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Baker, K. A., Fennessy, M. S., & Mitsch, W. J. (1991). Designing wetlands for controlling coal mine drainage: an ecologic- economic modelling approach. Ecological Economics, 3(1), 1–24.
Abstract: A simulation model is developed of the efficiency and economics of an application of ecotechnology – using a created wetland to receive and treat coal mine drainage. The model examines the role of loading rates of iron on treatment efficiencies and the economic costs of wetland versus conventional treatment of mine drainage. It is calibrated with data from an Ohio wetland site and verified from multi-site data from Tennessee and Alabama. The model predicts that iron removal is closely tied to loading rates and that the cost of wetland treatment is less than that of conventional for iron loading rates of approximately 20-25 g Fe m “SUP -2” day “SUP -1” and removal efficiencies less than 85%. A wetland to achieve these conditions would cost approximately US$50 000 per year according to the model. When higher loading rates exist and higher efficiencies are needed, wetland systems are more costly than conventional treatment. -Authors
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Kalin, M., Cairns, J., & McCready, R. (1991). Ecological engineering methods for acid mine drainage treatment of coal wastes. Resources, conservation and recycling, 5(2-3), 265–275.
Abstract: The treatment of acid mine drainage (AMD) through the utilization of alkali generating microbes has potential as an alternate approach to conventional lime treatment. Organic matter, a source of fixed carbon for the alkali generating microbial ecosystem, has been tested in 6 different types of AMD. The AMD characteristics range in acidities from 2 mg/l to 900 mg/l (CaCO3 equivalent), while sulphate concentrations range from 75 to 7300 mg/l. Alkali generating populations identified include iron reducers, sulphate reducers and ammonifiers. In coal AMD amended with organic matter, the microbial alkali generation is dominated by ammonifiers. Concentrations of Al, Fe and Zn in the AMD water decreased with concurrent increases in pH (3.2 to 6.5) in localized areas in the test cells.
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Burgess, J. E., & Stuetz, R. M. (2002). Activated Sludge for the Treatment of Sulphur-rich Wastewaters. Miner. Eng., 15(11), 839–846.
Abstract: The aim of this investigation was to assess the potential of activated sludge for the remediation of sulphur-rich wastewaters. A pilot-scale activated sludge plant was acclimatised to a low load of sulphide and operated as a flow-through unit. Additional sludge samples from different full-scale plants were compared with the acclimatised and unacclimatised sludges using batch absorption tests. The effects of sludge source and acclimatisation on the ability of the sludge to biodegrade high loads of sulphide were evaluated. Acclimatisation to low-sulphide concentrations enabled the sludge to degrade subsequent high loads which were toxic to unacclimatised sludge. Acclimatisation was seen to be an effect of selection pressure on the biomass, suggesting that the treatment capability of activated sludge will develop after acclimation, indicating potential for treatment of acid mine drainage (AMD) by a standard wastewater treatment process. Existing options for biological treatment of AMD are described and the potential of activated sludge treatment for AMD discussed in comparison with existing technologies. (C) 2002 Elsevier Science Ltd.
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Sheoran, A. S., & Sheoran, V. (2006). Heavy metal removal mechanism of acid mine drainage in wetlands: A critical review. Minerals Engineering, 19(2), 105–116.
Abstract: Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. Water infiltrating through the metal sulphide minerals, effluents of mineral processing plants and seepage from tailing dams becomes acidic and this acidic nature of the solution allows the metals to be transported in their most soluble form. The conventional treatment technologies used in the treatment of acid mine drainage are expensive both in terms of operating and capital costs. One of the methods of achieving compliance using passive treatment systems at low cost, producing treated water pollution free, and fostering a community responsibility for acid mine water treatment involves the use of wetland treatment system. These wetlands absorb and bind heavy metals and make them slowly concentrated in the sedimentary deposits to become part of the geological cycle. In this paper a critical review of the heavy metal removal mechanism involving various physical, chemical and biological processes, which govern wetland performance, have been made. This information is important for the siting and use of wetlands for remediation of heavy metals.
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Potgieter-Vermaak, S. S., Potgieter, J. H., Monama, P., & Van Grieken, R. (2006). Comparison of limestone, dolomite and fly ash as pre-treatment agents for acid mine drainage. Minerals Engineering, 19(5), 454–462.
Abstract: The physical, chemical and biological nature of Vaal Dam water, the main source of water in Gauteng, South Africa, is often affected by underground water pollution (acid mine water) and industrial effluents. The ecological significance and detrimental effects necessitate investigations into treating the water prior to discharge into public streams. Although several acid mine water treatment techniques and methods exist, they all have certain disadvantages. Lime treatment is the most common approach. In this investigation, limestone, dolomite and fly ash were selected as pre-treatment agents based on their low cost. Simulated acid mine water containing these agents was tested using a Jar Test apparatus. Samples were analyzed before and after treatment for pH, ferrous, ferric, calcium, magnesium and sulphate ions. The study demonstrated that the quality of the water improved with an increase in the amount and surface area of the raw material dosed and an increase in contact time. It was also influenced by the chemical composition of the acid mine water and aeration. Chemical cost savings of 38% are achieved when lime is replaced with limestone, and cost savings of 23% and 48% can be accomplished when limestone is substituted with dolomite and fly ash respectively. This could result in significant savings to the gold and coal mining industries, and could lead to a mutual benefit/gain between industrialists/polluters and the public.
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