Bioleaching of As from mine tailings using an autochthonous Bacillus cereus strain

Contamination of heavy metals has been a serious environmental problem due to increasing anthropogenic activities such as mining, smelting, livestock, landfills, waste dumps, and agriculture. Bioleaching experiments were conducted using native Bacillus cereus MAMPE19 BCG, isolated characterized from previous research, test removal arsenic (As) actual mining waste. Mineralogical characterization by XRD was performed identify mineral associations with As. The experimental design included bioleaching system agitated flasks (triplicate) the effects pH (5, 7, 9) pulp density (10, 15, 20%) evaluated. Finally, based on results ANOVA, that achieved highest percentage As dissolution selected scaled stirred tank bioreactor. composition mainly calcite (CaCO3), gismondine (CaAl2Si2O8·4(H2O)), akermanite (Ca2MgSi2O7), silicon oxide (SiO2). Native dissolved 40.6 ± 4.9 37.4 2.7 % in 10 d, at 5 15%, respectively; 27.5 2.9% bioreactor supported significant statistical differences.