Groudev, S. N., Georgiev, P. S., Spasova, I. I., & Nicolova, M. N. (2000). In situ treatment of mine waters by means of a permeable barrier. Groundwater 2000, , 417–418.
Abstract: Acid ground waters contaminated with radioactive elements (U, Ra, Th), toxic heavy metals (Cu, Zn, Cd, Mn, Fe), arsenic and sulphates were treated by means of a permeable barrier. The barrier was filled with a mixture of biodegradable solid organic substrates (spent mushroom compost, sawdust and cow manure) and was inhabited by a mixed microbial community consisting of sulphate-reducing bacteria and other metabolically interdependent microorganisms. An efficient removal of the pollutants was achieved by this barrier during the different climatic seasons, even at ambient temperatures close to degrees C. The microbial dissimilatory sulphate reduction and the sorption of pollutants by the organic matter in the barrier were the main processes involved in this removal.
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Mitchell, P. (2000). Silica micro encapsulation: An innovative commercial technology for the treatment of metal and radionuclide contamination in water and soil. Environmental Issues and Management of Waste in Energy and Mineral Production, , 307–314.
Abstract: Klean Earth Environmental Company (KEECO) has developed the Silica Micro Encapsulation (SME) technology to treat heavy metals and radionuclides in water and soil. Unlike conventional neutralization/precipitation methods, SME encapsulates the contaminants in a permanent silica matrix resistant to degradation under even extreme environmental conditions. Encapsulated metals and radionuclides are effectively immobilized, minimising the potential for environmental contamination and impacts on human or ecosystem health. The effectiveness of SME has been proven through independent reviews, laboratory and field trials and commercial contracts, and the technology can be used to control and prevent acid drainage and the transport of soluble metals from mine sites, tailings areas, landfills and industrial sites. Successful demonstrations in the treatment of sediments and in brownfield redevelopment, treatment of metal-finishing wastewaters, and control of hazardous, low-level, and mixed waste at DOE/DOD sites and commercial nuclear power plants have also been undertaken. This paper describes the reactions involved in the SME process, the methods by which SME chemicals are introduced to various media, and recent project applications relevant to the cost effective remediation and prevention of environmental problems arising from energy and mineral production.
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Zaluski, M. (1999). Design and construction of bioreactors with sulfate-reducing bacteria for acid mine drainage control. Phytoremediation and Innovative Strategies for Specialized Remedial Applications, , 205–210.
Abstract: At many abandoned mine sites in the Western U.S., conventional treatment of AMD is not feasible due to the of lack of power and limited site accessibility. Therefore, three bioreactors were built at an abandoned mine site in Montana to demonstrate feasibility of treating AMD using sulphate reducing bacteria (SRB) in a passive water treatment train. The SRB are capable of increasing the pH and reducing the load of dissolved metals in the effluent. The reactors, constructed in the Fall of 1998, were designed to evaluate the SRB technology applied under different environmental conditions. Each bioreactor was designed with mechanisms to enable simulation of seasonal dry and wet climatic conditions. Two bioreactors were placed in trenches and one was constructed above the ground to investigate impact of seasonal freezing and thawing on SRB activity. Two bioreactors contain a passive pretreatment section to increase pH of water before the AMD enters the bioreactor chamber.
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Blowes, D. W., Ptacek, C. J., Benner, S. G., McRae, C. W. T., & Puls, R. W. (1998). Treatment of dissolved metals using permeable reactive barriers. Groundwater Quality: Remediation and Protection, (250), 483–490.
Abstract: Permeable reactive barriers are a promising new approach to the treatment of dissolved contaminants in aquifers. This technology has progressed rapidly from laboratory studies to full-scale implementation over the past decade. Laboratory treatability studies indicate the potential for treatment of a large number of inorganic contaminants, including As, Cd, Cr, Cu, Hg, Fe, Mn, Mo, Ni, Pb, Se, Tc, U, V, NO3, PO4, and SO4. Small scale field studies have indicated the potential for treatment of Cd, Cr, Cu, Fe, Ni, Pb, NO3, PO4, and SO4. Permeable reactive barriers have been used in full-scale installations for the treatment of hexavalent chromium, dissolved constituents associated with acid-mine drainage, including SO4, Fe, Ni, Co and Zn, and dissolved nutrients, including nitrate and phosphate. A full-scale barrier designed to prevent the release of contaminants associated with inactive mine tailings impoundment was installed at the Nickel Rim mine site in Canada in August 1995. This reactive barrier removes Fe, SO,, Ni and other metals. The effluent from the barrier is neutral in pH and contains no acid-generating potential, and dissolved metal concentrations are below regulatory guidelines. A full-scale reactive barrier was installed to treat Cr(VI) and halogenated hydrocarbons at the US Coast Guard site in Elizabeth City, North Carolina, USA in June 1996. This barrier removes Cr(VI) from >8 mg l(-1) to <0.01 mg l(-1).
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Kleinmann, R. L. P. (1998). Treatment of mine drainage by anoxic limestone drains and constructed wetlands. Acidic Mining Lakes, , 303–319.
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