The simultaneous removal of arsenic and manganese at a gold mine in Nevada

摘要

Arsenic, which occurs naturally in many parts of the earth, is commonly released into the environment from mining activities. Not only is arsenic acutely toxic towards human health at higher levels, low level chronic exposure and ingestion of arsenic is also a major human health concern and can lead to various diseases, including diabetes and cancer. The latest research also shows that arsenic can act as a potent endocrine disrupter and adversely impact hormone functions in humans. The paper highlights a case study at a gold mine in Nevada where water with arsenic levels up to 4 mg/L were treated down to below 50 μg/L, and manganese levels were treated down to below 100 μg/L, using existing infrastructure at a water treatment plant by changing the treatment process configurations. Both bench scale testing results and full-scale water treatment plant data and analyses are presented, and the rationale for the refinement and changes to the arsenic removal treatment processes are discussed. Studies of the water chemistry and the adjustments of both the treatment chemicals used and the treatment procedures, such as the chemical addition points, are also presented, and the challenges for the simultaneous removal of manganese and arsenic as well as the relevant water chemistry behind the treatment processes are also discussed.