• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.7
• /
• pp.770-775
• /
• 2006

Biofilters packed with various materials commonly show problems such as low performance and clogging in a long-term operation. Recently, a bioactive foam reactor(BFR) using surfactants has been suggested to ensure efficient and stable VOCs removal performance. This study was mainly conducted to investigate the feasibility of the BFR system using styrene as a model compound. An abiotic md a biotic tests were conducted to estimate a mass transfer coefficient($K_La$) and a specific substrate utilization coefficient(k) for the BFR, showing the rate of mass transfer was greater in the BFR than in other diffuser systems. A dynamic loading test also indicated that the performance of the BFR was stable under a shock loading condition. Furthermore, the maximum elimination capacity of the BFR was determined to be 109 $g/m^3/hr$ for styrene, which was much higher than those for biofilter systems generally reported in the literature. Overall, the experimental results suggest that the BFR be a potential alternative to the conventional packed-bed biofilters.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.6B
• /
• pp.689-694
• /
• 2006

The system performance of a bioactive foam reactor (BFR), that consists of a foam column using a surfactant and a biodegradation basin containing suspended bacteria, was investigated for the treatment of gaseous toluene or a mixture of four volatile organic compounds (VOCs, benzene, toluene, p-xylene, and styrene). Overall, the BFR achieved stable VOC removal efficiencies, indicating that it can be used as a potential alternative over conventional packed-bed biofilters. Furthermore, a dynamic loading test showed that relatively constant removal was maintained at the elevated loading due to a high mass transfer rate in the foam column. However, as the inlet concentration of VOCs increased, a portion of the VOCs mass-transferred to the liquid phase was stripped out from the biodegradation basin, resulting in a decrease in the overall removal efficiency. In the BFR, the removal efficiency of the individual VOC was mainly determined depending on the biodegradation rate (styrene > toluene > benzene > p-xylene), rather than the mass transfer rate. Consequently, increases in the microbial activity and the volume of the basin could improve the overall performance of the BFR system. Further investigation on microbial activity and community dynamics is required for the BFR when subjected to high loadings of VOC mixtures.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.5
• /
• pp.468-475
• /
• 2005

Biofilters packed with various materials have emerged as a sustainable technology for the treatment of volatile organic compounds (VOCs); however, problems including low performance and clogging are commonly encountered. Recently, a bioactive foam reactor (BFR) using surfactants has been suggested to ensure efficient and stable VOCs removal performance. This study was mainly conducted to investigate the feasibility of BFRs using toluene as a model compound. Prior to bioreactor studies, a series of bottle tests were used to select a suitable surfactant for the BFR application. Experimental results of the batch bottle tests indicated that TritonX-100 was the most appropriate one among the surfactants tested, since it showed a minimal effect on the toluene biodegradation rate while the other surfactants lowered the toluene biodegradation rate significantly. Using the selected surfactant, the BFR performance was determined by changing operating parameters including gas residence time and toluene loading. As the gas residence time increased from 0.5 minutes to 2 minutes, the toluene removal efficiency increased from approximately 50% to 80%. In addition, an increase of the toluene loading from $38\;g/m^3/hr$ to $454\;g/m^3/hr$ resulted in a decrease of toluene removal efficiency from approximately 70% to 20%. The BFR had a maximum elimination capacity of $108\;g/m^3/hr$ for toluene, which was much higher than those generally reported in the literature. The high toluene-elimination performance indicates that the BFR be a potential alternative to the conventional, packed-type biofilters. However, the limitation of toluene solubilization and foam stability at either high or low gas flow rate are still problems to be challenged.