Possibility of bacterial leaching of antimony, chromium, copper, manganese, nickel, and zinc from contaminated sediment

•Leaching rate of Sb was very low in comparison to other heavy metals.•The highest removal efficiency was gained for Ni (97.4%) and Mn (95.2%).•Metal removal efficiency was mainly influenced by metal partitioning in sediment.•Bioleaching led to stable and non-bioavailable forms of metals in treated residue.•The addition of Ag ion did not enhance the metal solubilization efficiencies.

There is an environmental risk of Sb becoming a major pollutant due to the quick increase in the production of Sb industry. However, there have been few investigations on interactions between Sb and microorganisms and bioremediation of Sb this paper presents an investigation on bioleaching of Sb from contaminated sediment which is collected in the vicinity of a Sb processing plant using the iron-oxidizer, Acidithiobacillus ferrooxidans. The bioleaching of Cr, Cu, Mn, Ni, and Zn in the sediment was also investigated to compare with that of sb. Duplicated batch-type experiments based on different incubation time, on the presence or absence of Fe2+ and/ or Ag+, were conducted to compare the efficiency of metal extraction. After bioleaching, 97.4% of Ni, 95.2% of Mn, 65.8% of Cr, 36.2% of Cu, 34.8% of Zn, and 2.2% of Sb were extracted from sediments. The extraction efficiency of Sb was the lowest in comparison to those of Cr, Cu, Mn, Ni, and Zn. This result indicated that Sb is difficult to solubilize by bacterial leaching. The catalytic effect of Ag+ was not observed, which could be due to the inhibition of Ag+ on the activity of A. ferrooxidans and formation of Ag jarosite precipitation on the surface of sediment particles. Though the extraction of Sb was not efficient, this study demonstrates the potential for Sb to be bioleached and a feasible technique in remediation of Sb.