2.4. Leachate

Woodwaste leachate was collected from a sawmill site in the Quebec City area and characterized. This effluent is a complex matrix with highly variable chemical composition. Concentrations of phenolic compounds depend on the temperature, age, and industrial activities of the region, in particular, those of sawmills and paper industries. Physicochemical characteristics are given in Table 1.

### 2.5. Biomass acclimation

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. The acclimation was conducted progressively to avoid shock to the microorganisms due to the toxicity and to allow the biomass growth. At first, only VFAs were used as carbon source and were replaced gradually by phenol. Table 2 shows the detailed composition for acclimation process. A synthetic mixture Phenolic Compounds Removal in Woodwaste Leachate by a Trickling Biofilter http://dx.doi.org/10.5772/66755 377

refrigerators set to 4°C and aeration system connected to compressed air source with copper tubes in T-shape and connected to the bottom of each column using rigid tubes after passing in control air flow rate system. Columns are also equipped with exit air steam collector composed of four bottles containing each 100 ml of methanol, connected in series for each column via T-shape connection with the out vacuum evacuation. The output air steam was collected for 4 hours twice a week and if the air steam collection was not in operation, the valve connected to the out vacuum evacuation was opened. Woodwaste leachate was fed continuously to columns via Masterflex tubes at the top using a peristaltic pump, simulating trickling filtration.

Columns were packed with solid support consisted of a mixture of peat (70% with 0.5 mm) and perlite (4–6 mm) at a 1:9 ratio. After characterization, the peat was dried at 103°C during 48 h to minimize bacterial activity. A layer of coarse gravel with 0.10 m of height was installed first at the bottom of the two columns and then these were packed with the media at a layer height of 1.30 m as described in Figure 1. A layer of perlite with 0.10 m of height was installed at the top of the two columns. For the conditioning, columns were fed slowly with tap water (1.5–2 h) in an ascending way to reach a maximum absorption capacity of water by peat [25], a good consistency of media and a resistance to compaction. The conditioning of columns

Two mini-columns with 0.12 m of diameter and 0.20 m of height were set up as described in Figure 3 to simulate the top of pilot columns and to follow efficiency and parameters variabil-

Woodwaste leachate was collected from a sawmill site in the Quebec City area and characterized. This effluent is a complex matrix with highly variable chemical composition. Concentrations of phenolic compounds depend on the temperature, age, and industrial activities of the region, in particular, those of sawmills and paper industries. Physicochemical characteristics

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. The acclimation was conducted progressively to avoid shock to the microorganisms due to the toxicity and to allow the biomass growth. At first, only VFAs were used as carbon source and were replaced gradually by phenol. Table 2 shows the detailed composition for acclimation process. A synthetic mixture

2.2. Media composition and preparation

376 Phenolic Compounds - Natural Sources, Importance and Applications

removes also the retained air in the system.

ity with time at the top of the pilot scale units.

2.3. Laboratory scale unit set up

2.4. Leachate

are given in Table 1.

2.5. Biomass acclimation

Figure 3. Laboratory scale unit simulating the top of pilot columns to follow phenolic compounds removal.


Note: Total phenolic compounds were determined by spectrophotometric analysis. Individual phenolic compound values reported in μg L−<sup>1</sup> .

Table 1. Physicochemical characterization and phenolic compounds quantification of woodwaste leachate.


VFAs: 80 g L−<sup>1</sup> (36.64 g-C/L); phenol: 1 g L−<sup>1</sup> (0.766 g-C/L); nutrients: 65.86 g L−<sup>1</sup> (0.052 g-N/L); volume of reactor: 2.5 L.

Table 2. Acclimation of biomass steps.

of the eight studied phenolic compounds was given as substrate when the biomass was acclimated and then the real woodwaste leachate was used for the biomass growth before use in the biofilter. The biomass growth and substrates utilization were followed by respirometric measurements during all the acclimation process.
