Thermophilic biofilter for SO2 removal: Performance and microbial characteristics

A bench-scale thermophilic biofilter was applied to remove SO2 at 60 degrees C in the present study. The SO2 concentration in the inlet stream ranged from 100 mg/m(3) to 200 mg/m(3). An average SO2 removal efficiency of 93.10% was achieved after developing acclimated organisms that can degrade SO2. The thermophilic biofilter effectively reduced SO2, with a maximum elimination capacity of 50.67 g/m(3)/h at a loading rate of 51.44 g/m(3)/h. Removal efficiency of the thermophilic biofilter was largely influenced by the water containing rate of the packing materials. The SO2 transfer in the biofilter included adsorption by the packing materials, dissolution in liquid, and microbial degradation. The main product of SO2 degradation was SO42-. The temporal shifts in the bacterial community that formed in the biofilter were determined through polymerase chain reaction-denaturing gradient gel electrophoresis and DNA sequence analysis. These shifts revealed a correlation between biofilter performance and bacterial community structure. (C) 2014 Elsevier Ltd. All rights reserved.