|
|
Guay, R. (1999). Effect of flooding of oxidized mine tailings on T-ferrooxidans and T-thiooxidans survival and acid mine drainage production: a 4 year restoration-environmental follow-up. Biohydrometallurgy and the Environment toward the Mining of the 21st Century, Pt B 1999, 9, 635–643.
Abstract: A pilot-scale study on the effect of flooding unoxidized and oxidized Cu/Zn tailings demonstrated the technical feasability of this technology to remediate a mining site where over 3 million tons of tailings were impounded. Full-scale flooding of the tailing pond with free running water was undertaken after the construction of an impervious dam; approximately 2 million m(3) of surface water at pH 7,4 completely covered the tailings after 16 months. The minimal water column over the tailings was established at 1,20 m and reached 4,5 m, depending on the site topography. Water and tailings samples were collected from 9 different locations from the surface of the man-made lake using a specially designed borer and were analyzed for pH, conductivity, iron- and sulfur-oxidizing bacteria activity and numbers as well as the sulfate reducing bacteria (SRB) population. We showed that over a four year period of flooding, the overall population of iron-oxidizers decreased considerably; their numbers drastically fell from 1 x 10(6) to 1 x 10(2) active cells per g of oxidized tailings while the SRBs increased from 10(1) to 10(5)/g. The pH of the influent, the reservoir and the effluent water remained fairly constant between 6,9 up to 7,4 over the entire period. During this time, interstitial water pH increased from 2,9 to 4,3 in flooded tailings where lime could not be incorporated in the first 20 cm of tailings; elsewhere, the pH of the tailings suspensions remained fairly constant around neutral values (pH 7,0). Dissolved oxygen was measured at fixed intervals and remained also constant between 6 and 7.5 mg/L while water temperatures fluctuated below freezing point to +20C respectively in winter and summer season.
|
|
|
|
O'Sullivan, A. D., McCabe, O. M., Murray, D. A., & Otte, M. L. (1999). Wetlands for rehabilitation of metal mine wastes. Biology and Environment-Proceedings of the Royal Irish Academy, 99b(1), 11–17.
Abstract: Aspects of research work undertaken by the Wetland Ecology Research Group at University College Dublin are summarised here. Wastes from mining activities generally contain high concentrations of heavy metals and other toxic substances. Reclamation methods to treat these wastes include the use of wetlands, for revegetation of mine tailings under flooded conditions and for the treatment of tailings water. Both natural and constructed wetlands are frequently employed for the treatment of mine wastes. Through a complex array of plant, soil and microbial interactions contaminants, such as heavy metals and sulphates, can be successfully removed from wastewater. Suitable vegetation can stabilise the tailings sediment, thereby preventing it from being dust-blown or leached into the surrounding environment. Our research suggests that these two techniques for treatment of mine wastes are successful and economically viable.
|
|
|
|
Zaluski, M. (1999). Design and construction of bioreactors with sulfate-reducing bacteria for acid mine drainage control. Phytoremediation and Innovative Strategies for Specialized Remedial Applications, , 205–210.
Abstract: At many abandoned mine sites in the Western U.S., conventional treatment of AMD is not feasible due to the of lack of power and limited site accessibility. Therefore, three bioreactors were built at an abandoned mine site in Montana to demonstrate feasibility of treating AMD using sulphate reducing bacteria (SRB) in a passive water treatment train. The SRB are capable of increasing the pH and reducing the load of dissolved metals in the effluent. The reactors, constructed in the Fall of 1998, were designed to evaluate the SRB technology applied under different environmental conditions. Each bioreactor was designed with mechanisms to enable simulation of seasonal dry and wet climatic conditions. Two bioreactors were placed in trenches and one was constructed above the ground to investigate impact of seasonal freezing and thawing on SRB activity. Two bioreactors contain a passive pretreatment section to increase pH of water before the AMD enters the bioreactor chamber.
|
|
|
|
Henderson, A. (1998). The implementation of paste fill at the Henty Gold Mine. Minefill'98, 98(1), 299–304.
Abstract: The Henty Gold Mine, located ill Western Tasmania uses innovative solutions to effectively manage a mining operation in an environmentally sensitive setting and has been presented with several environmental awards. Fill is required as part of the mining method to provide passive ground support, minimise rock exposure and ensure maximum recovery of the small but high-grade orebody. The use of the whole portion of leach residue in the backfill reduces the surface tailing disposal requirements. Therefore, High Density Paste Fill (HDPF) has been selected as the most appropriate fill method to meet these objectives. Additional benefits include the minimisation of excess water from fill and the subsequent need for the collection and treatment of water and slimes. There are minimal equipment requirements during placement, thereby optimising mine resources for production.
|
|
|
|
Wiessner, A. (1998). The treatment of a deposited lignite pyrolysis wastewater by adsorption using activated carbon and activated coke. Colloids and Surfaces a-Physicochemical and Engineering Aspects, 139(1), 91–97.
Abstract: To study the functions of activated carbon and activated coke adsorption for the treatment of highly contaminated discolored industrial wastewater with a wide molecular size distribution of organic compounds, the deposited lignite pyrolysis wastewater from a filled open-cast coal mine was used for continuous and discontinuous experiments.
|
|
