|
|
Ntengwe, F. W. (2005). An overview of industrial wastewater treatment and analysis as means of preventing pollution of surface and underground water bodies – The case of Nkana Mine in Zambia. Phys. Chem. Earth, 30(11-16 Spec. Iss.), 726–734.
Abstract: The wastewaters coming from mining operations usually have low pH (acidic) values and high levels of metal pollutants depending on the type of metals being extracted. If unchecked, the acidity and metals will have an impact on the surface water. The organisms and plants can adversely be affected and this renders both surface and underground water unsuitable for use by the communities. The installation of a treatment plant that can handle the wastewaters so that pH and levels of pollutants are reduced to acceptable levels provides a solution to the prevention of polluting surface and underground waters and damage to ecosystems both in water and surrounding soils. The samples were collected at five points and analyzed for acidity, total suspended solids, and metals. It was found that the pH fluctuated between pH 2 when neutralization was forgotten and pH 11 when neutralization took place. The levels of metals that could cause impacts to the water ecosystem were found to be high when the pH was low. High levels of metals interfere with multiplication of microorganisms, which help in the natural purification of water in stream and river bodies. The fish and hyacinth placed in water at the two extremes of pH 2 and pH 11 could not survive indicating that wastewaters from mining areas should be adequately treated and neutralized to pH range 6-9 if life in natural waters is to be sustained. < copyright > 2005 Elsevier Ltd. All rights reserved.
|
|
|
|
Barton, C. D. (1999). Renovation of a failed constructed wetland treating acid mine drainage. Environmental Geology, 39(1), 39–50.
Abstract: Acid mine drainage (AMD) from abandoned underground mines significantly impairs water quality in the Tones Branch watershed in McCreary Co., Kentucky, USA. A 1022-m(2) surface-flow wetland was constructed in 1989 to reduce the I AMD effects, however, the system failed after six months due to insufficient utilization of the treatment area, inadequate alkalinity production and metal overloading. In an attempt to improve treatment efficiencies, a renovation project was designed incorporating two anoxic limestone drains (ALDs) and a series of anaerobic subsurface drains that promote vertical now or mine water through a successive alkalinity producing system (SAPS) of limestone beds overlain by organic compost. Analytical results from the 19-month post-renovation period are very encouraging. Mean iron concentrations have decreased from 787 to 39 mg l(-1), pH increased from 3.38 to 6.46 and acidity has been reduced from 2244 to 199 mg l(-1) (CaCO3 equivalent). Mass removal rates averaged 98% for Al, 95% for Fe, 94% for acidity, 55% for sulfate and 49% for Mn during the study period. The results indicate increased alkalinity production from limestone dissolution and longer residence time have contributed to sufficient buffering and metal retention. The combination of ALDs and SAPS technologies used in the renovation and the sequence in which they were implemented within the wetland system proved to be an adequate and very promising design for the treatment of this and other sources of high metal load AMD.
|
|
|
|
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.
|
|
|
|
Naugle, W. K. (2003). Remediation of the Eagle Mine superfund site: a biological success story. Tailings and Mine Waste '03, , 481–485.
Abstract: Remediation of the Eagle Mine Superfund Site began in 1988. Remedial action included: bulk-heading adits, flooding mine workings; constructing diversion ditches around waste rock; consolidating mine wastes in an on-site tailings pile; capping the tailings pile with a multi-layer, engineered cap; and revegetating disturbed areas with native plants. Flooding the mine workings resulted in unacceptable seepage into the Eagle River in late 1989. A water treatment plant was constructed to collect mine seepage and groundwater at the main tailings pile. In October 2001, construction of the remedy was declared “complete” and the site is now in the operation, maintenance and monitoring phase. A strong downward trend in zinc and cadmium concentrations in the Eagle River has occurred and, trout and macroinvertebrate populations have increased. Biological data are being used to establish water quality standards for the Eagle River.
|
|
|
|
Angelos, M. A. F. (2000). Rehabilitation options for a Finnish copper mine. International Conference on Practical Applications in Environmental Geotechnology Ecogeo 2000, 204, 207–214.
Abstract: The Luikonlahti Copper mine is located near the town of Kaavi in eastern Finland, approximately 30 km northwest of Outokumpu. The copper sulphide ore deposit formed the northern most part of the Outokumpu assemblage. During 15 years of operation, between 1968 and 1983, a total of 33 km of underground tunnels and 5.5 km of underground shafts were excavated in the mining of 6.85 million metric tons of ore. The underground working are now flooded with 2 million m(3) of contaminated water and three open pits contain over 1 million m(3) of contaminated water. Five separate waste rock piles exist and are actively forming acid mine drainage (AMD).
|
|
