|
|
Banks, S. B., & Banks, D. (2001). Abandoned mines drainage; impact assessment and mitigation of discharges from coal mines in the UK. In R. N. Yong, & H. R. Thomas (Eds.), Geoenvironmental engineering Engineering Geology (pp. 31–37). 60.
Abstract: The UK has a legacy of pollution caused by discharges from abandoned coal mines, with the potential for further pollution by new discharges as groundwaters continue to rebound to their natural levels. In 1995, the Coal Authority initiated a scoping study of 30 gravity discharges from abandoned coal mines in England and Scotland. Mining information, geological information and water quality data were collated and interpreted in order to allow a preliminary assessment of the source and nature of each of the discharges. An assessment of the potential for remediation was made on the basis of the feasibility and relative costs of alternative remediation measures. Environmental impacts of the discharges and of the proposed remediation schemes were also assessed. The results, together with previous Coal Authority studies of discharges in Wales, were used by the Coal Authority, in collaboration with the former National Rivers Authority and the former Forth and Clyde River Purification Boards, to rank discharge sites in order of priority for remediation.
|
|
|
|
Boonstra, J., van Lier, R., Janssen, G., Dijkman, H., Buisman, C. J. N., & Ballester, R. A. and A. (1999). Biological treatment of acid mine drainage. In Process Metallurgy (pp. 559–567). Volume 9, Part 2: Elsevier Science B.V.
Abstract: In this paper experience obtained with THIOPAQ technology treating Acid Mine Drainage is described. THIOPAQ Technology involves biological sulfate reduction technology and the removal of heavy metals as metal sulfide precipitates. The technology was developed by the PAQUES company, who have realised over 350 high rate biological treatment plants world wide. 5 plants specially designed for sulfate reduction are successfully operated on a continuous base (1998 status). At Budelco, a zinc refinery in the Netherlands, an acid groundwater stream is effectively treated since 1992, removing metals and sulfate. At Kennecott Utah Copper (USA) a demo plant is in operation since 1995. An acid groundwater flow is treated to remove sulfate and metals, whereas the excess sulfide is used to selectively recover copper economically. Early 1998, a demonstration project was executed at the Wheal Jane mine in Cornwall, UK. In this demonstration project it has been proven that THIOPAQ technology can effectively be used to treat the Wheal Jane Acid Mine Drainage. Relative to lime dosing technology, very high removal efficiencies of all heavy metals (including cadmium and arsenic) can be obtained.
|
|
|
|
Guay, R., Cantin, P., Karam, A., Vezina, S., Paquet, A., & Ballester, R. A. and A. (1999). Effect of flooding of oxidized mine tailings on T. ferrooxidans and T. thiooxidans survival and acid mine drainage production: a 4 year restoration-environmental follow-up. In Process Metallurgy (pp. 635–643). Volume 9, Part 2: Elsevier Science B.V.
Abstract: A pilot-scale study on the effect of flooding unoxidized and oxidized Cu/Zn tailings demonstrated the technical feasability of this technology to remediate a mining site where over 3 million tons of tailings were impounded. Full-scale flooding of the tailing pond with free running water was undertaken after the construction of an impervious dam; approximately 2 million m3 of surface water at pH 7,4 completely covered the tailings after 16 months. The minimal water column over the tailings was established at 1,20 m and reached 4,5 m, depending on the site topography. Water and tailings samples were collected from 9 different locations from the surface of the man-made lake using a specially designed borer and were analyzed for pH, conductivity, iron- and sulfur-oxidizing bacteria activity and numbers as well as the sulfate reducing bacteria (SRB) population. We showed that over a four year period of flooding, the overall population of iron-oxidizers decreased considerably; their numbers drastically fell from 1x106 to 1x102 active cells per g of oxidized tailings while the SRBs increased from 101 to 105/g. The pH of the influent, the reservoir and the effluent water remained fairly constant between 6,9 up to 7,4 over the entire period. During this time, interstitial water pH increased from 2,9 to 4,3 in flooded tailings where lime could not be incorporated in the first 20 cm of tailings; elsewhere, the pH of the tailings suspensions remained fairly constant around neutral values (pH 7,0). Dissolved oxygen was measured at fixed intervals and remained also constant between 6 and 7.5 mg/L while water temperatures fluctuated below freezing point to +20C respectively in winter and summer season.
|
|
|
|
Rodiek, J., Verma, T. R., & Thames, J. L. (1975). Disturbed land rehabilitation in Lynx Creek watershed. Landscape and Planning, 2, 265–282.
