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Author Akcil, A.; Koldas, S.
Title Acid Mine Drainage (AMD): causes, treatment and case studies Type Journal Article
Year 2006 Publication J. Cleaner Prod. Abbreviated Journal
Volume 14 Issue 12-13 Pages 1139-1145
Keywords contamination effluents government industrial pollution industrial waste mining industry research initiatives wastewater treatment acid mine drainage environmental problems mining industry government research initiatives contamination civil engineering mining quarrying activity environmental impact acid generating process acid drainage migration prevention measures effluent treatment chemical treatment biological treatment Manufacturing and Production Entwässern=Gelände Umweltbelastung Bauingenieurwesen Bergbau Sickerwasser Steinbruch Säureproduktion Neutralisation Bergbauindustrie technische Forschung Ingenieurswissenschaft Steinbruchabbau Acid Mine Drainage Mining Environmental Chemical and biological treatment
Abstract This paper describes Acid Mine Drainage (AMD) generation and its associated technical issues. As AMD is recognized as one of the more serious environmental problems in the mining industry, its causes, prediction and treatment have become the focus of a number of research initiatives commissioned by governments, the mining industry, universities and research establishments, with additional inputs from the general public and environmental groups. In industry, contamination from AMD is associated with construction, civil engineering mining and quarrying activities. Its environmental impact, however, can be minimized at three basic levels: through primary prevention of the acid-generating process; secondary control, which involves deployment of acid drainage migration prevention measures; and tertiary control, or the collection and treatment of effluent.
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ISSN 0959-6526 ISBN Medium
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Notes Acid Mine Drainage (AMD): causes, treatment and case studies; Science Direct Approved no
Call Number CBU @ c.wolke @ 17462 Serial 36
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Author Evangelou, V.P.
Title Pyrite microencapsulation technologies: Principles and potential field application Type Journal Article
Year 2001 Publication Ecological Engineering Abbreviated Journal
Volume 17 Issue 2-3 Pages 165-178
Keywords mine water treatment Acid mine drainage Acidity Alkalinity Amelioration Coating Oxidation Surface reactions
Abstract In nature, pyrite is initially oxidized by atmospheric O2, releasing acidity and Fe2+. At pH below 3.5, Fe2+ is rapidly oxidized by T. ferrooxidans to Fe3+, which oxidizes pyrite at a much faster rate than O2. Commonly, limestone is used to prevent pyrite oxidation. This approach, however, has a short span of effectiveness because after treatment the surfaces of pyrite particles remain exposed to atmospheric O2 and oxidation continuous abiotically. Currently, a proposed mechanism for explaining non-microbial pyrite oxidation in high pH environments is the involvement of OH- in an inner-sphere electron-OH exchange between pyrite/surface-exposed disulfide and pyrite/surface-Fe(III)(OH)n3-n complex and/or formation of a weak electrostatic pyrite/surface-CO3 complex which enhances the chemical oxidation of Fe2+. The above infer that limestone application to pyritic geologic material treats only the symptoms of pyrite oxidation through acid mine drainage neutralization but accelerates non-microbial pyrite oxidation. Therefore, only a pyrite/surface coating capable of inhibiting O2 diffusion is expected to control long-term oxidation and acid drainage production. The objective of this study was to examine the feasibility in controlling pyrite oxidation by creating, on pyrite surfaces, an impermeable phosphate or silica coating that would prevent either O2 or Fe3+ from further oxidizing pyrite. The mechanism underlying this coating approach involves leaching mine waste with a coating solution composed of H2O2 or hypochlorite, KH2PO4 or H4SiO4, and sodium acetate (NaAC) or limestone. During the leaching process, H2O2 or hypochlorite oxidizes pyrite and produces Fe3+ so that iron phosphate or iron silicate precipitates as a coating on pyrite surfaces. The purpose of NaAC or limestone is to eliminate the inhibitory effect of the protons (produced during pyrite oxidation) on the precipitation of iron phosphate or silicate and to generate iron-oxide pyrite coating, which is also expected to inhibit pyrite oxidation. The results showed that iron phosphate or silicate coating could be established on pyrite by leaching it with a solution composed of: (1) H2O2 0.018-0.16 M; (2) phosphate or silicate 10-3 to 10-2 M; (3) coating-solution pH [approximate]5-6; and (4) NaAC as low as 0.01 M. Leachates from column experiments also showed that silicate coatings produced the least amount of sulfate relative to the control, limestone and phosphate treatments. On the other hand, limestone maintained the leachate near neutral pH but produced more sulfate than the control.
