Using Hydrocotyle verticillata fermentation broth as a carbon source for sulfate-reducing bacteria to treat wastewater containing heavy metals

Abstract:

[Objective] We studied the use of Hydrocotyle verticillata fermentation broth as carbon source for sulfate-reducing bacteria and to remove heavy metals from wastewater. [Methods] Anaerobic sludge was used as the seed of sulfate-reducing bacteria, and reactors were fed with Hydrocotyle verticillata fermentation broth and synthetic wastewater containing Pb2+, Cd2+, Cu2+, Ni2+ and sulfate. [Results] Sulfate-reducing bacteria could use the organic matter in the fermentation broth, and the sulfate reduction rates were 24.4%, 43.6% and 60.0% when the ratios of COD to SO42– were 1.2, 5.0 and 7.0, respectively. When the concentrations of Cd2+, Cu2+, Pb2+ and Ni2+ were 10 mg/L, the removal rates of these heavy metals were more than 90%, and the activity of sulfate-reducing bacteria was not inhibited. [Conclusion] Hydrocotyle verticillata fermentation broth can be used as carbon source of sulfate-reducing bacteria to treat wastewater containing heavy metals.