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Wieder, R. K. (1989). A survey of constructed wetlands for acid coal mine drainage treatment in the Eastern United States. Wetlands, 9(2), 299–315. |
Kleinmann, R. L. P. (1990). Acid Mine Water Treatment using Engineered Wetlands. Int. J. Mine Water, 9(1-4), 269–276.
Abstract: 400 systems installed within 4 years During the last two decades, the United States mining industry has greatly increased the amount it spends on pollution control. The application of biotechnology to mine water can reduce the industry's water treatment costs (estimated at over a million dollars a day) and improve water quality in streams and rivers adversely affected by acidic mine water draining from abandoned mines. Biological treatment of mine waste water is typically conducted in a series of small excavated ponds that resemble, in a superficial way, a small marsh area. The ponds are engineered to first facilitate bacterial oxidation of iron; ideally, the water then flows through a composted organic substrate that supports a population of sulfate-reducing bacteria. The latter process raises the pH. During the past four years, over 400 wetland water treatment systems have been built on mined lands as a result of research by the U.S. Bureau of Mines. In general, mine operators find that the wetlands reduce chemical treatment costs enough to repay the cost of wetland construction in less than a year. Actual rates of iron removal at field sites have been used to develop empirical sizing criteria based on iron loading and pH. If the pH is 6 or above, the wetland area (in2) required is equivalent to the iron. load (grams/day) divided by 10. Theis requirement doubles at a pH of 4 to 5. At a pH below 4, the iron load (grams/day) should be divided by 2 to estimate the area required (in2).
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Kleinmann, R. L. P. (1990). Biological treatment of acid mine water using engineered wetlands. |
Brooks, R. P., Unz, R. F., Davis, L. K., Tarutis, W. J., & Yanchunas, J. (1990). Long-term removal and retention of iron and manganese from acidic mine drainage by wetlands.147.
Abstract: A promising low-technology solution for treating acidic mine drainage (AMD) emanating from coal mined lands involves the use of constructed wetlands.^The research was directed at addressing questions about retention mechanisms for the long-term storage of iron and manganese in constructed wetlands dominated by broad-leaved cattails (Typha latifolia).^Three sites in central Pennsylvania spanning the range of water chemistry parameters found in AMD were investigated.^When the AMD was circumneutral, and metal loadings were low, 79% of the iron, and 48% of the manganese were retained on average.^In the highly acidic site (pH approx.^= 3), < 10% of the metal loadings were retained.^The primary retention mechanism appears to be the formation of metal oxides in the aerobic zones of the sediments.^Although most microbial isolates extracted from sediment cores originated in the aerobic portions of the sediments, there was no evidence that they were transforming metals.^When AMD is circumneutral and metal loadings are low, constructed wetlands can be an effective approach to treating mine drainage.^At sites with highly acidic waters and high metal loadings, the use of constructed wetlands to treat AMD may be ineffectual, and should be implemented with caution.
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Norton, P. J. (1992). The Control of Acid Mine Drainage with Wetlands. Mine Water Env., 11(3), 27–34.
Abstract: The recent increases in environmental legislation, especially in the USA'have meant that there is a need on behalf of the mining companies for more judicious operational planning and more thorough restoration techniques in order to reduce costs and prevent violation of the smctly enforced regulations. Water pollution is probably the greatest problem and many less enlightened operators, especially for example, in surface coal milling in Pennsylvania, have been forced into liquidation after having been unable to meet the severe restrictions on Acid Mine Drainage (AMD). The problems of AMD are also inherent in most forms of metalliferous and coal mining and also in some types of aggregate quarrying. As excavations go deeper in search of ever diminishing reserves then they are more likely to encounter groundwater which can become polluted if insufficient care is not taken. It is to be expected that the laws will also become more severe than they are at present in Europe and methods of treatment of AMD will need to be developed that are more efficient than the costly chemical methods currently used. Research by the author and others into the source of AMD pollution and its treatment with engineered wetlands and other operational methods are discussed in the paper. The methods have- the distinct benefit that they are cheap to install, are cost effective over a long period with the minimum of supervision and are environmentally acceptable to the planning and regulatory authorities.
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