| Home | << 1 2 3 4 5 6 7 8 9 10 >> [11–20] |
|
Dempsey, B. A., & Jeon, B. - H. (2001). Characteristics of sludge produced from passive treatment of mine drainage. Geochem.-Explor. Environ. Anal., 1(1), 89–94.
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.
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
|
|
Demchak, J., Morrow, T., Skousen, J., Donovan, J. J., & Rose, A. W. (2001). Treatment of acid mine drainage by four vertical flow wetlands in Pennsylvania Evolution and remediation of acid-sulfate groundwater systems at reclaimed mine-sites. Geochemistry – Exploration, Environment, Analysis, 1(1), 71–80.
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.
|
|
Smit, J. P., & Pretorius, L. E. (2000). The treatment of polluted mine water. J. Afr. Earth Sci., 31(1), 72.
|
|
Märten, H. (2006). Neueste Trends zur aktiven Wasserbehandlung und Anwendungsbeispiele. Wissenschaftliche Mitteilungen, 31, 13–22.
Abstract: Aktuelle Entwicklungen auf dem Gebiet der aktiven Wasserbehandlung im Bergbau in den spezifischen Anwendungsgebieten • Behandlung von sauren Bergbauwässern (AMD – acidic mine drainage) mit Schwerpunkt HDS-Technologie (HDS – high-density sludge) • In-situ-Behandlung bergbaubeeinflusster Grundwasserkörper, insbesondere nach Anwendung der In-situ-Laugung (ISL) • In-situ-Behandlung von Tagebaurestseen mit Schwerpunkt In-lake-Verfahren werden hinsichtlich Machbarkeit, technologischer Kenngrößen und Effizienz bewertet und kommen-tiert. Recent developments in the field of active water treatment technologies in the mining sector are re-viewed. Application areas of interest include • Treatment of acidic mine drainage (AMD) emphasizing HDS technology (HDS – high-density sludge) • In-situ treatment of groundwater affected by mining, in particular after the application of in-situ leaching (ISL) • In-situ treatment of lakes arising in former open-pit lignite mines, in particular the application of in-lake methods The various applications are evaluated with regard to feasibility, technical characteristics and treat-ment efficiency.
|
|
Janneck, E., Schlee, K., Arnold, I., & Glombitza, F. (2006). Einsatz neuer Belüftungssysteme zur Effizienzsteigerung bei der Grubenwasserbehandlung in der Lausitz. Wissenschaftliche Mitteilungen, 31, 29–35.
Abstract: Im Beitrag wird über Erfahrungen und Ergebnisse berichtet, wie durch den Einsatz neuer Belüftungssysteme eine deutliche Stabilisierung des Prozesses der Eisenabtrennung in der GWRA Schwarze Pumpe erreicht wurde. Erstmals wurden im Lausitzer Revier Wendelbelüfter im Prozess der Grubenwasserreinigung eingesetzt. Unter Bedingungen, bei denen die Sauerstoffdiffusion der geschwindigkeitsbestimmende Schritt ist, bewirken diese Geräte eine deutliche Beschleunigung der Eisenoxidation. Als zusätzliche Effekte, die zur Effizienzsteigerung der Grubenwasserbehandlung beitragen, können eine wesentliche Durchsatzsteigerung, eine bessere Kalkausnutzung sowie eine deutlich verbes-serte Schlammeindickung genannt werden. The article presents experiences and results of the application of new aerator-systems in the mine water treatment. The processes of ferrous iron oxidation and sludge removal became more stable and efficiently by the application of the aerators. For the first time, spiral aerators were used in the Lower Lusatia lignite mining district to clean ferrous iron containing mine water. These devices lead to an enhanced iron oxidation rate under the existing conditions, where the oxygen diffusion is the rate determining step. Furthermore, the application caused increased throughput, optimal lime utilisation and better sludge thickening, which led to a higher efficiency of the mine water treatment.
|