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Eger, P., Melchert, G., Antonson, D., & Wagner, J. (1993). Magnesium hydroxide as a treatment for acid mine drainage in northern Minnesota. In B. A. Zamora, & R. E. Connolly (Eds.), Proceedings of the Annual National Meeting – American Society for Surface Mining and Reclamation, vol.10 (pp. 204–217). The challenge of integrating diverse perspectives in reclamation.
Abstract: Three alkaline materials were investigated for their suitability to treat acid mine drainage generated by a research facility located at a remote site in northern Minnesota. The materials investigated were hydrated lime, sodium hydroxide, and magnesium hydroxide. All three reagents were successful at raising pH and removing trace metals from the drainage, but the magnesium hydroxide had the added benefit of producing a maximum pH of approximately 9.5, while the other two reagents resulted in pH values of 12 and greater. In addition, the magnesium hydroxide was available as a high solid content slurry (58%) which simplified application and handling, and which produced the lowest volume of sludge of the materials tested.
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Amacher, M. C., Brown, R. W., Kotuby-Amacher, J., & Willis, A. (1993). Adding sodium hydroxide to study metal removal in a stream affected by acid mine drainage. Research Paper, US Department of Agriculture, Forest Service, 465(17).
Abstract: Fisher Creek, a stream affected by acid mine drainage in the Beartooth Mountains of Montana, was studied to determine the extent to which copper (Cu) and zinc (Zn) would be removed from stream water when pH was increased by a pulse of sodium hydroxide (NaOH). Although the pH adjustment study indicated that precipitated Fe(OH) “SUB 3” (am) could rapidly remove Cu and Zn from a stream affected by acid mine drainage, the pH should be maintained in an optimal range (7 to 8.5) to maximize removal by adsorption. -from Authors
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Eger, P., Wagner, J. R., Kassa, J. R., & Melchert, G. D. (1994). Metal removal in wetland treatment systems. In Special Publication – United States. Bureau of Mines, Report: BUMINES-SP-06A-94 (pp. 80–88). Proceedings of the International land reclamation and mine drainage conference and Third international conference on The abatement of acidic drainage; Volume 1 of 4; Mine Drainage.
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Eger, P. (1994). Wetland Treatment for Trace-metal Removal from Mine Drainage – the Importance of Aerobic and Anaerobic Processes. Water Sci. Technol., 29(4), 249–256.
Abstract: When designing wetland treatment systems for trace metal removal, both aerobic and anaerobic processes can be incorporated into the final design. Aerobic processes such as adsorption and ion exchange can successfully treat neutral drainage in overlandflow systems. Acid drainage can be treated in anaerobic systems as a result of sulfate reduction processes which neutralize pH and precipitate metals.Test work on both aerobic and anaerobic systems has been conducted in Minnesota. For the past three years, overland flow test systems have successfully removed copper, cobalt, nickel and zinc from neutral mine drainage. Nickel, which is the major contaminant, has been reduced around 90 percent from 2 mg/L to 0.2 mg/L. A sulfate reduction system has successfully treated acid mine drainage for two years, increasing pH from 5 to over 7 and reducing concentrations of all metals by over 90 percent.Important factors to consider when designing wetlands to remove trace metals include not only the type of wetlandrequired but also the size of the system and the residence time needed to achieve the water quality standards.
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Arnekleiv, J. V., & Storset, L. (1995). Downstream effects of mine drainage on benthos and fish in a Norwegian river; a comparison of the situation before and after river rehabilitation. Heavy metal aspects of mining pollution and its remediation, 52, 35–43.
Abstract: Parts of the Norwegian river Gaula are strongly polluted from former mining activity in the area. In the most polluted parts of the river the concentration levels of Cu and Zn in 1986-1987 were up to 155 mu g l (super -1) and 186 mu g l (super -1) , respectively. In 1989 the spoil heaps in the mining area were covered with protective layers of moss-covered plastic. In 1991-1992 the concentration levels of Cu and Zn had decreased by 75% and 65%, respectively. Animal life in the polluted area seemed to be strongly affected by the trace metals in 1986-1987. The 1991-1992 results showed a marked increase in the number of species and in the number of individuals of each species of Ephemeroptera and Plecoptera, compared with the results from 1986-87. Good correlations were found between the concentrations of Cu in the water and both the number of species and the number of individuals of Ephemeroptera and Plecoptera. Analysis of the species Baetis rhodani, Diura nanseni and Rhyacophila nubila showed an average total dry weight content of Cu up to 264 mu g g (super -1) , of Zn up to 1930 mu g g (super -1) and of Cd up to 16 mu g g (super -1) . The contents of the three trace metals were significantly different from one species to another and in part between the stations for each species. In 1987 trout died after an exposure of one to two days on three test sites in the river, whereas in 1991-1992 40-75% of the trout survived an exposure period of several weeks at two of the sites. Electrofishing in 1991-1992 indicated recolonization of trout in the lower parts of the former affected and uninhabitable area.
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