Sulfate and metal removal from acid mine drainage using sugarcane vinasse as electron donor: Performance and microbial community of the down-flow structured-bed bioreactor

Made available in DSpace on 2021-06-25T10:25:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 The down flow structured bed bioreactor (DFSBR) was applied to treat synthetic acid mine drainage (AMD) to reduce sulfate, increase the pH and precipitate metals in solutions (Co, Cu, Fe, Mn, Ni and Zn) using vinasse as an electron donor for sulfate-reducing bacteria (SRB). DFSBR achieved sulfate removal efficiencies between 55 and 91%, removal of Co and Ni were obtained with efficiencies greater than 80%, while Fe, Zn, Cu and Mn were removed with average efficiencies of 70, 80, 73 and 60%, respectively. Sulfate reduction increased pH from moderately acidic to 6.7–7.5. Modelling data confirmed the experimental results and metal sulfide precipitation was the mainly responsible for metal removal. The main genera responsible for sulfate and metal reduction were Geobacter and Desulfovibrio while fermenters were Parabacteroides and Sulfurovum. Moreover, in syntrophism with SRB, they played an important role in the efficiency of metal and sulfate removal. Biological Processes Laboratory (LPB) São Carlos School of Engineering (EESC) University of São Paulo (USP), Av. João Dagnone, 1100, Santa Angelina Institute of Geosciences and Exact Sciences (IGCE) São Paulo State University (UNESP), Av. 24 A, 1515 - Bela Vista Environmental Microbiology Laboratory Institute of Science and Technology Federal University of Alfenas Rodovia José Aurélio Vilela, 11999 (BR 267 Km 533) Cidade Universitária Institute of Geosciences and Exact Sciences (IGCE) São Paulo State University (UNESP), Av. 24 A, 1515 - Bela Vista