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ISSN 0925-8574 ISBN Medium
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Notes July 01; Pyrite microencapsulation technologies: Principles and potential field application; file:///C:/Dokumente%20und%20Einstellungen/Stefan/Eigene%20Dateien/Artikel/10063.pdf; Science Direct Approved no
Call Number CBU @ c.wolke @ 10063 Serial 37
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Author Sheoran, A.S.; Sheoran, V.
Title Heavy metal removal mechanism of acid mine drainage in wetlands: A critical review Type Journal Article
Year 2006 Publication Minerals Engineering Abbreviated Journal
Volume 19 Issue 2 Pages 105-116
Keywords Acid mine drainage Metal removal mechanism Wetlands
Abstract Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. Water infiltrating through the metal sulphide minerals, effluents of mineral processing plants and seepage from tailing dams becomes acidic and this acidic nature of the solution allows the metals to be transported in their most soluble form. The conventional treatment technologies used in the treatment of acid mine drainage are expensive both in terms of operating and capital costs. One of the methods of achieving compliance using passive treatment systems at low cost, producing treated water pollution free, and fostering a community responsibility for acid mine water treatment involves the use of wetland treatment system. These wetlands absorb and bind heavy metals and make them slowly concentrated in the sedimentary deposits to become part of the geological cycle. In this paper a critical review of the heavy metal removal mechanism involving various physical, chemical and biological processes, which govern wetland performance, have been made. This information is important for the siting and use of wetlands for remediation of heavy metals.
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Notes Heavy metal removal mechanism of acid mine drainage in wetlands: A critical review; Science Direct Approved no
Call Number CBU @ c.wolke @ 17252 Serial 41
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Author Conca, J.L.; Wright, J.
Title An Apatite II permeable reactive barrier to remediate groundwater containing Zn, Pb and Cd Type Journal Article
Year 2006 Publication Appl. Geochem. Abbreviated Journal
Volume 21 Issue 12 Pages 2188-2200
Keywords Pollution and waste management non radioactive Groundwater quality apatite groundwater remediation zinc lead cadmium acid mine drainage copper sulfate nitrate permeability water treatment precipitation chemistry
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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ISSN 0883-2927 ISBN Medium
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Notes Dec.; An Apatite II permeable reactive barrier to remediate groundwater containing Zn, Pb and Cd; Science Direct Approved no
Call Number CBU @ c.wolke @ 17248 Serial 44
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Author Heal, K.V.; Salt, C.A.
Title Treatment of acidic metal-rich drainage from reclaimed ironstone mine spoil Type Journal Article
Year 1999 Publication Water Sci. Technol. Abbreviated Journal
Volume 39 Issue 12 Pages 141-148
Keywords Acid mine drainage constructed wetland mine waste reclamation sewage sludge
Abstract Ironstone mine spoil leaves a legacy of land contamination and diffuse water pollution with acidic, metal-rich drainage. Reclamation for woodland may exacerbate water pollution due to spoil amendment and disturbance. Constructed wetland systems (CWS) are increasingly used for treating acid mine drainage but their performance is poorly understood. A combined approach was used to reclaim the Benhar ironstone spoil heap in Central Scotland. Trees have been planted in spoil treated with dried pelleted sewage sludge, limestone and peat. Spoil drainage (pH 2.7, 247 mg l-1 total Fe) passes through a CWS. Spoil throughflow, surface water chemistry and CWS performance were monitored for 12 months after reclamation. Acidity, Fe, Mn and Al concentrations declined in throughflow after reclamation, although this effect was not uniform. Soluble reactive P has been mobilised from the sewage sludge in residual areas of spoil acidity, but losses of other nutrients were short-lived. The CWS removes on average 33 % and 20-40 % of acidity and metal inputs but removal rates decrease in winter. Spoil reclamation has been successful in enabling vegetation establishment but has also increased Fe and Mn concentrations in surface drainage from the site, even after passage through the CWS.
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Notes Treatment of acidic metal-rich drainage from reclaimed ironstone mine spoil; Science Direct Approved no
Call Number CBU @ c.wolke @ 17272 Serial 45
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