Treatment of Volatile Organic Compounds in a Biotrickling Filter under Thermophilic Conditions

Abstract

The objectives of this research were to investigate the potential to biologically treat volatile organic compounds emitted by the forest products industry at thermophilic conditions and to examine the microbial community developed at high temperatures. Three biotrickling filters were run in parallel at temperatures ranging from 40 degrees C (mesophilic control) to 70 degrees C. The first phase involved treatment of methanol, for a 3-month run, and the second phase involved a 260-day run on the treatment of alpha-pinene. Methanol removal rates over 100 g m(-3) h(-1) where achieved at temperatures up to 70 degrees C. Alpha-pinene removal was achieved at temperatures up to 60 degrees C with optimal treatment occurring at 55 degrees C at rates up to 60 g m(-3) h(-1). The time for acclimation increased with increasing temperature and was longer for pinene than for methanol. Filter performance was also able to quickly recover from a shutdown period of up to 2 weeks due to the robustness of the microbial communities as determined by DNA fingerprinting analysis. The high-temperature communities treating methanol or pinene were more similar to each other than the mesophilic communities (i.e., 40 degrees C). The mesophilic methanol community had a high degree of functional redundancy, while the mesophilic pinene community was more unique and very distinct from the others. These results show that biofiltration at high temperatures is achievable and opens up a range of possibilities for applying biofiltration to hot gas streams.

Effect of Nutrient Periodicity on Microbial Community Dynamics

“…Thus, although different phylotypes arose in different replicates, their performances in these systems were similar enough to result in communities whose functions were indistinguishable from each other. This implies a substantial degree of functional redundancy in these microbial communities, as has been found in a variety of natural and engineered microbial ecosystems (2,10,22,38,45). One rationale for the emphasis on analysis of microbial community composition in microbial ecology has been that determining composition is key to understanding community functionality.…”

Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics

“…Elimination capacity can be increased using thermophilic bacteria instead of mesophilic bacteria. Furthermore, thermophilic bioreactors exhibit low biomass accumulation, thus alleviating the risk of clogging (Kong et al 2001;Mohammad et al 2007). Sulfur dioxide and other sulfur compounds have been successfully purified through thermophilic biofiltration (Morales et al 2012;Zhang et al 2015).…”

Temporal variation of microbial population in a thermophilic biofilter for SO 2 removal

“…When the temperature in the biofilter was less than 25°C or over 50°C, a marked decrease occurred in the hydrogen sulfide (H 2 S) removal efficiency, which was caused by a decline in sulfur oxidation bacteria (Yang and Allen, 1994). The application of thermophilic microorganisms for the treatment of off-gas at over 50°C would increase elimination rates and the desired efficiency would be achieved at shorter reaction times or a smaller reactor volume (Kong et al, 2001). Another advantage of thermophilic operation is a decrease in the biomass yield and its accumulation in the biofilter bed, which normally causes bed clogging and pressure drop through the bed.…”