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.
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Botha, G. R., Sanderson, R. D., & Buckley, C. A. (1992). Brief Historical Review of Membrane-development and Membrane Applications in Waste-water Treatment in Southern Africa. Water Sci. Technol., 25(10), 1–4.
Abstract: Away back in 1953 few people in the world, let alone South Africa, knew or had heard about membrane desalination, but there was an increasing awareness that electrodialysis had considerable potential for the desalination of brackish water.In South Africa the development of the new gold fields in the northern Orange Free State and the problems posed by the presence of excessive volumes of very saline mine waters stimulated interest in desalination and the CSIR* in collaboration with the mining industry became involved in the development of the electrodialysis process. By 1959 the largest brackish desalination plant in the world had been built and commissioned. South Africans were thus in the forefront of this technology, even to the extent of making the required membranes locally.Our historical review of membrane development and the applications of membrane technology in Southern Africa encompasses both pressure- and voltage-driven processes. Examples of the pressure processes are microfiltration, ultrafiltration and charged membrane ultrafiltration or nanofiltration, and finally reverse osmosis with fixed and dynamically formed membranes. The voltage-drive processes considered are electrodialysis and electrodialysis reversal.
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