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Author Evangelou, V.P.
Title (up) 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 Nairn, R.W.; Griffin, B.C.; Strong, J.D.; Hatley, E.L.
Title (up) Remediation challenges and opportunities at the Tar Creek Superfund Site, Oklahoma Type Book Chapter
Year 2001 Publication Proceedings of the Annual National Meeting – American Society for Surface Mining and Reclamation, vol.18 Abbreviated Journal
Volume Issue Pages 579-584
Keywords abandoned mines acid mine drainage collapse structures constructed wetlands environmental analysis geologic hazards ground water human ecology Kansas land subsidence lead metals mines Missouri Oklahoma pollution reclamation remediation springs Superfund sites surface water Tar Creek Superfund Site United States water resources wetlands zinc 22, Environmental geology
Abstract The Tar Creek Superfund Site is a portion of the abandoned lead and zinc mining area known as the Tri-State Mining District (OK, KS and MO) and includes over 100 square kilometers of disturbed land surface and contaminated water resources in extreme northeastern Oklahoma. Underground mining from the 1890s through the 1960s degraded over 1000 surface hectares, and left nearly 50 km of tunnels, 165 million tons of processed mine waste materials (chat), 300 hectares of tailings impoundments and over 2600 open shafts and boreholes. Approximately 94 million cubic meters of contaminated water currently exist in underground voids. In 1979, metal-rich waters began to discharge into surface waters from natural springs, bore holes and mine shafts. Six communities are located within the boundaries of the Superfund site. Approximately 70% of the site is Native American owned. Subsidence and surface collapse hazards are of significant concern. The Tar Creek site was listed on the National Priorities List (NPL) in 1983 and currently receives a Hazard Ranking System score of 58.15, making Tar Creek the nation's number one NPL site. A 1993 Indian Health Service study demonstrated that 35% of children had blood lead levels above thresholds dangerous to human health. Recent remediation efforts have focused on excavation and replacement of contaminated residential areas. In January 2000, Governor Frank Keating's Tar Creek Task Force was created to take a “vital leadership role in identifying solutions and resources available to address” the myriad environmental problems. The principle final recommendation was the creation of a massive wetland and wildlife refuge to ecologically address health, safety, environmental, and aesthetic concerns. Additional interim measures included continuing the Task Force and subcommittees; study of mine drainage discharge and chat quality; construction of pilot treatment wetlands; mine shaft plugging; investigations of bioaccumulation issues; establishment of an authority to market and export chat, a local steering committee, and a GIS committee; and development of effective federal, state, tribal, and local partnerships.
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Publisher Place of Publication Editor Vincent, R.; Burger, J.A.; Marino, G.G.; Olyphant, G.A.; Wessman, S.C.; Darmody, R.G.; Richmond, T.C.; Bengson, S.A.; Nawrot, J.R.
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Notes Remediation challenges and opportunities at the Tar Creek Superfund Site, Oklahoma; GeoRef; English; 2002-036287; 18th annual national meeting of the American Society for Surface Mining and Reclamation; Land reclamation, a different approach, Albuquerque, NM, United States, June 3-7, 2001 References: 20; illus. incl. 1 table Approved no
Call Number CBU @ c.wolke @ 16526 Serial 290
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Author Ye, Z.H.
Title (up) Removal and distribution of iron, manganese, cobalt, and nickel within a Pennsylvania constructed wetland treating coal combustion by-product leachate Type Journal Article
Year 2001 Publication Journal of Environmental Quality Abbreviated Journal
Volume 30 Issue 4 Pages 1464-1473
Keywords mine water treatment
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.
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Notes Removal and distribution of iron, manganese, cobalt, and nickel within a Pennsylvania constructed wetland treating coal combustion by-product leachate; Wos:000174863000040; Times Cited: 15; ISI Web of Science Approved no
Call Number CBU @ c.wolke @ 17061 Serial 122
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Author Carlson, L.; Kumpulainen, S.
Title (up) Retention of harmful elements by ochreous precipitates of iron Type Journal Article
Year 2001 Publication Tutkimusraportti Geologian Tutkimuskeskus Abbreviated Journal
Volume - Issue 154 Pages 30-33
Keywords Surface water quality Pollution and waste management non radioactive geographical abstracts: physical geography hydrology (71 6 9) geological abstracts: environmental geology (72 14 2) iron oxide precipitation chemistry sulfate arsenate heavy metal pH water pollution remediation
Abstract The capability of soil fines to fix harmful elements, e.g. heavy metals and arsenic, depends on specific surface area and other characteristics, such as surface charge. In the pH-range typical of natural waters (pH 5,5-7,5), the surfaces of fine-grained silicate particles and manganese oxides are negatively charged; consequently cations, such as heavy metals, fix effectively to them. The iron oxide surfaces are usually positively charged and typically fix anions, such as sulphate and arsenate. Retention of anions is especially extensive to precipitates formed from acid mine drainage (pH 2,5-5,0). For example, precipitates found at Paroistenjarvi mine, Finland, contain more than 70 g/kg of arsenic (dry matter). Adsorbed anions, e.g. sulphate, enhance the capacity of precipitate to fix heavy metal cations in low-pH environments.
Address L. Carlson, Tehtaankatu 25 A 4, Helsinki FIN-00150, Finland liisa.carlson@kolumbus.fi
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ISSN 0781-4240 ISBN Medium
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Notes Retention of harmful elements by ochreous precipitates of iron; 2392974; Oksidiset rautasaostumat haitallisten aineiden pidattajina. Finland 7; Geobase Approved no
Call Number CBU @ c.wolke @ 17533 Serial 421
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Author Goulet, R.R.
Title (up) The evaluation of metal retention by a constructed wetland using the pulmonate gastropod Helisoma trivolvis (Say) Type Journal Article
Year 2001 Publication Archives of Environmental Contamination and Toxicology Abbreviated Journal
Volume 40 Issue 3 Pages 303-310
Keywords mine water treatment
Abstract Constructed wetlands are built because they can act as sinks fur many pollutants, thereby protecting the water quality of downstream ecosystems. The treatment performance is generally assessed using mass balance calculations. Along with the mass balance approach, we compared the metal content of populations of a common pond snail (Helisoma trivolvis Say) collected upstream and downstream of a 3-year-old constructed wetland. Snails were collected in early May, June, and August 1998. At the same time, water samples for particulate and dissolved metals were taken every 3 days for the duration of the experiment. Overall, the wetland retained most dissolved metals, including Fe, Mn, Cu, Zn, Ni, and Pb, but released dissolved As. However, the wetland released particulate Fe and Mn. With the exception of Zn, the metal concentrations of the downstream snails were on average higher than those measured in the upstream population. The higher metal content of downstream snails was likely related to the significant export of particulate metals by the wetland, despite the overall retention of dissolved metals. This study points to the need for biological as well as chemical monitoring to determine the treatment efficiency and toxicological risk associated with constructed wetlands.
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Notes The evaluation of metal retention by a constructed wetland using the pulmonate gastropod Helisoma trivolvis (Say); Wos:000167524900002; Times Cited: 2; ISI Web of Science Approved no
Call Number CBU @ c.wolke @ 17049 Serial 125
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