Abstract: Rodiek, J., Verma, T.R. and Thames, J.L., 1976. Disturbed land rehabilitation in Lynx Creek Watershed. Landscape Plann., 2: 265-282. The Lynx Creek Watershed is located on the Prescott National Forest about 8 km south of Prescott, Arizona. The watershed, with an area of 7304 ha, has experienced intensive copper and gold mining activities in the past. Approximately 13% of the area still consists of patented mining claims (mainly copper). There are numerous abandoned mine shafts, waste dumps and mine tailings in the area. Past mining activities in the watershed have caused significant deterioration in water quality within and downstream from the mining sites. Mine drainage includes water flowing from mine shafts, surface runoff and seepage from mining dumps. Drainage from the numerous old mining sites contributes to the toxic mineral and sediment pollution of the water resources in the area. The pollutants in the form of dissolved, suspended or other solid mineral wastes and debris, enter in the streams of ground water. Aquatic life and recreation potential of the watershed is greatly reduced by the water pollution problem from the abandoned mines. The pollutants from the abandoned mines enter into Lynx Lake which is located 10 km southeast of Prescott. Lynx Lake, a trout fisheries lake, was created by a dam built in 1963 by the Arizona Game and Fish Department. The lake is 22 surface hectares in size with the storage capacity of 1.85 x 106 m3. The average yearly flow of sediment into the lake is 2900 m3. The sediment is slightly acidic and has a high concentration of copper, manganese, iron, zinc, and sulfates. The Sheldon dump and tailings pond are considered two major sources of pollution. Increasing need to direct additional attention toward mineral related problems made it necessary to coordinate U.S. Forest Service efforts with others involved in mining and reclamation. The Forest Service started SEAM (Surface Environment And Mining) in 1972 to coordinate interagency reclamation efforts. The Sheldon Mine dump and tailings pond were undertaken as a reclamation project through the coordinated efforts of the Forest Service, and the School of Renewable Natural Resources, University of Arizona at Tucson. The project is aimed at reclaiming some of the abandoned spoils in the Lynx Creek watershed and monitoring of water quality in the creek to evaluate the effectiveness of reclamation procedures. The reclamation approach includes recontouring, revegetating, drainage control and visual impact modification activities. The results to date have been encouraging. There was an excellent vegetation cover established within 5 weeks of seeding. Runoff and sediment control on the regraded slopes seemed quite effective. The methodology and technological experience gained from the reclamation project will provide invaluable information for reclaiming any abandoned mining sites within the Ponderosa Pine Ecosystem.
|
|
|
|
Kepler, D. A., & Mc Cleary, E. C. (1994). Successive Alkalinity-Producing Systems (SAPS) for the Treatment of Acid Mine Drainage. Proceedings, International Land Reclamation and Mine Drainage Conference, 1, 195–204.
Abstract: Constructed wetland treatment system effectiveness has been limited by the alkalinity-producing, or acidity-neutralizing, capabilities of systems. Anoxic limestone drains (ALD's) have allowed for the treatment of approximately 300 mg/L net acidic mine drainage, but current design guidance precludes using successive ALD's to generate alkalinity in excess of 300 mg/L because of concerns with dissolved oxygen. “Compost” wetlands designed to promote bacterially mediated sulfate reduction are suggested as a means of generating alkalinity required in excess of that produced by ALD's. Compost wetlands create two basic needs of sulfate reducing bacteria; anoxic conditions resulting from the inherent oxygen demand of the organic substrate, and quasi-circumneutral pH values resulting from the dissolution of the carbonate fraction of the compost. However, sulfate reduction treatment area needs are generally in excess of area availability and/or cost effectiveness. Second generation alkalinity-producing systems demonstrate that a combination of existing treatment mechanisms has the potential to overcome current design concerns and effectively treat acidic waters ad infinitum. Successive alkalinity-producing systems (SAPS) combine ALD technology with sulfate reduction mechanisms. SAPS promote vertical flow through rich organic wetland substrates into limestone beds beneath the organic compost, discharging the pore waters. SAPS allow for conservative wetland treatment sizing calculations to be made as a rate function based on pH and alkalinity values and associated contaminant loadings. SAPS potentially decrease treatment area requirements and have the further potential to generate alkalinity in excess of acidity regardless od acidity concentrations.
|
|
