title: Treatment of percolate from metal sulfide mine tailings with a permeable reactive barrier of transformed red mud.
abstract: Metal sulfide tailings of the Sardinian (Italy) abandoned Baccu Locci arsenic mine show high concentrations of aluminum, arsenic, cadmium, copper, manganese, lead, and zinc in acid percolate (pH = 4) and have been classified as "dangerous waste." This paper shows that the release of toxic metals can be strongly reduced when the tailings are placed on a reactive permeable bed (7 wt %) of porous, alkaline pellets of transformed red mud (TRM). During a laboratory percolation test, two columns with 80 kg of waste, of which one contained a bottom layer of TRM pellets, were each alimented with 600 L of de-ionized water. Comparing pH, electroconductivity, metal, and sulfate concentrations of collected percolate from both columns demonstrates efficient neutralization (pH = 7.4) and removal of metals (80 to 99%) for the column with the permeable reactive bottom layer.
authors.affiliation: Virotec Italia s.r.l., Rome, Italy.
authors.forename: J J P
authors.initials: JJ
authors.lastname: Zijlstra
authors.forename: R
authors.initials: R
authors.lastname: Dessì
authors.forename: R
authors.initials: R
authors.lastname: Peretti
authors.forename: A
authors.initials: A
authors.lastname: Zucca
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D007220:Industrial Waste; D008906:Mining; D013440:Sulfides / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D002614:Chelating Agents; D007220:Industrial Waste; D013440:Sulfides