|   | 
Details
   web
Records
Author (up) Demchak, J.; Morrow, T.; Skousen, J.; Donovan, J.J.; Rose, A.W.
Title Treatment of acid mine drainage by four vertical flow wetlands in Pennsylvania Evolution and remediation of acid-sulfate groundwater systems at reclaimed mine-sites Type Journal Article
Year 2001 Publication Geochemistry – Exploration, Environment, Analysis Abbreviated Journal
Volume 1 Issue 1 Pages 71-80
Keywords acid mine drainage alkalinity anaerobic environment Appalachian Plateau Appalachians carbonate rocks Clearfield County Pennsylvania constructed wetlands Eh equilibrium Filson Wetlands ground water Howe Bridge Wetlands hydrology Jefferson County Pennsylvania limestone McKinley Wetlands Mill Creek watershed Moose Creek movement North America passive methods Pennsylvania pH pollution reclamation sedimentary rocks Sommerville Wetlands systems United States water treatment watersheds wetlands 22 Environmental geology 02B Hydrochemistry
Abstract Acid mine drainage (AMD) is a serious problem in many watersheds where coal is mined. Passive treatments, such as wetlands and anoxic limestone drains (ALDs), have been developed, but these technologies show varying treatment efficiencies. A new passive treatment technique is a vertical flow wetland or successive alkalinity producing system (SAPS). Four SAPS in Pennsylvania were studied to determine changes in water chemistry from inflow to outflow. The Howe Bridge SAPS removed about 130 mg l (super -1) (40%) of the inflow acidity concentration and about 100 mg l (super -1) (60%) iron (Fe). The Filson 1 SAPS removed 68 mg l (super -1) (26%) acidity, 20 mg l (super -1) (83%) Fe and 6 mg l (super -1) (35%) aluminium (Al). The Sommerville SAPS removed 112 mg l (super -1) (31%) acidity, exported Fe, and removed 13 mg l (super -1) (30%) Al. The McKinley SAPS removed 54 mg l (super -1) (91%) acidity and 5 mg l (super -1) (90%) Fe. Acid removal rates at our four sites were 17 (HB), 52 (Filson1), 18 (Sommerville) and 11 (McKinley) g of acid per m (super 2) of surface wetland area per day (g/m (super 2) d (super -1) ). Calcium (Ca) concentrations in the SAPS effluents were increased between 8 and 57 mg l (super -1) at these sites. Equilibrators, which were inserted into compost layers to evaluate redox conditions at our sites, showed that reducing conditions were generally found at 60 cm compost depths and oxidized conditions were found at 30 cm compost depths. Deeply oxidized zones substantiated observations that channel flow was occurring through some parts of the compost. The Howe Bridge site has not declined in treatment efficiency over a six year treatment life. The SAPS construction costs were equal to about seven years of NaOH chemical treatment costs and 30 years of lime treatment costs. So, if the SAPS treatment longevity is seven years or greater and comparable effluent water quality was achieved, the SAPS construction was cost effective compared to NaOH chemical treatment. Construction recommendations for SAPS include a minimum of 50 cm of compost thickness, periodic replacement or addition of fresh compost material, and increasing the number of drainage pipes underlying the limestone.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1467-7873 ISBN Medium
Area Expedition Conference
Notes Treatment of acid mine drainage by four vertical flow wetlands in Pennsylvania Evolution and remediation of acid-sulfate groundwater systems at reclaimed mine-sites; 2002-008380; References: 15; illus. incl. 5 tables United Kingdom (GBR); GeoRef; English Approved no
Call Number CBU @ c.wolke @ 16518 Serial 58
Permanent link to this record
 

 
Author (up) Dempsey, B.A.; Jeon, B.-H.
Title Characteristics of sludge produced from passive treatment of mine drainage Type Journal Article
Year 2001 Publication Geochem.-Explor. Environ. Anal. Abbreviated Journal
Volume 1 Issue 1 Pages 89-94
Keywords acid mine drainage; aerobic environment; anaerobic environment; Appalachian Plateau; Appalachians; carbonate rocks; coagulation; compressibility; decontamination; density; drainage; filtration; geochemistry; Howe Bridge; Jefferson County Pennsylvania; limestone; mining geology; North America; passive systems; Pennsylvania; pH; pollution; ponds; rates; reclamation; sedimentary rocks; settling; sludge; slurries; suspended materials; United States; viscosity; wet packing density; wetlands; zeta-potential 22, Environmental geology
Abstract In the 1994 paper by Brown, Skousen & Renton it was argued that settleability and wet-packing density were the most important physical characteristics of sludge from treatment of mine drainage. These characteristics plus zeta-potential, intrinsic viscosity, specific resistance to filtration, and coefficient of compressibility were determined for several sludge samples from passive treatment sites and for several sludge samples that were prepared in the laboratory. Sludge from passive systems had high packing density, low intrinsic viscosity, low specific resistance to filtration and low coefficient of compressibility compared to sludge that was produced after addition of NaOH.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1467-7873 ISBN Medium
Area Expedition Conference
Notes Feb.; Characteristics of sludge produced from passive treatment of mine drainage; 2002-008382; References: 29; illus. incl. 5 tables United Kingdom (GBR); GeoRef; English Approved no
Call Number CBU @ c.wolke @ 5734 Serial 57
Permanent link to this record
 

