|
Coulton, R. H., & Williams, K. P. (2005). Active treatment of mine water; a European perspective. Mine Water Env., 24(1), 23–26.
|
|
|
Ziemkiewicz, P. F., Skousen, J. G., & Simmons, J. (2003). Long-term Performance of Passive Acid Mine Drainage Treatment Systems. Mine Water Env., 22(3), 118–129.
Abstract: State and federal reclamation programs, mining operators, and citizen-based watershed organizations have constructed hundreds of passive systems in the eastern U.S. over the past 20 years to provide reliable, low cost, low maintenance mine water treatment in remote locations. While performance has been reported for individual systems, there has not been a comprehensive evaluation of the performance of each treatment type for a wide variety of conditions. We evaluated 83 systems: five types in eight states. Each system was monitored for influent and effluent flow, pH, net acidity, and metal concentrations. Performance was normalized among types by calculating acid load reductions and removals, and by converting construction cost, projected service life, and metric tonnes of acid load treated into cost per tonne of acid treated. Of the 83 systems, 82 reduced acid load. Average acid load reductions were 9.9 t/yr for open limestone channels (OLC), 10.1 t/yr for vertical flow wetlands (VFW), 11.9 t/yr for anaerobic wetlands (AnW), 16.6 t/yr for limestone leach beds (LSB), and 22.2 t/yr for anoxic limestone drains (ALD). Average costs for acid removal varied from $83/t/yr for ALDs to $527 for AnWs. Average acid removals were 25 g/m2/day for AnWs, 62 g/m2/day for VFWs, 22 g/day/t for OLCs, 28 g/day/t for LSBs, and 56 g/day/t for ALDs. It appears that the majority of passive systems are effective but there was wide variation within each system type, so improved reliability and efficiency are needed. This report is an initial step in determining passive treatment system performance; additional work is needed to refine system designs and monitoring.
|
|
|
Younger, P. L. (2000). The adoption and adaptation of passive treatment technologies for mine waters in the United Kingdom. Mine Water Env., 19(2), 84–97.
Abstract: During the 1990s, passive treatment technology was introduced to the United Kingdom (UK). Early hesitancy on the part of regulators and practitioners was rapidly overcome, at least for net-alkaline mine waters, so that passive treatment is now the technology of choice for the long-term remediation of such discharges, wherever land availability is not unduly limiting. Six types of passive systems are now being used in the UK for mine water treatment: ¨ aerobic, surface flow wetlands (reed-beds); ¨ anaerobic, compost wetlands with significant surface flow; ¨ mixed compost / limestone systems, with predominantly subsurface flow (so-called Reducing and Alkalinity Producing Systems (RAPS)); ¨ subsurface reactive barriers to treat acidic, metalliferous ground waters; ¨ closed-system limestone dissolution systems for zinc removal from alkaline waters; ¨ roughing filters for treating ferruginous mine waters where land availability is limited. Each of these technologies is appropriate for a different kind of mine water, or for specific hydraulic circumstances. The degree to which each type of system can be considered “proven technology” corresponds to the order in which they are listed above. Many of these passive systems have become foci for detailed scientific research, as part of a $1.5M European Commission project running from 2000 to 2003.
|
|
|
Simmons, J. A., Andrew, T., Arnold, A., Bee, N., Bennett, J., Grundman, M., et al. (2006). Small-Scale Chemical Changes Caused by In-stream Limestone Sand Additions to Streams. Mine Water Env., 25(4), 241–245.
Abstract: In-stream limestone sand addition (ILSA) has been employed as the final treatment for acid mine drainage discharges at Swamp Run in central West Virginia for six years. To determine the small-scale longitudinal variation in stream water and sediment chemistry and stream biota, we sampled one to three locations upstream of the ILSA site and six locations downstream. Addition of limestone sand significantly increased calcium and aluminum concentrations in sediment and increased the pH, calcium, and total suspended solids of the stream water. Increases in alkalinity were not significant. The number of benthic macroinvertebrate taxa was significantly reduced but there was no effect on periphyton biomass. Dissolved aluminum concentration in stream water was reduced, apparently by precipitation into the stream sediment.
|
|
|
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.
|
|