Mine Wastewater Treatment with Upflow Anaerobic Fixed Film Reactors

Microbial bioremediation of metals in wastewater by sulfate-reducing bacteria (SRB) has received much attention due to its high efficiency, eco-friendly techniques, and low cost. We investigated upflow anaerobic fixed film reactors (UAFFR) for removal of metals from artificial mine wastewater in the presence of two different carbon sources (lactate and ethanol), a range of temperatures, and pH. The UAFFR had different remediation reactors: R1 (inoculated directly with the sludge), R2 (inoculated with SRB-enriched culture), R3 (inoculated with SRB-enriched culture in combination with a pure culture of SRB species, i.e. Desulfotomaculum ruminis, to treat all of the metals together), and R4 (inoculated with an SRB-enriched culture in combination with the Desulfotomaculum ruminis, to treat individual metals). Of the four seeded reactors, those supplemented with SRB-enriched cultures (R2, R3, R4) removed the metals more efficiently than R1. The reactors using ethanol as the carbon source and polyhedral hollow balls removed sulfate and metals more efficiently than those with lactate and small pall rings.