Ye, Z. H., Whiting, S. N., Qian, J. H., Lytle, C. M., Lin, Z. Q., & Terry, N. (2001). Trace element removal from coal ash leachate by a 10-year-old constructed wetland. J. Environ. Qual., 30(5), 1710–1719.
Abstract: This study investigated the ability of a 10-yr-old constructed wetland to treat metal-contaminated leachate emanating from a coal ash pile at the Widows Creek electric utility, Alabama (USA). The two vegetated cells, which were dominated by cattail (Typha latifolia L.) and soft rush (Juncus effusus L.), were very effective at removing Fe and Cd from the wastewater, but less efficient for Zn, S, B, and Mn. The concentrations were decreased by up to 99% for Fe, 91% for Cd, 63% for Zn, 61% for S, 58% for Mn, and 50% for B. Higher pH levels (>6) in standing water substantially improved the removing efficiency of the wetland for Mn only. The belowground tissues of both cattail and soft rush had high concentrations of all elements; only for Mn, however, did the concentration in the shoots exceed those in the belowground tissues. The concentrations of trace elements in fallen litter were higher than in the living shoots, but lower than in the belowground tissues. ne trace element accumulation in the plants accounted for less than 2.5% of the annual loading of each trace element into the wetland. The sediments were the primary sinks for the elements removed from the wastewater. Except for Mn, the concentrations of trace elements in the upper layer (0-5 cm) of the sediment profile tended to be higher than the lower layers (5-10 and 10-15 cm). We conclude that constructed wetlands are still able to efficiently remove metals in the long term (i.e., >10 yr after construction).
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Schueck, J. H. (1995). Limestone diversion wells; a low-maintenance, cost-effective method for treating acid-mine drainage with limestone. In C. R. Carnein, & J. H. Way (Eds.), Guidebook for the Annual Field Conference of Pennsylvania Geologists, vol.60 Applied geology in the Lock Haven and Williamsport region, Clinton and Lycoming counties, northcentral Pennsylvania (pp. 9–12).
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Karathanasis, A. D., & Barton, C. D. (1999). The revival of a failed constructed wetland treating a high Fe load AMD. In K. S. Sajwan, A. K. Alva, & R. F. Keefer (Eds.), Proceedings; biogeochemistry of trace elements in coal and coal combustion byproducts. New York: Kluwer Academic/Plenum Publishers.
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Younger, P. L. (2000). Holistic remedial strategies for short- and long-term water pollution from abandoned mines. Transactions of the Institution of Mining and Metallurgy Section a-Mining Technology, 109, A210–A218.
Abstract: Where mining proceeds below the water-table-as it has extensively in Britain and elsewhere-water ingress is not only a hindrance during mineral extraction but also a potential liability after abandonment. This is because the cessation of dewatering that commonly follows mine closure leads to a rise in the water-table and associated, often rapid, changes in the chemical regime of the subsurface. Studies over the past two decades have provided insights into the nature and time-scales of these changes and provide a basis for rational planning of mine-water management during and after mine abandonment. The same insights into mine-water chemistry provide hints for the efficient remediation of pollution (typically due to Fe, Mn and Al and, in some cases, Zn, Cd, Pb and other metals). Intensive treatment (by chemical dosing with enhanced sedimentation or alternative processes, such as sulphidization or reverse osmosis) is often necessary only during the first few years following complete flooding of mine voids. Passive treatment (by the use of gravity-flow geochemical reactors and wetlands) may be both more cost-effective and ecologically more responsible in the long term. By the end of 1999 a total of 28 passive systems had been installed at United Kingdom mine sites, including examples of system types currently unique to the United Kingdom. Early performance data for all the systems are summarized and shown to demonstrate the efficacy of passive treatment when appropriately applied.
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Stewart, D., Norman, T., Cordery-Cotter, S., Kleiner, R., Sweeney, E., & Nelson, J. D. (1997). Utilization of a ceramic membrane for acid mine drainage treatment. Tailings and Mine Waste '97, , 453–460.
Abstract: BASX Systems LLC has developed a treatment system based on ceramic membranes for the removal of heavy metals from an acid mine drainage stream. This stream also contained volatile organic compounds that were required to be removed prior to discharge to a Colorado mountain stream. The removal of heavy metals was greater than 99% in most cases. A decrease of 30% in chemicals required for treatment and a reduction by more than 75% in labor over a competing technology were achieved. These decreases were obtained for operating temperatures of less than 5 degrees C. This system of ceramic microfiltration is capable of treating many different types of acid mine waste streams for heavy metals removal.
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