2.6.2.1. Biomass characterization

MicrobialaspectsoffixedbiofilmatdifferentbiofilterlayerswereshownbybothconventionalSEM andESEMimagingperformedon JEOL840-A (MEB) and JSM-6360instruments, respectively.

Biological characterization of bacterial diversity in the mixed biofilm was performed by DGGE of the 16 S ribosomal RNA genes molecular technique. PCR-DGGE is a rapid and sensitive method for the detection and investigation of active species in fixed media based on the DNA fragments extraction. Amplicons, with the same length, of dominant microbial organisms are separated in gradient gel based on their differential denaturation process and nucleotide compositions. Two samples were collected by coring the media, during and at the end of experiments. The first coring was done in the middle of the column. The second coring extraction was realized at eight different level heights of the biofilter. Gel preparation and analysis were carried out according to the protocol established by Ercolini [26] and run at Dr Duchaine's research laboratory at Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de l' Hôpital Laval (Québec, Canada).

### 2.6.3. Pilot 1 (with mercuric chloride)

The two laboratory-scale columns were set-up and followed for 4 months under continuous flow conditions. Real woodwaste leachate at pH of 4.5–4.7 and spiked with 1 μg mL−<sup>1</sup> of eight phenolic compounds was percolated under the same conditions applied to the pilot unit: hydraulic loading of 0.169 m<sup>3</sup> m−<sup>2</sup> d−<sup>1</sup> and flow rate aeration of 5 m3 m−<sup>2</sup> h−<sup>1</sup> . These laboratory units were followed to reproduce the top of pilot-scale columns and to describe the phenolic compounds removal at the top of these columns. A flow sheet of this mini-columns setup is described in Figure 3.

### 2.7. Parameters analysis

Analyses of phenolic compounds were performed on a Breeze HPLC system (Waters ©) consisting of a 717 plus auto sampler, a 1525 binary pump with internal degasser, and a code

Figure 6. SEM and ESEM imaging of media of pilot 1 (with mercuric chloride).

SEM and on JSM-6360 instrument at low voltage (30 V of acceleration voltage) and with different

This pilot simulates the real behavior of a trickling biofilter. The mechanisms of biodegradation, sorption, and volatilization are to be present and in operation during biofiltration. For this column also, phenolic compounds were quantified each 2 days in the liquid influent and effluent and twice a week in the collected steam during all the operation period. The parameters that were monitored in the liquid influent and effluent were BOD, COD, pH, Nitrogen, and phenolic compounds and measured once a week for BOD, and each 2 days for all the other parameters during all the operation period. VFAs were determined sporadically. Parameters

MicrobialaspectsoffixedbiofilmatdifferentbiofilterlayerswereshownbybothconventionalSEM andESEMimagingperformedon JEOL840-A (MEB) and JSM-6360instruments, respectively.

Biological characterization of bacterial diversity in the mixed biofilm was performed by DGGE of the 16 S ribosomal RNA genes molecular technique. PCR-DGGE is a rapid and sensitive method for the detection and investigation of active species in fixed media based on the DNA fragments extraction. Amplicons, with the same length, of dominant microbial organisms are separated in gradient gel based on their differential denaturation process and nucleotide compositions. Two samples were collected by coring the media, during and at the end of experiments. The first coring was done in the middle of the column. The second coring extraction was realized at eight different level heights of the biofilter. Gel preparation and analysis were carried out according to the protocol established by Ercolini [26] and run at Dr Duchaine's research laboratory at Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de l' Hôpital Laval

The two laboratory-scale columns were set-up and followed for 4 months under continuous flow conditions. Real woodwaste leachate at pH of 4.5–4.7 and spiked with 1 μg mL−<sup>1</sup> of eight phenolic compounds was percolated under the same conditions applied to the pilot unit:

units were followed to reproduce the top of pilot-scale columns and to describe the phenolic compounds removal at the top of these columns. A flow sheet of this mini-columns setup is

Analyses of phenolic compounds were performed on a Breeze HPLC system (Waters ©) consisting of a 717 plus auto sampler, a 1525 binary pump with internal degasser, and a code

. These laboratory

hydraulic loading of 0.169 m<sup>3</sup> m−<sup>2</sup> d−<sup>1</sup> and flow rate aeration of 5 m3 m−<sup>2</sup> h−<sup>1</sup>

profile variations for the biofilter are presented in Figures 6 and 7.

vacuum values for ESEM.

2.6.2. Pilot 1 (with mercuric chloride)

380 Phenolic Compounds - Natural Sources, Importance and Applications

2.6.2.1. Biomass characterization

(Québec, Canada).

described in Figure 3.

2.7. Parameters analysis

2.6.3. Pilot 1 (with mercuric chloride)

Figure 7. Physicochemical and biological parameters variation in the effluent of column 2 (biofilter).

model 5CH column oven. The separation was carried out on a Symmetry C18 (4.6 × 150 mm, 5 μm) column and detection by a 2487 dual wavelength detector. Samples were previously acidified to pH between 1.8 and 2, filtered on 0.45 μm membrane filter, concentrated by SPE on Oasis HLB (60 mg) cartridges and then analyzed by liquid chromatography according to the method described by Kamal et al. [27].

COD and nitrogen were determined according to standard methods using a DR3000 spectrophotometer. BOD was measured using a standard BOD Track system and a polyseed as bacterial consortium.
