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Tempel, R. N. (2000). A quantitative approach to optimize chemical treatment of acid drainage using geochemical reaction path modeling methods: Climax Mine, Colorado. ICARD 2000, Vols I and II, Proceedings, , 1053–1058.
Abstract: The Climax Mine, near Leadville, Colorado treats acid drainage in a lime neutralization chemical treatment system. Chemical treatment has been successful in reducing the concentration of metals to below surface water discharge effluent limits, but lime usage has not been optimized. A geochemical modeling approach has been developed to increase the efficiency of lime neutralization. The modeling approach incorporates two steps: (1)calibration, and (2) calculation of amount of lime needed to increase pH and remove metals. Results of our work quantify the lime treatment process and improve our ability to predict overall water quality.
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Sibrell, P. L. (2000). ARD remediation with limestone in a CO2 pressurized reactor. ICARD 2000, Vols I and II, Proceedings, , 1017–1026.
Abstract: We evaluated a new process for remediation of acid rock drainage (ARD). The process treats ARD with intermittently fluidized beds of granular limestone maintained within a continuous now reactor pressurized with CO2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Department of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using an ARD flow of 227 L/min. The ARD had the following characteristics: pH, 3.1; temperature, 10 OC; dissolved oxygen, 6.4 mg/L; acidity, 260 mg/L; total iron, 21 mg/L; aluminum, 22 mg/L; manganese, 7.5 mg/L; and conductivity, 1400 muS/cm. In all cases tested, processed ARD was net alkaline with mean pH and alkalinities of 6.7 and 59 mg/L at a CO2 pressure of 0 kPa, 6.6 and 158 mg/L at 34 kPa, 7.4 and 240 mg/L at 82 kPa, and 7.4 and 290 mg/L at 117 kPa. Processed ARD alkalinities were correlated to the settled bed depth (p <0.001) and CO2 pressure (p <0.001). Iron, aluminum, and manganese removal efficiencies of 96%, 99%, and 5%, respectively, were achieved with filtration following treatment. No indications of metal hydroxide precipitation or armoring of the limestone were observed. The surplus alkalinity established at 82 kPa was successful in treating an equivalent of 1136 L/min (five-fold dilution) of the combined three ARD streams entering the Toby Creek Plant. This side-stream capability provides savings in treatment unit scale as well as flexibility in treatment effect. The capability of the system to handle higher influent acidity was tested by elevating the acidity to 5000 mg/L with sulfuric acid. Net alkaline effluent was produced, indicating applicability of the process to highly acidic ARD.
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Jeffree, R. A. (2000). Rum Jungle mine site remediation: Relationship between changing water quality parameters and ecological recovery in the Finniss River system. ICARD 2000, Vols I and II, Proceedings, , 759–764.
Abstract: The Finniss River system in tropical northern Australia has received 'acid-drainage' contaminants from the Rum Jungle uranium/copper mine site over the past 4 decades. Following mine-site remediation that began in 1981-82 the annual contaminant loads of sulfate, Cu, Zn and Mn have declined by factors of 3, 7, 5 and 4, respectively over 1990-93, compared to the 1969-74 pre-remediation loads. Comparison of the frequency distributions of contaminant water concentrations over these pre- and post-remedial periods have shown varying degrees of reduction in the highest levels following mine-site remediation, that are consistent with reductions in their annual-cycle loads. Among the three selected major metal contaminants the reductions in maximum water concentrations are most pronounced for Cu. The demonstrated reductions in the highest water concentrations of all four contaminants are also associated with previously reported ecological improvement in the Finniss River system, compared to the benchmark of environmental detriment established in 1973/74, prior to the beginning of remediation at the mine site.
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Angelos, M. A. F. (2000). Rehabilitation options for a Finnish copper mine. International Conference on Practical Applications in Environmental Geotechnology Ecogeo 2000, 204, 207–214.
Abstract: The Luikonlahti Copper mine is located near the town of Kaavi in eastern Finland, approximately 30 km northwest of Outokumpu. The copper sulphide ore deposit formed the northern most part of the Outokumpu assemblage. During 15 years of operation, between 1968 and 1983, a total of 33 km of underground tunnels and 5.5 km of underground shafts were excavated in the mining of 6.85 million metric tons of ore. The underground working are now flooded with 2 million m(3) of contaminated water and three open pits contain over 1 million m(3) of contaminated water. Five separate waste rock piles exist and are actively forming acid mine drainage (AMD).
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Blowes, D. W., Ptacek, C. J., Benner, S. G., McRae, C. W. T., Bennett, T. A., & Puls, R. W. (2000). Treatment of inorganic contaminants using permeable reactive barriers. J Contam Hydrol, 45(1-2), 123–137.
Abstract: Permeable reactive barriers are an emerging alternative to traditional pump and treat systems for groundwater remediation. This technique has progressed rapidly over the past decade from laboratory bench-scale studies to full-scale implementation. Laboratory studies indicate the potential for treatment of a large number of inorganic contaminants, including As, Cd, Cr, Cu, Hg, Fe, Mn, Mo, Ni, Pb, Se, Tc, U, V, NO3, PO4 and SO4. Small-scale field studies have demonstrated treatment of Cd, Cr, Cu, Fe, Ni, Pb, NO3, PO4 and SO4. Permeable reactive barriers composed of zero-valent iron have been used in full-scale installations for the treatment of Cr, U, and Tc. Solid-phase organic carbon in the form of municipal compost has been used to remove dissolved constituents associated with acid-mine drainage, including SO4, Fe, Ni, Co and Zn. Dissolved nutrients, including NO3 and PO4, have been removed from domestic septic-system effluent and agricultural drainage.
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