A comparative assessment of biofiltration and activated sludge diffusion for odour abatement

The deodorization performance of a biofilter and an activated sludge diffusion (AS) system was comparatively evaluated in terms of removal efficiency (RE) and process stability at empty bed residence times (EBRT) ranging from 94 to 32 s. Both bioreactors were fed with a synthetic odorous emission containing H2S. butanone and toluene at 23.6-43.3, 4.3-6.3 and 0.4-0.6 mg m(-3), respectively. While the outlet H2S concentration was always lower than 1.4 mg m(-3), the REs for butanone and toluene remained higher than 95% in both bioreactors regardless of the EBRT. The continuous supply of wastewater in the AS unit did not affect removal and appeared to be a requirement for efficient pollutant abatement. Despite the narrow carbon source spectrum treated, the AS system maintained a large bacterial diversity over time. Therefore, the results obtained confirmed the potential of AS systems as a robust and efficient biotechnology for odour treatment in WWTPs. (C) 2011 Elsevier B.V. All rights reserved.