Biofiltration of waste gases containing both ethyl acetate and toluene using different combinations of bacterial cultures

To investigate the microbial degradation of ethyl acetate and toluene mixtures in biofiltration, three strains were selected, identified and studied in a shake-flask culture, and finally inoculated into biofilters. These strains, namely AC6, TO3 and B5, can degrade different substrates at a different rate. The results showed that competitive inhibition from substrate and microbial community would affect the toluene degradation efficiency. Owing to substrate competition, the toluene degradation efficiency of strain B5 would decrease in the presence of high concentration of ethyl acetate. However, the addition of strain AC6 would alleviate such inhibition because it could remove ethyl acetate rapidly. Microbial community competition from strain AC6 or 135 would impede the toluene degradation efficiency of strain TO3 unless a large amount of strain TO3 was inoculated. In biofiltration, strain B5 would be a better choice for inoculation into biofilters than strains AC6 and TO3, as it would grow rapidly under a low concentration of ethyl acetate. (C) 2003 Elsevier B.V. All rights reserved.