 
Author (up) 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.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8574 ISBN Medium
Area Expedition Conference
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
Permanent link to this record
 

 
Author (up) Fernandez Rubio, R.
Title Un recurso valioso las aguas de mina. A valuable resource, mine waters Type Journal Article
Year 2001 Publication Industria y Mineria Abbreviated Journal
Volume 345 Issue Pages 14-22
Keywords acid mine drainage; Africa; aquifers; case studies; East Africa; Europe; ground water; hydrogeochemical exploration; hydrogeological survey; Iberian Peninsula; injection; mining; mining geology; open-pit mining; pollution; Portugal; Southern Europe; surface mining; surface water; underground mining; water supply; water treatment; Zambia 21, Hydrogeology
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1137-8042 ISBN Medium
Area Expedition Conference
Notes Un recurso valioso las aguas de mina. A valuable resource, mine waters; 374358-2; illus. Spain (ESP); GeoRef In Process; Spanish Approved no
Call Number CBU @ c.wolke @ 5784 Serial 381
Permanent link to this record
 

 
Author (up) Foucher, S.; Battaglia-Brunet, F.; Ignatiadis, I.; Morin, D.
Title Treatment by sulfate-reducing bacteria of Chessy acid-mine drainage and metals recovery Type Journal Article
Year 2001 Publication Chemical Engineering Science Abbreviated Journal
Volume 56 Issue 4 Pages 1639-1645
Keywords Acid mine drainage Sulfate-reducing bacteria Sulfide precipitation Hydrogen transfer Fixed bed column reactor
Abstract Acid-mine drainage can contain high concentrations of heavy metals and release of these contaminants into the environment is generally avoided by lime neutralization. However, this classical treatment is expensive and generates large amounts of residual sludge. The selective precipitation of metals using H2S produced biologically by sulfate-reducing bacteria has been proposed as an alternative process. Here, we report on experiments using real effluent from the disused Chessy-les-Mines mine-site at the laboratory pilot scale. A fixed-bed bioreactor, fed with an H2/CO2 mixture, was used in conjunction with a gas stripping column. The maximum rate of hydrogen transfer in the bioreactor was determined before inoculation. kLa was deduced from measurements of O2 using Higbie and Danckwert's models which predict a dependence on diffusivity. The dynamic method of physical absorption and desorption was used. The maximum rate of H2 transfer suggests that this step should not be a limiting factor. However, an increase in H2 flow rate was observed to induce an increase in sulfate reduction rate. For the precipitation step, the gas mixture from the bioreactor was bubbled into a stirred reactor fed with the real effluent. Cu and Zn could be selectively recovered at pH=2.8 and pH=3.5, respectively. Other impurities such as Ni and Fe could also be removed at pH=6 by sulfide precipitation. Part of the outlet stream from the bioreactor was used to regulate and maintain the pH during sulfide precipitation by feeding the outlet stream back into the bioreactor. The replacement of synthetic medium with real effluent had a positive effect on sulfate reduction rate which increased by 30-40%. This improvement in bacterial efficiency may be related to the large range of oligo-elements provided by the mine-water. The maximum sulfate reduction rate observed with the real effluent was 200 mgl-1 h-1, corresponding to a residence time of 0.9 day. A preliminary cost estimation based on a treatment rate of 5 m3 h-1 of a mine effluent containing 5 gl-1 SO42- is presented.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0009-2509 ISBN Medium
Area Expedition Conference
Notes Feb.; Treatment by sulfate-reducing bacteria of Chessy acid-mine drainage and metals recovery; file:///C:/Dokumente%20und%20Einstellungen/Stefan/Eigene%20Dateien/Artikel/10064.pdf; Science Direct Approved no
Call Number CBU @ c.wolke @ 10064 Serial 54
Permanent link to this record