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Matlock, M. M., Howerton, B. S., & Atwood, D. A. (2002). Chemical precipitation of heavy metals from acid mine drainage. Water Res, 36(19), 4757–4764.
Abstract: The 1,3-benzenediamidoethanethiol dianion (BDET, known commercially as MetX) has been developed to selectively and irreversibly bind soft heavy metals from aqueous solution. In the present study BDET was found to remove >90% of several toxic or problematic metals from AMD samples taken from an abandoned mine in Pikeville, Kentucky. The concentrations of metals such as iron, may be reduced at pH 4.5 from 194 ppm to below 0.009 ppm. The formation of stoichiomietric BDET-metal precipitates in this process was confirmed using X-ray powder diffraction (XRD), proton nuclear magnetic resonance (1H NMR), and infrared spectroscopy (IR).
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Demin, O. A., Dudeney, A. W. L., & Tarasova, I. I. (2002). Remediation of Ammonia-rich Minewater in Constructed Wetlands. Environ. Technol., 23(5), 497–514.
Abstract: A three-year study of ammonia removal from minewater was carried out employing constructed wetland systems (surface flow wetland and subsurface flow wetland cells) at the former Woolley Mine in West Yorkshire, UK The 1.4 Ha surface flow wetland (constructed in 1995) reduced the ammonia concentration from 3.5 – 4.5 mg l(-1) to < 2 3 mg V during the first half of the study and to essentially zero in the last year (2000 – 2001). About 25 % of contained ammonia was converted to nitrate, about 10 % was consumed by the plants and up to 30 % was converted to nitrogen gas. This maturation effect was attributed to increased depth of sludge from sedimentation of ochre, providing increased surface area for immobilisation of ammonia oxidising bacteria. The surface flow wetland finally removed 23 g m(-2) day(-1) ammonia in comparison with 3.8 g m(-2) day' for the subsurface flow (pea gravel) wetland cells, constructed for the present work and dosed with ammonium salts. Removal of ammonia by both systems was consistent with well-established mechanisms of nitrification and denitrification. It was also consistent with ammonia removal in wastewater wetland systems, although the greater aeration in the minewater systems obviated the need for special aeration cycles. The general role of wetland plants in such aerated conditions was attributed to maintaining hydraulic conditions (such as hydraulic efficiency and hydraulic resistance of substratum in subsurface flow systems) in the wetlands and providing a suspended solids filter for minewater.
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Simmons, J., Ziemkiewicz, P., & Black, D. C. (2002). Use of Steel Slag Leach Beds for the Treatment of Acid Mine Drainage. Mine Water Env., 21(2), 91–99.
Abstract: Steel slag from the Waylite steel-making plant in Bethlehem, Pennsylvania was leached with acidic mine drainage (AMD) of a known quality using an established laboratory procedure. Leaching continued for 60 cycles and leachates were collected after each cycle. Results indicated that the slag was very effective at neutralizing acidity. The AMD/slag leachates contained higher average concentrations of Ba, V, Mn, Cr, As, Ag, and Se and lower average concentrations of Sb, Fe, Zn, Be, Cd, Tl, Ni, Al, Cu, and Pb than the untreated AMD. Based on these tests, slag leach beds were constructed at the abandoned McCarty mine site in Preston County, West Virginia. The leach beds were constructed as slag check dams below limestone-lined settling basins. Acid water was captured in limestone channels and directed into basins to leach through the slag dams and discharge into a tributary of Beaver Creek. Since installation in October 2000, the system has been consistently producing net alkaline, pH 9 water. The treated water is still net alkaline and has a neutral pH after it encounters several other acidic seeps downstream.
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Chalaturnyk, R. J., Scott, J. D., & Ozum, B. (2002). Management of Oil Sands Tailings. Pet. Sci. Technol., 20(9-10), 1025–1046.
Abstract: In Alberta, oil sands bitumen is utilized for synthetic crude oil (SCO) production by surface mining, bitumen extraction followed by primary (coking) and secondary (catalytic hydro-treating) upgrading processes. SCO is further refined in specially designed or slightly modified conventional refineries into transportation fuels. Oil sands tailings, composed of water, sands, silt, clay and residual bitumen, is produced as a byproduct of the bitumen extraction process. The tailings have poor consolidation and Water release characteristics. For twenty years, significant research has been performed to improve the consolidation and water release characteristics of the tailings. Several processes were developed for the management of oil sands tailings, resulting in different recovered water characteristics, consolidation rates and consolidated solid characteristics. These processes may affect the performance of the overall plant operations. Apex Engineering Inc. (AEI) has been developing a process for, thesame purpose. In this process oil sands tailings are treated with Ca(OH)(2) lime and CO2 and thickened using a suitable thickener. The combination of chemical treatment and the use of a thickener results in the release of process water in short retention times without accumulation of any ions in the recovered water. This makes it possible to recycle the recovered water, probably after a chemical treatment, as warm as possible, which improves the thermal efficiency of the extraction process. The AEI Process can be applied in many different fashions for the management of different fractions of the tailings effluent, depending on the overall plant operating priorities.
Keywords: mine water
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Scholz, M. (2002). Mature experimental constructed wetlands treating urban water receiving high metal loads. Biotechnology Progress, 18(6), 1257–1264.
Abstract: The aim was to assess over 2 years the treatment efficiencies of vertical-flow wetland filters containing macrophytes and granular media of different. adsorption capacities. Different concentrations of lead and copper sulfate (constant for 1 year each) were added to urban beck inflow water in order to simulate pretreated (pH adjustment assumed) mine wastewater. After 1 year of operation, the inflow concentrations for lead and copper were increased from 1.30 to 2.98 and from 0.98 to 1.93 mg/L, respectively. However, the metal mass load rates (mg/m(2)/d) were increased by a factor of approximately 4.9 for lead and 4.3 for copper. No breakthrough of metals was recorded. Lead and copper accumulated in the biomass of the litter zone and rhizomes of the macrophytes. Furthermore, microbiological activity decreased during the second year of operation. Bioindicators such as ciliated protozoa and zooplankton decreased sharply in numbers but diatoms increased. In conclusion, the use of macrophytes and, adsorption media did not significantly enhance the filtration of lead and copper. Particulate lead is removed by filtration processes including straining. Furthermore, some expensive and time-consuming water quality variables can be predicted with less expensive ones such as temperature in order to reduce sampling costs.
Keywords: mine water treatment
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