Biological Arsenic Removal from Mining and Milling Waters by Anaerobic Sulfate-reducing Bacteria.
Dinsdale-BE; Belin-DD; Altringer-PB
Env Issues and Waste Mgmt in Energy & Mineral Production Balkema 2:1389-1400
The U.S. Department of the Interior, Bureau of Mines Salt Lake City Research Center, is investigating biological decontamination of arsenic-bearing mining waste waters: preliminary research indicates that biological arsenic removal is possible using anaerobic sulfate- reducing bacteria indigenous to sulfate-contaminated tailings. The bacteria, grown in synthetic media containing 100 ppm as and phosphate buffer, reduced the sulfate to sulfide, and removed 88 pct of the arsenic. An arsenic sulfide compound was formed and precipitated out of solution. Although using bacteria directly is viable, the arsenic sulfide precipitates eventually redissolved at the ph levels required for cell growth. Tests have shown that remediation can be greatly enhanced by employing bacteria in a two- stage continuous flow bioreactor, which maximizes sulfide production and decreases residence time from 8 days to less than 3 hours. These promising exploratory results could lead to a practical biological process for arsenic removal from contaminated water.
Env. Issues and Waste Mgmt. in Energy & Mineral Production. Balkema, V. 2, PP. 1389-1400