|
|
Kepler, D. A., & Mc Cleary, E. C. (1994). Successive Alkalinity-Producing Systems (SAPS) for the Treatment of Acid Mine Drainage. Proceedings, International Land Reclamation and Mine Drainage Conference, 1, 195–204.
Abstract: Constructed wetland treatment system effectiveness has been limited by the alkalinity-producing, or acidity-neutralizing, capabilities of systems. Anoxic limestone drains (ALD's) have allowed for the treatment of approximately 300 mg/L net acidic mine drainage, but current design guidance precludes using successive ALD's to generate alkalinity in excess of 300 mg/L because of concerns with dissolved oxygen. “Compost” wetlands designed to promote bacterially mediated sulfate reduction are suggested as a means of generating alkalinity required in excess of that produced by ALD's. Compost wetlands create two basic needs of sulfate reducing bacteria; anoxic conditions resulting from the inherent oxygen demand of the organic substrate, and quasi-circumneutral pH values resulting from the dissolution of the carbonate fraction of the compost. However, sulfate reduction treatment area needs are generally in excess of area availability and/or cost effectiveness. Second generation alkalinity-producing systems demonstrate that a combination of existing treatment mechanisms has the potential to overcome current design concerns and effectively treat acidic waters ad infinitum. Successive alkalinity-producing systems (SAPS) combine ALD technology with sulfate reduction mechanisms. SAPS promote vertical flow through rich organic wetland substrates into limestone beds beneath the organic compost, discharging the pore waters. SAPS allow for conservative wetland treatment sizing calculations to be made as a rate function based on pH and alkalinity values and associated contaminant loadings. SAPS potentially decrease treatment area requirements and have the further potential to generate alkalinity in excess of acidity regardless od acidity concentrations.
|
|
|
|
Ericsson, B., & Hallmans, B. (1994). Treatment and Disposal of Saline Waste-water from Coal-mines in Poland. Desalination, 98(1-3), 239–248.
Abstract: Some Polish coal mines are reviewed with respect to the disposal of saline wastewater into rivers and its environmental impact. The drainage water from mines has a daily contribution of, in the order of magnitude, 6,500 tons chlorides (Cl-) and 0.5 tons sulphates (SO42-) to the rivers Wisla and Odra. The river Wisla contributes to about 55 % of the water resources in Poland. This report is based on a part of a commission for the Ministry of Environmental Protection, National Resources and Forestry ofPoland by COWI-VBB VIAK joint venture.Different treatment and disposal schemes are described and compared from a technical-economical point of view, out of which methods for desalination with zero discharge as well as deep well injection are the most promising ones.The desalination methods include reverse osmosis (RO) plant, thermal powered desalination and crystallization plant as well as facilities for dewatering and drying of sodium chloride (NaCl) to be sold in Poland and/or on the export market, The valuable main products are potable water, boiler feed water and sodium chloride. A special problem in this connection may be the radioactivity in the wastewater from some of the mines. Special treatment methods for radioactivity removal in the selected treatment and disposal scheme for the mine wastewater are discussed with respect to the effects of radioactivity on the saleability of the recovered salt. In addition methods for recovery of the by-products magnesium hydroxide, iodine and bromine are considered from the point of view of economy and environmental protection.Finally, the desalination project in Katowice for the coal mines Debiensko and Budryk is now in the end of the construction phase. Some modifications of the original design ace shown.
|
|
|
|
Murdock, D. J., Fox, J. R. W., & Bensley, J. G. (1994). Treatment of acid mine drainage by the high density sludge process. In Special Publication – United States. Bureau of Mines, Report: BUMINES-SP-06A-94 (pp. 241–249). Proceedings of the International land reclamation and mine drainage conference and Third international conference on The abatement of acidic drainage; Volume 1 of 4; Mine drainage.
|
|
|
|
Eger, P. (1994). Wetland Treatment for Trace-metal Removal from Mine Drainage – the Importance of Aerobic and Anaerobic Processes. Water Sci. Technol., 29(4), 249–256.
Abstract: When designing wetland treatment systems for trace metal removal, both aerobic and anaerobic processes can be incorporated into the final design. Aerobic processes such as adsorption and ion exchange can successfully treat neutral drainage in overlandflow systems. Acid drainage can be treated in anaerobic systems as a result of sulfate reduction processes which neutralize pH and precipitate metals.Test work on both aerobic and anaerobic systems has been conducted in Minnesota. For the past three years, overland flow test systems have successfully removed copper, cobalt, nickel and zinc from neutral mine drainage. Nickel, which is the major contaminant, has been reduced around 90 percent from 2 mg/L to 0.2 mg/L. A sulfate reduction system has successfully treated acid mine drainage for two years, increasing pH from 5 to over 7 and reducing concentrations of all metals by over 90 percent.Important factors to consider when designing wetlands to remove trace metals include not only the type of wetlandrequired but also the size of the system and the residence time needed to achieve the water quality standards.
|
|
|
|
Fraser, W. W., & Robertson, J. D. (1994). Subaqueous disposal of reactive mine waste; an overview and update of case studies; MEND, Canada. In Special Publication – United States. Bureau of Mines, Report: BUMINES-SP-06A-94 (pp. 250–259). Proceedings of the International land reclamation and mine drainage conference and Third international conference on The abatement of acidic drainage; Volume 1 of 4; Mine drainage.
|
|
