Barton, C. D., & Karathanasis, A. D. (1997). Aerobic and anaerobic metal attenuation processes in a constructed wetland treating acid mine drainage. In AAPG Eastern Section and the Society for Organic Petrology joint meeting; abstracts (1545). 81: AAPG Bulletin.
Abstract: The use of constructed wetlands for acid mine drainage amelioration has become a popular alternative to conventional treatment methods, however, the metal attenuation processes of these systems are poorly understood. Precipitates from biotic and abiotic zones of a staged constructed wetland treating high metal load (approx. equal to 1000 mg L (super -1) ) and low pH (approx. 3.0) acid mine drainage were characterized by chemical dissolution, x-ray diffraction, thermal analysis and scanning electron microscopy. Characterization of abiotic/aerobic zones within the treatment system suggest the presence of crystalline iron oxides and hydroxides such as hematite, lepidocrocite, goethite, and jarosite. At the air/water interface of initial abiotic treatment zones, SO (sub 4) /Fe ratios were low enough (<2.0) for the formation of jarosite and goethite, but as the ratio increased due to treatment and subsequent reductions in iron concentration, jarosite was transformed to other Fe-oxyhydroxysulfates and goethite formation was inhibited. In addition, elevated pH conditions occurring in the later stages of treatment promoted the formation of amorphous iron oxyhydroxides. Biotic wetland cell substrate characterizations suggest the presence of amorphous iron minerals such as ferrihydrite and Fe(OH) (sub 3) . Apparently, high Fe (super 3+) activity, low Eh and low oxygen diffusion rates in the anaerobic subsurface environment inhibit the kinetics of crystalline iron precipitation. Some goethite, lepidocrocite and hematite, however, were observed near the surface in biotic areas and are most likely attributable to increased oxygen levels from surface aeration and/or oxygen transport by plant roots. Alkalinity generation from limestone dissolution within the substrate and bacterially mediated sulfate reduction also has a significant role on the mineral retention process. The formation of gypsum, rhodochrocite and siderite are by-products of alkalinity generating reactions in this system and may have an impact on S, Mn, and Fe solubility controls. Moreover, the buffering of acidity through excess alkalinity appears to facilitate the precipitation and retention of metals within the system.
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Bernoth, L., Firth, I., McAllister, P., & Rhodes, S. (2000). Biotechnologies for Remediation and Pollution Control in the Mining Industry. Miner. Metall. Process., 17(2), 105–111.
Abstract: As biotechnologies emerge from laboratories into main-stream application, the benefits they, offer are judged against competing technologies and business criteria. Bioremediation technologies have passed this test and are now widely used for the remediation of contaminated soils and ground waters. Bioremediation includes several distinct techniques that are used for the treatment of excavated soil and includes other techniques that are used for in situ applications. They play an important and growingrole in the mining industry for cost-effective waste management and site remediation. Most applications have been for petroleum contaminants, but advances continue to be made in the treatment of more difficult organ ic and inorganic species. This paper discusses the role of biotechnologies in remediation and pollution control from a mining-industry perspective. Several case studies are presented, including the land application of oily wastewater from maintenance workshops, the composting of hydrocarbon-contaminated soils and sludges, the bioventing of hydrocarbon solvents, the intrinsic bioremediation of diesel hydrocarbons, the biotreatment of cyanide in water front a gold mine, and the removal of manganese from acidic mine drainage.
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Boonstra, J., van Lier, R., Janssen, G., Dijkman, H., & Buisman, C. J. N. (1999). Biological treatment of acid mine drainage. In R. Amils, & A. Ballester (Eds.), Process Metallurgy, vol.9, Part B (pp. 559–567). Biohydrometallurgy and the environment toward the mining of the 21st century; proceedings of the International biohydrometallurgy symposium IBS'99, Part B, Molecular biology, biosorption, bioremediation.
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Brooks, R. P., Unz, R. F., Davis, L. K., Tarutis, W. J., & Yanchunas, J. (1990). Long-term removal and retention of iron and manganese from acidic mine drainage by wetlands.147.
Abstract: A promising low-technology solution for treating acidic mine drainage (AMD) emanating from coal mined lands involves the use of constructed wetlands.^The research was directed at addressing questions about retention mechanisms for the long-term storage of iron and manganese in constructed wetlands dominated by broad-leaved cattails (Typha latifolia).^Three sites in central Pennsylvania spanning the range of water chemistry parameters found in AMD were investigated.^When the AMD was circumneutral, and metal loadings were low, 79% of the iron, and 48% of the manganese were retained on average.^In the highly acidic site (pH approx.^= 3), < 10% of the metal loadings were retained.^The primary retention mechanism appears to be the formation of metal oxides in the aerobic zones of the sediments.^Although most microbial isolates extracted from sediment cores originated in the aerobic portions of the sediments, there was no evidence that they were transforming metals.^When AMD is circumneutral and metal loadings are low, constructed wetlands can be an effective approach to treating mine drainage.^At sites with highly acidic waters and high metal loadings, the use of constructed wetlands to treat AMD may be ineffectual, and should be implemented with caution.
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Coulton, R., Bullen, C., & Hallett, C. (2003). The design and optimisation of active mine water treatment plants. Land Contam. Reclam., 11(2), 273–280.
Abstract: This paper provides a 'state of the art' overview of active mine water treatment. The paper discusses the process and reagent selection options commonly available to the designer of an active mine water treatment plant. Comparisons are made between each of these options, based on technical and financial criteria. The various different treatment technologies available are reviewed and comparisons made between conventional precipitation (using hydroxides, sulphides and carbonates), high density sludge processes and super-saturation precipitation. The selection of reagents (quick lime, slaked lime, sodium hydroxide, sodium carbonate, magnesium hydroxide, and proprietary chemicals) is considered and a comparison made on the basis of reagent cost, ease of use, final effluent quality and sludge settling criteria. The choice of oxidising agent (air, pure oxygen, peroxide, etc.) for conversion of ferrous to ferric iron is also considered. Whole life costs comparisons (capital, operational and decommissioning) are made between conventional hydroxide precipitation and the high density sludge process, based on the actual treatment requirements for four different mine waters.
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