3.3.1. Phenolic compounds profiles variation in the biofilter

Phenolic compounds profile variation, presented in Figure 8, followed absolutely COD and BOD variations in the biofilter. Indeed, a significant decrease was observed in the effluent during the first 10 days of operation and performance removal of 99.9% was obtained at steady state for all the phenolic compounds. A maximum of 5–7% of volatilization was observed for phenol and chlorophenol in the biofilter.

Figure 8. Phenolic compounds profiles variation in the column 2 (biofilter).

### 3.3.2. Biomass acclimation results

Table 2 shows the detailed steps for acclimation process. Activated sludge from the sewage treatment station Valcartier in Québec City area was used as a source of microorganisms for biomass acclimation. Volatile fatty acids (VFAs) and phenol were used as the carbon source for microorganisms.

### 3.3.3. Biomass characterization results

Both conventional SEM and ESEM imaging showed microbial aspects of fixed biofilm at different biofilter layers. SEM and ESEM images are given in Figure 9.

A sampling at different column heights was done, by coring of the biofilter in the last week of operation period. Figure 10 shows the column sampling. Media samples were analyzed by DGGE technique with gel sequence and sequences amplified to determine the composition of the bacterial community. Samples 7 and 8 represent the 10 cm perlite layer at the top of the biofilter. Results of DGGE banding patterns of 16S rDNA fragments presented by Figure 11 show the presence of generally similar bacterial species. Two intense bands present in perlite layer disappeared in the depth of biofilter to be replaced by other bands. This may be explained by the development of other microorganisms in the media mixture of peat and perlite. The bands representing the different heights of the mixed media are in general similar; this indicates that the same active species are present in all the peat/perlite mixture height of the biofilter and are involved in the phenolic compounds biodegradation process. The list of

3.3.2. Biomass acclimation results

3.3.3. Biomass characterization results

microorganisms.

Table 2 shows the detailed steps for acclimation process. Activated sludge from the sewage treatment station Valcartier in Québec City area was used as a source of microorganisms for biomass acclimation. Volatile fatty acids (VFAs) and phenol were used as the carbon source for

Both conventional SEM and ESEM imaging showed microbial aspects of fixed biofilm at

A sampling at different column heights was done, by coring of the biofilter in the last week of operation period. Figure 10 shows the column sampling. Media samples were analyzed by DGGE technique with gel sequence and sequences amplified to determine the composition of the bacterial community. Samples 7 and 8 represent the 10 cm perlite layer at the top of the biofilter. Results of DGGE banding patterns of 16S rDNA fragments presented by Figure 11 show the presence of generally similar bacterial species. Two intense bands present in perlite layer disappeared in the depth of biofilter to be replaced by other bands. This may be explained by the development of other microorganisms in the media mixture of peat and perlite. The bands representing the different heights of the mixed media are in general similar; this indicates that the same active species are present in all the peat/perlite mixture height of the biofilter and are involved in the phenolic compounds biodegradation process. The list of

different biofilter layers. SEM and ESEM images are given in Figure 9.

Figure 8. Phenolic compounds profiles variation in the column 2 (biofilter).

384 Phenolic Compounds - Natural Sources, Importance and Applications

Figure 9. SEM and ESEM imaging of microbial aspects of fixed biofilm at different biofilter layers.

Figure 10. Media samples from different heights of the biofilter.

Figure 11. Gel sequence and DGGE banding results of active spices in different biofilter levels. Names of referred bacteria are listed in Table 3.

most abundant active species is given in Table 3. Both heterotrophic and autotrophic bacterial species are present in the biofilter with a predominance of heterotrophic population.


Table 3. Most abundant active species and results of PCR re-amplified and sequenced 16S rDNA DGGE bands.
