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Bechard, G. (1994). Use Of Cellulosic Substrates For The Microbial Treatment Of Acid-Mine Drainage. Journal of Environmental Quality, 23(1), 111–116.
Abstract: A mixed aerobic-anaerobic microbial treatment process was developed previously for acid mine drainage (AMD) using straw as a substrate. The process was effective only if AMD was supplemented with sucrose. The present study was conducted to determine which, if any, of three cellulosic materials could sustain the microbial treatment of AMD without the addition of a sucrose amendment and to determine the effect of the retention time on the performance of the reactors. The performance of small reactors that treated simulated AMD in the continuous mode was evaluated using alfalfa (Medicago sativa L.) hay, timothy (Phleum pratense L.) hay, and straw with a 5 d retention time. Parameters measured were pH, Fe, Al, sulfate, and ammonium. Timothy hay and straw sustained AMD mitigation for 3 wk, and thereafter all activity ceased. After the reactors ceased treating AMD, the mitigative activities were reinitiated by the addition of sucrose, but not by urea. Alfalfa sustained AMD mitigation for a longer time period than either straw or timothy. The effect of three retention times, 3.5, 7, and 35 d, was then investigated for reactors containing fresh alfalfa. Increasing the retention time resulted in better metal removal and a greater pH increase. With a 7-d retention time, 75 L of simulated AMD were neutralized from a pH of 3.5 to a pH value greater than 6.5. Reactors operating with a 3.5-d retention time treated only 58.3 L of simulated AMD before failing. Ammonium was detected in effluents of active reactors. The results of this study indicate that a low maintenance microbial treatment system can be developed with alfalfa as a substrate without the addition of a sucrose amendment.
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Norris, R. H. (1987). Effectiveness Of Mine Rehabilitation In Relation To Water-Quality. Acta Biologica Hungarica, 38(1), 127–139.
Abstract: When mining is completed the sites may be completely restored to the originalecosystem, rehabilitated for some desirable environmental characteristics, desirable alternative ecosystemscreated or just neglected. The strategy adopted will depend on the intended uses of the parts of theenvironment (including water) affected by the mining. An example of rehabilitation of a metal mine nearthe Australian Federal Capital is used to illustrate the problems that may be encountered. These include:lack of controls while mining is underway; catastrophic events, such as the collapse of a settling dam,lack of site specific understanding of pyrite oxidation processes, particularly those that are biologicallyenhanced; the need for adequate biological information on which to base decisions to meet biologicalinformation on which to base decisions to meet biological objectives. Experience has shown that biologicalcollections such studies should be stored in museums where they will be valuable for comparisons of changesover long periods.
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Costigan, P. A. (1982). The reclamation of acidic colliery spoil .3. Problems associated with the use of high-rates of limestone. Journal of Applied Ecology, 19(1), 193–201.
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Barton, C. D. (1999). Renovation of a failed constructed wetland treating acid mine drainage. Environmental Geology, 39(1), 39–50.
Abstract: Acid mine drainage (AMD) from abandoned underground mines significantly impairs water quality in the Tones Branch watershed in McCreary Co., Kentucky, USA. A 1022-m(2) surface-flow wetland was constructed in 1989 to reduce the I AMD effects, however, the system failed after six months due to insufficient utilization of the treatment area, inadequate alkalinity production and metal overloading. In an attempt to improve treatment efficiencies, a renovation project was designed incorporating two anoxic limestone drains (ALDs) and a series of anaerobic subsurface drains that promote vertical now or mine water through a successive alkalinity producing system (SAPS) of limestone beds overlain by organic compost. Analytical results from the 19-month post-renovation period are very encouraging. Mean iron concentrations have decreased from 787 to 39 mg l(-1), pH increased from 3.38 to 6.46 and acidity has been reduced from 2244 to 199 mg l(-1) (CaCO3 equivalent). Mass removal rates averaged 98% for Al, 95% for Fe, 94% for acidity, 55% for sulfate and 49% for Mn during the study period. The results indicate increased alkalinity production from limestone dissolution and longer residence time have contributed to sufficient buffering and metal retention. The combination of ALDs and SAPS technologies used in the renovation and the sequence in which they were implemented within the wetland system proved to be an adequate and very promising design for the treatment of this and other sources of high metal load AMD.
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O'Sullivan, A. D., McCabe, O. M., Murray, D. A., & Otte, M. L. (1999). Wetlands for rehabilitation of metal mine wastes. Biology and Environment-Proceedings of the Royal Irish Academy, 99b(1), 11–17.
Abstract: Aspects of research work undertaken by the Wetland Ecology Research Group at University College Dublin are summarised here. Wastes from mining activities generally contain high concentrations of heavy metals and other toxic substances. Reclamation methods to treat these wastes include the use of wetlands, for revegetation of mine tailings under flooded conditions and for the treatment of tailings water. Both natural and constructed wetlands are frequently employed for the treatment of mine wastes. Through a complex array of plant, soil and microbial interactions contaminants, such as heavy metals and sulphates, can be successfully removed from wastewater. Suitable vegetation can stabilise the tailings sediment, thereby preventing it from being dust-blown or leached into the surrounding environment. Our research suggests that these two techniques for treatment of mine wastes are successful and economically viable.
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