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2961837 
Journal Article 
COMPARISON OF UASB AND FLUIDIZED-BED REACTORS FOR SULFATE REDUCTION 
Bertolino, SM; Silva, LAM; Aquino, SF; Leao, VA 
2015 
1 
Brazilian Journal of Chemical Engineering
ISSN: 0104-6632
EISSN: 1678-4383 
32 
1 
59-71 
WOS:000354788300007 
Reactor hydrodynamics is important for sulfidogenesis because sulfate reduction bacteria (SRB) do not granulate easily. In this work, the sulfate reduction performance of two continuous anaerobic bioreactors was investigated: (i) an upflow anaerobic sludge blanket (UASB) reactor and (ii) a fluidized bed reactor (FBR). Organic loading, sulfate reduction, and COD removal were the main parameters monitored during lactate and glycerol degradation. The UASB reactor with biomass recirculation showed a specific sulfate reduction rate of 0.089 +/- 0.014 g.gSSV(-1).d(-1) (89% reduction), whereas values twice as high were achieved in the FBR treating either lactate (0.200 +/- 0.017 g.gSSV(-1).d(-1)) or glycerol (0.178 +/- 0.010 g.gSSV(-1).d(-1)). Sulfate reduction with pure glycerol produced a smaller residual COD (1700 mg.L-1) than that produced with lactate (2500 mg.L-1) at the same COD. sulfate(-1) mass ratio. It was estimated that 50% of glycerol degradation was due to sulfate reduction and 50% to fermentation, which was supported by the presence of butyrate in the FBR effluent. The UASB reactor was unable to produce effluents with sulfate concentrations below 250 mg.L-1 due to poor mixing conditions, whereas the FBR consistently ensured residual sulfate concentrations below such a value. 
Sulfate reduction; Anaerobic processes; Fluidized bed bioreactors; Glycerol; Upflow anaerobic sludge blanket; Wastewater treatment