Gas-phase toluene biodegradation by Burkholderia vietnamiensis G4 in a biofilm membrane reactor

Abstract

[Abstract] A laboratory-scale biofilm membrane bioreactor inoculated with Burkholderia Vietnamiensis G4 was examined to treat toluene vapors from a synthetic waste gas stream. The gas feed side and nutrient solution were separated by a composite membrane consisting of a porous polyacrylonitrile (PAN) support layer coated with a very thin (0.3 µm) dense polydimethylsiloxane (PDMS) top layer. After inoculation, a biofilm developed on the dense layer. The biofilm membrane bioreactor was operated continuously at different residence times (28-5 sec) and loading rates (1.2-17.7 kg m-3 d-1), with an inlet toluene concentrations ranging from 0.21-4.1 g m-3. The overall performance of the membrane bioreactor was evaluated over a period of 151 days. Removal efficiencies ranging from 78-99% and elimination capacities ranging from 4.2-14.4 kg m-3 d-1 were observed depending on the mode of operations. A maximum elimination capacity of 14.4 kg m-3 d-1 was observed at a loading rate of 17.4 kg m-3 d-1. Overall, the results illustrate that biofilm membrane reactors can potentially be more effective than conventional biofilters and biotrickling filters for the treatment of air pollutants such as toluene