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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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Aytas, S. O., Akyil, S., Aslani, M. A. A., & Aytekin, U. (1999). Removal of uranium from aqueous solutions by diatomite (Kieselguhr). Journal of Radioanalytical and Nuclear Chemistry, 240(3), 973–976.
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Beers, W. F., Ciolkosz, E. J., & Kardos, L. T. (1974). Soil as a medium for the renovation of acid mine drainage water.
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Gong, Z., Huang, J., & Jiang, H. (1996). Study of comprehensive retrieval utilization and the treatment of acid mine wastewater. Zhongnan Gongye Daxue Xuebao = Journal of Central South University of Technology, 27(4), 432–435.
Abstract: Impact of precipitating on removing harmful metal ion in the acid mine wastewater with pH neutralizer and sulfide was studied. The possible way of retrieving heavy metal ion in wastewater was probed. The techniques for lime carbonate to reject iron for hydrogen sulfide to precipitate copper and for zinc-lime cream neutralization flocculation to treat, mine acid wastewater were chosen. The final water quality may reach national effluent standard; the copper content was 32% in the sulfide slag.
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Hill, R. D. (1974). Overview of use of carbonate rocks for controlling acid mine drainage.
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