British Columbia Mine Reclamation Symposium

Nitrogen and cyanide compound removal from gold mine impacted water using an anammox bioreactor Risacher, F. F.; Mancini, S.; Dollar, P.; Dennis, P.; Coffey, K.; Kennedy, C.

Abstract

The use of ammonium-nitrate fuel/oil (ANFO) explosives and cyanide in the gold mining industry can lead to elevated concentrations of nitrogen compounds in mine-impacted water, often requiring treatment before discharge. Recent limits on the concentration of ammonia added to the Canadian Metal and Diamond Mining Effluent Regulation (MDMER) further stress the need for cost-effective solutions to remove nitrogen from effluents. Nitrogen compounds are typically removed through two biological processes: 1) aerobic oxidation of ammonia, and 2) anaerobic reduction of nitrate. These processes can be costly due to the need for separate reactors, addition of a carbon source and aeration. Anaerobic ammonium oxidation (anammox) bacteria solve this issue by simultaneously converting ammonia and nitrite to nitrogen gas in a single anaerobic autotrophic process. Despite the successful application of anammox to wastewater treatment plants, little research has been done on its application to mine effluents. Here, we present an anammox-containing culture with an emphasis on its nitrogen removal capabilities as well as the microorganisms identified to carry out the metabolism. Results of our laboratory application of the culture to remove nitrate, ammonia and cyanide compounds from a gold mine effluent are presented.

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Attribution-NonCommercial-NoDerivatives 4.0 International