2.6. Experiments

The two pilot-scale columns were followed for 6 months under continuous flow conditions. The liquid flow rate was maintained at 3 Ld−<sup>1</sup> . Woodwaste leachate percolated filters with a hydraulic load of 0.169 m3 m−<sup>2</sup> d−<sup>1</sup> . Air was applied upward at a flow rate of 5 m3 m−<sup>2</sup> h−<sup>1</sup> . Columns were fed with real woodwaste leachate, which presented a pH between 4.5 and 4.7 spiked to 1 μg mL−<sup>1</sup> with eight phenolic compounds and operated at room temperature (20–25°C). A flow sheet of the pilot scale unit is described in Figure 2.

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

The bacterial activity was inhibited in this column using mercuric chloride (HgCl2) at 0.5 g L<sup>−</sup><sup>1</sup> in the fed leachate. Only physicochemical retention by sorption and volatilization are in operation and responsible for phenolic compounds removal in this column. Liquid influent and effluent were sampled each day for 6 months to establish the parameters variation profiles. pH and COD were determined daily for the first 3 months and each 2 days from the 4th month. 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. Parameters profile variations are presented in Figures 4 and 5.

Figure 4. Physicochemical parameters variation in the effluent of column 1 (without bacterial activity).

Figure 5. Phenolic compounds profiles variation in the column 1 (without biological activity).

### 2.6.1.1. Media without biological activity characterization

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

Acclimation steps

1 2 345

V added (mL) 3 3 2 1 0

(% C) 100.00 96.63 90.54 76.13 0.00 ppm 0 2 4 6 8

V added (mL) 0 5 10 15 20 mg C 0 3.83 7.66 11.49 15.32 % (C) 0 3.37 9.46 23.87 100

AGV mg C 109.92 109.92 73.28 36.64 0.00

Phenol mg phenol 0 5 10 15 20

Total mg C 109.92 113.75 80.94 48.13 15.32

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.

The two pilot-scale columns were followed for 6 months under continuous flow conditions.

Columns were fed with real woodwaste leachate, which presented a pH between 4.5 and 4.7 spiked to 1 μg mL−<sup>1</sup> with eight phenolic compounds and operated at room temperature

The bacterial activity was inhibited in this column using mercuric chloride (HgCl2) at 0.5 g L<sup>−</sup><sup>1</sup> in the fed leachate. Only physicochemical retention by sorption and volatilization are in operation and responsible for phenolic compounds removal in this column. Liquid influent and effluent were sampled each day for 6 months to establish the parameters variation profiles. pH and COD were determined daily for the first 3 months and each 2 days from the 4th month. 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. Parameters profile

(20–25°C). A flow sheet of the pilot scale unit is described in Figure 2.

. Woodwaste leachate percolated filters with a

.

. Air was applied upward at a flow rate of 5 m3 m−<sup>2</sup> h−<sup>1</sup>

measurements during all the acclimation process.

378 Phenolic Compounds - Natural Sources, Importance and Applications

The liquid flow rate was maintained at 3 Ld−<sup>1</sup>

hydraulic load of 0.169 m3 m−<sup>2</sup> d−<sup>1</sup>

Table 2. Acclimation of biomass steps.

2.6.1. Pilot 1 (with mercuric chloride)

variations are presented in Figures 4 and 5.

2.6. Experiments

Both conventional scanning electron microscopy (SEM) and environmental scanning electron microscopy (ESEM) characterized media of pilot 1, with mercuric chloride. The environmental SEM offers all of the performance advantages of a conventional SEM, but allows high resolution and the analysis of wet and environmental samples in their current state without preliminary manipulations. Analysis was performed on JEOL 840-A (MEB) instrument for conventional SEM and on JSM-6360 instrument at low voltage (30 V of acceleration voltage) and with different vacuum values for ESEM.
