A novel bioreactor system for simultaneous mutli-metal leaching from industrial pyrite ash: Effect of agitation and sulphur dosage

PANDA S. , Akcil A. , MISHRA S. , ERUST C.

JOURNAL OF HAZARDOUS MATERIALS, vol.342, pp.454-463, 2018 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 342
  • Publication Date: 2018
  • Doi Number: 10.1016/j.jhazmat.2017.08.038
  • Page Numbers: pp.454-463
  • Keywords: Pyrite ash, Bioreactor, Sulphur oxidation, Agitation, Mutli-metal leaching, ACIDOPHILIC BACTERIA, MIXED CULTURE, CHALCOPYRITE, WASTE, ZN, REMOVAL, COPPER, PLANT, ORES, CU


Simultaneous multi-metal leaching from industrial pyrite ash is reported for the first time using a novel bioreactor system that allows natural diffusion of atmospheric O-2 and CO2 along with the required temperature maintenance. The waste containing economically important metals (Cu, Co, Zn &As) was leached using an adapted consortium of meso-acidophilic Fe2+ and S oxidising bacteria. The unique property of the sample supported adequate growth and activity of the acidophiles, thereby, driving the (bio) chemical reactions. Oxido-reductive potentials were seen to improve with time and the system's pH lowered as a result of active S oxidation. Increase in sulphur dosage (>1 g/L) and agitation speed (>150 rpm) did not bear any significant effect on metal dissolution. The consortium was able to leach 94.01% Cu (11.75% dissolution/d), 98.54% Co (12.3% dissolution/d), 75.95% Zn (9.49% dissolution/d) and 60.80% As (7.6% dissolution/d) at 150 rpm, 1 g/L sulphur, 30 degrees C in 8 days. (C) 2017 Elsevier B.V. All rights reserved.