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Fisher, T. S. R., & Lawrence, G. A. (2006). Treatment of acid rock drainage in a meromictic mine pit lake. Journal of environmental engineering, 132(4), 515–526.
Abstract: The Island Copper Mine pit near Port Hardy, Vancouver Island, B.C., Canada, was flooded in 1996 with seawater and capped with fresh water to form a meromictic (permanently stratified) pit lake of maximum depth 350 m and surface area 1.72 km2. The pit lake is being developed as a treatment system for acid rock drainage. The physical structure and water quality has developed into three distinct layers: a brackish and well-mixed upper layer; a plume stirred intermediate layer; and a thermally convecting lower layer. Concentrations of dissolved metals have been maintained well below permit limits by fertilization of the surface waters. The initial mine closure plan proposed removal of heavy metals by metal-sulfide precipitation via anaerobic sulfate-reducing bacteria, once anoxic conditions were established in the intermediate and lower layers. Anoxia has been achieved in the lower layer, but oxygen consumption rates have been less than initially predicted, and anoxia has yet to be achieved in the intermediate layer. If anoxia can be permanently established in the intermediate layer then biogeochemical removal rates may be high enough that fertilization may no longer be necessary. < copyright > 2006 ASCE.
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(2006). World first: Full-scale BioSure plant commissioned. Water Wheel, 5(3), 19–21.
Abstract: ERWAT's Ancor Wastewater Treatment Works on the Far East Rand commissioned a 10 Ml/day full-scale plant to treat toxic mine-water from the Grootvlei gold mine using primary sewage sludge. The R15-million plant is treating sulphate rich acid mine drainage using the Rhodes BioSURE Process. First, the pumped mine-water is treated at a high-density separation (HDS) plant to remove iron and condition pH levels. Then it is pumped two km via a newly-constructed 10 Ml capacity pipeline to the Ancor works. This mine-water is then mixed together with primary sewage sludge in a mixing tank from where a splitter box directs the material to eight biological sulphate reducing reactors or bioreactors. The overflow water which is rich in sulphide is pumped through the main pump station to another mixing box. Here, iron slurry is mixed with the material before it is again divided between four reactor clarifiers for sulphide removal. The overflow water, now containing reduced sulphate levels and virtually no sulphide is pumped to Ancor's biofilters for removal of remaining Chemical Oxygen Demand (COD) and ammonia following the conventional sewage treatment process for eventual release into the Blesbokspruit.
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Curi, A. C., Granda, W. J. V., Lima, H. M., & Sousa, W. T. (2006). Zeolites and their application in the decontamination of mine waste water. Informacion Tecnologica, 17(6), 111–118.
Abstract: This paper describes the genesis, structure and classification of natural zeolites, including their most relevant properties such as porosity, adsorption and ionic exchange. The use of natural zeolites in the treatment of effluents containing heavy metals is reviewed based on current literature. These uses are focused on mineral-metallurgical effluents and mercury pollution related to artisan mining activities. The study shows that natural zeolites are efficient in removal of heavy metals in metal mining effluents, can be produced and improved at a low cost, and can also be used to adsorb mercury vapors from ovens used to fire amalgams.
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