Technologies and potential technologies for removing arsenic from process and mine wastewater

An extensive review of the literature has been performed to identify appropriate technologies for the removal of arsenic from a variety of wastewaters. The identified treatments include technologies now being utilized and technologies that show good potential for being implemented in the near future. The technologies discussed in detail in this paper include the two most used unit operations, i.e., precipitation and adsorption. Ion exchange, solvent extraction, nanofiltration, foam flotation, and biological technologies have also been reviewed. These technologies are referenced in this paper but detailed discussions are presented elsewhere. The emphasis of this presentation is removal of arsenic from mine waters. Ferrihydrite, aluminium hydroxide, alumina, and carbon adsorption of arsenic are discussed in detail. Also, a relatively new precipitation technology based on the formation of arsenic bearing hydroxyapitate is discussed. Pilot and bench-scale demonstration studies conducted for the U.S. EPA Minewaste Technology Program for the removal of arsenic From a variety of wastewaters will be described and the successful results summarized (<20 mu g/Liter), e.g., the results from demonstrations applied to a mining operation groundwater, and to a lead smelter scrubber and process water will be presented.