Development of a passive bioremediation process based on sulfate-reduction to treat arsenic-containing acidic mine water

Abstract : Arsenic (As) is one of the priority pollutants commonly associated with mine tailings and Acid Mine Drainages (AMD). A bioprocess based on the activity of acido-tolerant sulfate-reducing bacteria (SRB) was studied at laboratory scale in order to precipitate arsenic sulfide. Enrichments of SRB were obtained from sediments of Carnoulès mining site in France. The enriched SRB-containing community was used to inoculate a bioreactor subsequently fed with a synthetic solution, its composition miming that of the Carnoulès AMD. The substrates were immobilized inside the bioreactor in order to treat water in a passive way. Results show the feasibility of selective precipitation of arsenic versus iron in a passive bioreactor fed with AMD.