Michaud, L. H. (1994). Recent technology related to the treatment of acid drainage. Earth and Mineral Sciences, 63(3), 53–55.
Abstract: The generation of acid mine drainage is a serious environmental problem associated with coal mining. The chemistry of acid mine drainage is outlined. The prevention and minimization of acid mine drainage formation is examined. The in situ inhibition and remediation of acid mine drainage is described. Methods for the passive treatment of acid mine drainage after formation are discussed. The design of treatment systems is considered. -P.M.Taylor
|
|
Bochkarev, G. R., Beloborodov, A. V., Kondrat'ev, S. A., & Pushkareva, G. I. (1994). Intensification of Aeration in treating Natural-Water and Mine Water. J. Min. Sci., 30(6), 5.
|
Stefanoff, J. G., & Kim, Y. K. (1994). Reduction of leachability of heavy metals in acid mine drainage. J. Environ. Sci. Health Part A Environ. Sci. Eng., 29(2), 371–388.
Abstract: The leaching characteristics of sludges from the treatment of acid mine drainage(AMD) from Iron Mountain Mine near Redding, California were compared using two different processes: caustic soda treatment and a modified lime/sulfide treatment process. The modified lime/sulfide process produced a sludge with better dewaterability characteristics than sludge from the caustic soda process. The results of the Cal WET indicated that the modified lime/sulfide process sludge had less leachability than that of sludge from the caustic soda process. Both processes could achieve a substantial reduction of heavy metals in leachate to levels below the federal regulatory limits(TCLP). For cadmium and zinc, however, neither process produced a sludge that met the requirements of the Cal WET procedure.
|
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.
|
Bechard, G. (1994). Use Of Cellulosic Substrates For The Microbial Treatment Of Acid-Mine Drainage. Journal of Environmental Quality, 23(1), 111–116.
Abstract: A mixed aerobic-anaerobic microbial treatment process was developed previously for acid mine drainage (AMD) using straw as a substrate. The process was effective only if AMD was supplemented with sucrose. The present study was conducted to determine which, if any, of three cellulosic materials could sustain the microbial treatment of AMD without the addition of a sucrose amendment and to determine the effect of the retention time on the performance of the reactors. The performance of small reactors that treated simulated AMD in the continuous mode was evaluated using alfalfa (Medicago sativa L.) hay, timothy (Phleum pratense L.) hay, and straw with a 5 d retention time. Parameters measured were pH, Fe, Al, sulfate, and ammonium. Timothy hay and straw sustained AMD mitigation for 3 wk, and thereafter all activity ceased. After the reactors ceased treating AMD, the mitigative activities were reinitiated by the addition of sucrose, but not by urea. Alfalfa sustained AMD mitigation for a longer time period than either straw or timothy. The effect of three retention times, 3.5, 7, and 35 d, was then investigated for reactors containing fresh alfalfa. Increasing the retention time resulted in better metal removal and a greater pH increase. With a 7-d retention time, 75 L of simulated AMD were neutralized from a pH of 3.5 to a pH value greater than 6.5. Reactors operating with a 3.5-d retention time treated only 58.3 L of simulated AMD before failing. Ammonium was detected in effluents of active reactors. The results of this study indicate that a low maintenance microbial treatment system can be developed with alfalfa as a substrate without the addition of a sucrose amendment.
|
