3.3. Pilot 2 (biofilter) results

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

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

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

Table 1 shows the real leachate physicochemical characterization and phenolic compounds quantification from winter of 2006 to summer of 2009. Phenols were found at concentrations varying between 0.38 μg mL−<sup>1</sup> for phenol and 1.1 μg mL−<sup>1</sup> for 2,4-dinitrophenol in real

COD drastic decrease was observed in the effluent during the first 10 days of operation. Note that 84.41% of initial COD was removed during this operation period. From the second week,

method described by Kamal et al. [27].

382 Phenolic Compounds - Natural Sources, Importance and Applications

bacterial consortium.

3. Results and discussion

3.1. Woodwaste leachate characteristics

woodwaste leachate on winter of 2006.

3.2. Pilot 1 (with mercuric chloride) results

A significant decrease was observed in the effluent during the first 10 days of operation for both COD and BOD. These parameters increased during the second and third week. This can be explained by a resistance and often observed inhibitory effect of organisms during the acclimation process. Good performances of the biofilter were obtained after 30 days. On the 47th day, the system received a high organic load and toxicity due to a periodic increase at the sawmill providing the effluent. However, the biofilter was able to manage this organic shock and fluctuations and to achieve excellent performances at steady state. Indeed, 97–98.2% of COD and BOD removal were observed, respectively. Another increase of the measured parameters was observed on the 135th operation day. This can be explained by the saturation of the media and biological phenomena become a predominant and responsible factor for the treatment. The system, in this situation also, was able to manage the change of physicochemical retention capacities of the media and to achieve the performances of the previous steady state in few days. Figure 7 shows 59 and 22 mg L−<sup>1</sup> values for COD and BOD, respectively, with superior performances in reducing organics (97% COD and (98.2% BOD reduction)).
