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Watzlaf, G. R., Schroeder, K. T., & Kairies, C. L. (2000). Proceedings, 17th Annual National Meeting – American Society for Surface Mining and Reclamation. Tampa.
Abstract: Ten passive treatment systems, located in Pennsylvania and Maryland, have been intensively monitored for up to ten years. Influent and effluent water quality data from ten anoxic limestone drains (ALDs) and six reducing and alkalinity-producing systems (RAPS) have been analyzed to determine long-term performance for each of these specific unit operations. ALDs and RAPS are used principally to generate alkalinity, ALDs are buried beds of limestone that add alkalinity through dissolution of calcite. RAPS add alkalinity through both limestone dissolution and bacterial sulfate reduction. ALDs that received mine water containing less than 1 mg/L of both ferric iron and aluminum have continued to produce consistent concentrations of alkalinity since their construction. However, an ALD that received 20 mg/L of aluminum experienced a rapid reduction in permeability and failed within five months. Maximum levels of alkalinity (between 150 and 300 m&) appear to be reached after I5 hours of retention. All but one RAPS in this study have been constructed and put into operation only within the past 2.5 to 5 years. One system has been in operation and monitored for more than nine years. AIkalinity due to sulfate reduction was highest during the first two summers of operation. Alkalinity due to a limestone dissolution has been consistent throughout the life of the system. For the six RAPS in this study, sulfate reduction contributed an average of 28% of the total alkalinity. Rate of total alkalinity generation range from 15.6 gd''rn-'to 62.4 gd-'mL2 and were dependent on influent water quality and contact time.
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Kuyucak, N. (1998). Mining, the Environment and the Treatment of Mine Effluents. Int. J. Environ. Pollut., 10(2), 315–325.
Abstract: The environmental impact of mining on the ecosystem, including land, water and air, has become an unavoidable reality. Guidelines and regulations have been promulgated to protect the environment throughout mining activities from start-up to site decommissioning. In particular, the occurrence of acid mine drainage (AMD), due to oxidation of sulfide mineral wastes, has become the major area of concern to many mining industries during operations and after site decommissioning. AMD is characterized by high acidity and a high concentration of sulfates and dissolved metals. If it cannot be prevented or controlled, it must be treated to eliminate acidity, and reduce heavy metals and suspended solids before release to the environment. This paper discusses conventional and new methods used for the treatment of mine effluents, in particular the treatment of AMD.
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Srivastave, A., & Chhonkar, P. K. (2000). Amelioration of coal mine spoils through fly ash application as liming material. J. Ind. Res., 59(4), 309–313.
Abstract: The feasibility of fly ash as compared to lime to ameliorate the low pH of acidic coal mine spoils under controlled pot culture conditions are reported using Sudan grass (Sorghum studanens) and Oats (Avena sativa) as indicator crops. It is observed that at all levels of applications, fly ash and lime significantly increase the pH of mine spoils, available phosphorus, exchangeable potassium, available sulphur and also uptake of phosphorus, potassium, sulphur and oven-dried biomass of both these test crops. The fly ash significantly decreases the bulk density of coal mine spoils, but, there is no effect on bulk density due to lime application. However, when the spoils are amended with either fly ash or lime, the root growth occurs throughout the material. Fly ash and lime do not cause elemental toxicities to the plants as evidenced from the dry matter production by the test crops. The results indicate that fly ash to be a potential alternative to lime for treating acidic coal mine spoils.
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Eger, P., Melchert, G., Antonson, D., & Wagner, J. (1993). Magnesium hydroxide as a treatment for acid mine drainage in northern Minnesota. In B. A. Zamora, & R. E. Connolly (Eds.), Proceedings of the Annual National Meeting – American Society for Surface Mining and Reclamation, vol.10 (pp. 204–217). The challenge of integrating diverse perspectives in reclamation.
Abstract: Three alkaline materials were investigated for their suitability to treat acid mine drainage generated by a research facility located at a remote site in northern Minnesota. The materials investigated were hydrated lime, sodium hydroxide, and magnesium hydroxide. All three reagents were successful at raising pH and removing trace metals from the drainage, but the magnesium hydroxide had the added benefit of producing a maximum pH of approximately 9.5, while the other two reagents resulted in pH values of 12 and greater. In addition, the magnesium hydroxide was available as a high solid content slurry (58%) which simplified application and handling, and which produced the lowest volume of sludge of the materials tested.
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