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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Anonymous. (1998). (S. H. Castro, F. Vergara, M. A. Sanchez, & D. of M. E. C. University of Concepcion, Eds.). Effluent treatment in the mining industry. Concepcion: University of Concepcion.
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Álvarez, R., Ordóñez, A., Martínez, T., Loredo, J., Pendás, F., & Younger, P. (2004). (P. Jarvis Adam, A. Dudgeon Bruce, & L. Younger Paul, Eds.). mine water 2004 – Proceedings International Mine Water Association Symposium. 2: University of Newcastle.
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Agency, U. S. E. P. (2006). Compost-free bioreactor treatment of acid rock drainage Leviathan Mine, California : innovative technology evaluation report, 2. Cincinnati, OH.: Research Laboratory, Office of Research and Development, United States Environmental Protection Agency.
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Weeks, R. E., Krohn, R., & Walker, T. H. (2000). Water management during the Pinto Valley removal action. In Tailings and Mine and Waste 2000, Proceedings of the Seventh International Conference, Fort Collins, US, Jan 22 26, 2000 (pp. 499–506).
Abstract: Der Bruch des Dammes einer Halde der Grube Nr. 14 des Kupfer- Bergbaubetriebes Pinto Valley in Arizona, USA, im Jahre 1997 führte zum Eintrag von 370000 yd(exp 3) Bergematerials und Tailings in das Bett des Flusses Pinto Creek, USA, wodurch letzteres blockiert wurde. Der Vorfall ereignete sich in bergigem Gelände unterhalb eines 14 Quadratmeilen großen Abschnittes des Flusseinzugsgebietes oberhalb des Sees Roosevelt Lake, USA, einer Trinkwasserquelle für Phoenix, USA. Aufgrund der Bedeutung des Gebietes wurde eine Strategie zur Verhütung weiterer Beeinträchtigungen der Wasserqualität ausgearbeitet. Diese beinhaltete Managementaspekte zur Gewährleistung einer schnellen Planung und Ausführung der notwendigen Arbeiten gekoppelt mit der Planung, dem Bau und dem Betrieb von Rückhalte und Umleitungssystemen für auftretende Wässer. Die Auslegung dieser Systeme erfolgte auf der Grundlage der Daten des Einzugsgebietes und der klimatischen Verhältnisse, wobei verschiedene Wahrscheinlichkeiten der Überschreitung der ermittelten Werte berücksichtigt wurden. Innerhalb von acht Monaten konnten die Tailings aus dem betroffenen Gebiet entfernt werden, ohne dass belastete Oberflächenwässer freigesetzt wurden.
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