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Conca, J. L., & Wright, J. (2006). An Apatite II permeable reactive barrier to remediate groundwater containing Zn, Pb and Cd. Appl. Geochem., 21(12), 2188–2200.
Abstract: Phosphate-induced metal stabilization involving the reactive medium Apatite II(TM) [Ca10-xNax(PO4)6-x(CO3)x(OH)2], where x < 1, was used in a subsurface permeable reactive barrier (PRB) to treat acid mine drainage in a shallow alluvial groundwater containing elevated concentrations of Zn, Pb, Cd, Cu, SO4 and NO3. The groundwater is treated in situ before it enters the East Fork of Ninemile Creek, a tributary to the Coeur d'Alene River, Idaho. Microbially mediated SO4 reduction and the subsequent precipitation of sphalerite [ZnS] is the primary mechanism occurring for immobilization of Zn and Cd. Precipitation of pyromorphite [Pb10(PO4)6(OH,Cl)2] is the most likely mechanism for immobilization of Pb. Precipitation is occurring directly on the original Apatite II. The emplaced PRB has been operating successfully since January of 2001, and has reduced the concentrations of Cd and Pb to below detection (2 μg L-1), has reduced Zn to near background in this region (about 100 μg L-1), and has reduced SO4 by between 100 and 200 mg L-1 and NO3 to below detection (50 μg L-1). The PRB, filled with 90 tonnes of Apatite II, has removed about 4550 kg of Zn, 91 kg of Pb and 45 kg of Cd, but 90% of the immobilization is occurring in the first 20% of the barrier, wherein the reactive media now contain up to 25 wt% Zn. Field observations indicate that about 30% of the Apatite II material is spent (consumed).
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Larsen, H. P. (1973). Chemical Treatment Of Metal-Bearing Mine Drainage. J. Water Poll. Control Fed., 45(8), 1682–1695.
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Mohan, D., & Chander, S. (2006). Removal and recovery of metal ions from acid mine drainage using lignite-A low cost sorbent. J. Hazard. Mater., 137(3), 1545–1553.
Abstract: Acid mine drainage (AMD), has long been a significant environmental problem resulting from the microbial oxidation of iron pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The main objective of this study was to remove and recover metal ions from acid mine drainage (AMD) by using lignite, a low cost sorbent. Lignite has been characterized and used for the AMD treatment. Sorption of ferrous, ferric, manganese, zinc and calcium in multi-component aqueous systems was investigated. Studies were performed at different pH to find optimum pH. To simulate industrial conditions for acid mine wastewater treatment, all the studies were performed using single and multi-columns setup in down flow mode. The empty bed contact time (EBCT) model was used for minimizing the sorbent usage. Recovery of the metal ions as well as regeneration of sorbent was achieved successfully using 0.1 M nitric acid without dismantling the columns. < copyright > 2006 Elsevier B.V. All rights reserved.
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Swayze, G. A. (2000). Imaging spectroscopy: A new screening tool for mapping acidic mine waste. ICARD 2000, Vols I and II, Proceedings, , 1531–+.
Abstract: Imaging spectroscopy is a relatively new remote sensing tool that provides a rapid method to screen entire mining districts for potential sources of surface acid drainage. An imaging spectrometer known as the Airborne Visible/InfraRed Imaging Spectrometer (AVIRIS) measures light reflected from the surface in 224 spectral channels from 0.4 – 2.5 mum. Spectral data from this instrument were used to evaluate mine waste at the California Gulch Superfund Site near Leadville, Colorado. Here, the process of pyrite oxidation at the surface produces acidic water that is gradually neutralized as it drains away from mine waste, depositing a central jarosite zone surrounded by a jarosite + goethite zone, in turn surrounded by a goethite zone with a discontinuous hematite rim zone. Leaching tests show that pH is most acidic in the jarosite and jarosite+goethite zones and is near-neutral in the goethite zone. Measurements indicate that metals leach from minerals and amorphous materials in the jarosite + goethite and jarosite zones at concentrations 10 – 50 times higher than from goethite zone minerals. Goethite zones that fully encircle mine waste may indicate some attenuation of leachate metals and thus reduced metal loading to streams. The potential for impact by acidic drainage is highest where streams intersect the jarosite and jarosite + goethite zones. In these areas, metal-rich acidic surface runoff may flow directly into streams. The U.S. Environmental Protection Agency estimates (U.S. EPA, 1998) that mineral maps made from AVIRIS data at Leadville have accelerated remediation efforts by two years and saved over $2 million in cleanup costs.
Keywords: mine water treatment
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Ye, Z. H. (2001). Removal and distribution of iron, manganese, cobalt, and nickel within a Pennsylvania constructed wetland treating coal combustion by-product leachate. Journal of Environmental Quality, 30(4), 1464–1473.
Abstract: A flow-through wetland treatment system was constructed to treat coal combustion by-product leachate from an electrical power station at Springdale, Pennsylvania. In a nine-compartment treatment system, four cattail (Typha latifolia L.) wetland cells (designated Cells I through 4) successfully removed iron (Fe) and manganese (Mn) from the inlet water; Fe and Mn concentrations were decreased by an average of 91% in the first year (May 1996-May 1997), and by 94 and 98% in the second year (July 1997-June 1998), respectively. Cobalt (Co) and nickel (Ni) were decreased by an average of 39 and 47% in the first year, and 98 and 63% in the second year, respectively. Most of the metal removed by the wetland cells was accumulated in sediments, which constituted the largest sink. Except for Fe, metal concentrations in the sediments tended to be greater in the top 5 em of sediment than in the 5- to 10- or 10- to 15-cm layers, and in Cell I than in Cells 2, 3, and 4. Plants constituted a much smaller sink for metals; only 0.91, 4.18, 0.19, and 0.38% of the Fe, Mn, Co, and Ni were accumulated annually in the aboveground tissues of cattail, respectively. A greater proportion of each metal (except Mn) was accumulated in cattail fallen litter and submerged Chara (a macroalga) tissues, that is, 2.81, 2.75, and 1.05% for Fe, Co, and Ni, respectively. Considerably higher concentrations of metals were associated with cattail roots than shoots, although Mn was a notable exception.
Keywords: mine water treatment
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