## Results and Discussion
### Biotreatment of Support Materials  
After 7 days of bioreactor operation, the support materials with hydrocarbons absorbed were considered as waste materials; they were removed from the bioreactors and deposited in sterile containers at controlled temperature (28 \({}^{\circ}\)C), to determine hydrocarbon degradations after 7 days, 1 and 4 and 8 months of incubation. The results of this carrier biotereatment phase showed that microbial populations were able to remain steady or grow during the assays. For Pad Sentectm, the adhering microbial population was 5.5-6.5 Log (UFC mL\({}^{-1}\)) during the assays and at around 7.5 Log (UFC mL\({}^{-1}\)) for CorkSorbtm 01025. Microbial populations adhered to Barrier Sentectm proliferated throughout the assay to reach 8.1 Log (UFC mL\({}^{-1}\)) at the end of the carrier biotereatment process (Figure 3). These results indicate that microorganisms that adhered to the three different carriers become a stable biofilm characterized by hydrocarbon tolerance. [PERSON] et al. [31] and [PERSON] and [PERSON] [32] reported that cork was a suitable material as a carrier for inocula. This has also been demonstrated by [PERSON] and [PERSON] [33], who verified the red wine spoilage sealed with natural cork closures by acetic acid bacteria. Several authors have also pointed out that meltblown polypropylene carriers are good candidates for bacterial adherence material [34; 35; 36]. Moreover, similar results to those of our study have been reported by several authors [37; 38], who observed the development of stable biofilms in different support materials and verified their applicability to the treatment of wastewater polluted by hydrocarbons. Consequently, our results are in agreement with previous publications and suggest the biodegradable capacity of the biofilms detected in our study. With regard to the removal of hydrocarbons absorbed by the Pad Sentectm carrier during wastewater treatment, it was observed that an important reduction of the TPH concentrations during the 8 months of incubation in the support material was evident, however, the amount of TPH in the CorkSorbtm 01025 and Barrier Sentectm support materials were not reduced during the experiments (Figure 4). Figure 3: Indigenous microbiota adhered to Pad Sentectm, CorkSorbtm 01025 and Barrier Sentectm carriers during the carrier biotereatment phase, expressed as log(UFC/g carrier). (*) Significant differences between Corksorbtm 01025 and the other carriers; (*) Significant differences between Pad Sentectm and Corksorbtm 01025; (*) Significant differences between Pad Sentectm, Corksorbtm 01025 and Barrier Sentectm. Oil products are a complex mixture of hydrocarbons with different susceptibility to being degraded by microorganisms, for example, n-alkanes are more biodegradable than branched alkanes or polycyclic aromatics compounds. Consequently, the study of the changes in the concentrations of hydrocarbon fractions through a period of biote treatments can give information about the efficiency of the bioremediation treatment with regard to the completion of hydrocarbon removal. Figure 5A-C shows the hydrocarbon removal during the first month of biote treatments of Pad Sentec(tm), Barrier Sentec(tm) and CorkSorb(tm) 01025 carriers. In Pad Sentec(tm) microcosms, the GC/MS analyses demonstrated that after one month of incubation of the support materials in sterile containers, the majority of the hydrocarbon fractions were almost completely removed, except for phytane and pristine. Figure 5A shows that during the first month of carrier treatment, alkanes C\({}_{10}\)-C\({}_{20}\) were almost totally degraded. This fraction has been considered by some authors as the most easily biodegradable fraction [23; 39; 40; 41] and can, therefore, be used as an accurate indicator of hydrocarbon degradation. In the same way, the increase of both branched hydrocarbons, phytane and pristane, is generally related to the biological hydrocarbon degradation.