## 3 Results and Discussion  
### Removal of Organic Matter  
The evolution of sCOD concentration during the fungal treatments is shown in Figure 1.  
The initial sCOD value in the AL effluent was 4854 mg/L, which increased to 9243 mg/L after glucose addition. For C1 and C2 test, which were carried out without fungal inoculation, minor sCOD removals were observed. This degradation was carried out by the endogenous microbiota present in the effluent. With respect to test C1, no change was observed during the first two days and a 27% elimination of sCOD was achieved after four days of incubation. Afterwards, the sCOD value remained almost constant, reaching a final sCOD degradation of 30%. In the case of C2, where glucose where added, sCODdegradation did not occur until the 4 th day. The final percentage of sCOD removal was similar to that achieved with C1. However, it is necessary to point out that in C2 the final sCOD concentration was higher than the sCOD of AL before being supplemented with glucose. Therefore, the endogenous microorganisms were not able to assimilate even the sCOD provided by glucose added. The addition of _P. chrysosporium_ in E1 and E2, caused a fast decrease in sCOD from the beginning of the treatment, obtaining sCOD removals of 51% and 59%, respectively, after 10 days of treatment. In the experiment E1, carried out without the addition of glucose, 61% of the initial sCOD was degraded in only 4 days of treatment, which duplicate the degradation efficiency reached in C1 by endogenous microorganisms. Thus, the fungal inoculation gave an average rate of sCOD degradation of 0.51 mg/(L min) during the first 4 days, whereas the average rate in C1 was only 0.22 mg/(L min). Regarding test E2, again higher sCOD removals were obtained compared with the non-inoculated test C2. As in E1, the inoculation of the fungus duplicated the sCOD removal rate, which increased up to 0.61 mg/(L min) during first 8 days, whereas in C2 it was only of 0.27 mg/(L min). To estimate the fungus growth, the TSS at the beginning of the experiments and after 10 days were measured. Data are shown in Table 2.  
As can be seen, in the control tests (C1 and C2), the supplementation with glucose increased the growth of the endogenous microbiota. Moreover, in the inoculated tests (E1 and E2), the TSS increases were higher than in the controls, which can be explained by the fungus growth. Comparing the increase in TSS observed in controls and inoculated tests, it can be estimated that fungus growth was similar in E1 and E2, around 0.6-0.7 g/L (dry matter), which is in agreement with the fact that final sCOD removals were also similar. Therefore, in this case, the addition of glucose was not effective for the AL treatment. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample** & **Initial TSS (g/L)** & **Final TSS (g/L)** & **Increase (g/L)** \\ \hline C1 & 2.47 \(\pm\) 0.01 & 3.06 \(\pm\) 0.01 & 0.61 \(\pm\) 0.01 \\ E1 & 6.87 \(\pm\) 0.01 & 8.21 \(\pm\) 0.01 & 1.34 \(\pm\) 0.01 \\ C2 & 2.47 \(\pm\) 0.01 & 5.16 \(\pm\) 0.01 & 2.71 \(\pm\) 0.01 \\ E2 & 6.87 \(\pm\) 0.02 & 10.16 \(\pm\) 0.02 & 3.29 \(\pm\) 0.02 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: TSS for control (C1 and C2) and inoculated (E1 and E2) tests at initial and final times of the fungal treatment. Figure 1: Changes in sCOD concentration during biological treatment. The dashed lines shown the non-inoculated tests C1 () and C2 (), used as controls. The solid lines shown the inoculated tests E1 () and E2 (). The standard deviation (SD) of the experimental data were in all cases less than 6.5% of mean value. Results for sCOD removals here obtained were higher than have been previously reported. [PERSON] et al. [33], reported that a 44% of COD removal was achieved by a solid-state fermentation of AL using _P. chrysosporium_ in a support of sugarcane bagasse. [PERSON] et al. [26] achieved a COD degradation around 50% using this fungus immobilized on loofah. [PERSON] et al. [34] reported COD removals efficiencies lower than 44% for _P.