilization may no longer be necessary. < copyright > 2006 ASCE.
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