## 3 Results and Discussion
### Removal of CR and MG by Activated Carbon and Dry Biomass of T. virens and T. viriide
However, linear correlation coefficients (R\({}^{2}\)) are higher for the Langmuir model than for the Freundlich model. Figure 5: Linear Freundlich (Equation (2)) and Langmuir (Equation (3)) adsorption isotherm for Congo red (row **A**) and malachite green (row **B**). For the Langmuir isotherm, the saturation capacity of the monolayer in the activated carbon (10.7) is greater than that for _T. virens_ (5.6) and _T. viride_ (2.76), for CR; whereas for the MG dye, _T. virens_ (81.8) had higher saturation capacity of the monolayer when compared to _T. viride_ and activated carbon. The constant \(K_{\rm L}\) for CR dye had similar values in all three adsorbent materials, whereas for MG, the \(K_{\rm L}\) was greater for activated carbon (Table 3). Reviewing the reports for the monolayer saturation capacity of other organic and inorganic adsorbents used for the removal of CR dye (Table 4), it was found that most of the materials showed a higher saturation capacity of the monolayer than that obtained for the two species of _Trichoderma_ reported in this study: straw carbon (403.7), grapefruit peel carbon (169.5), ground nut shells charcoal (117.6), bamboo dust carbon (101.9), Ca-bentonite (85.3), hen feather (73.8), and cassava residue (59.2), among others. Nevertheless, the saturation capacity was higher than that reported for other adsorbents such as laboratory-grade activated carbon and commercial-grade activated carbon, with 1.88 and 0.64, respectively [75; 76; 77]. On the other hand, for MG, few materials showed higher saturation capacity of the monolayer than _T. virens_ (Table 4): tobacco hairy roots (277.2), coco-peat (276.8), _Anethum graveelens_ (244.0), brown alga _Dictyota cervicornis_ (230.0), oil palm trunk fiber (149.4), and magnetic bacterial cellulose (270.3). Finally, it is worth noting the performance of the Ackee apple seed-bentonite composite, which showed the highest saturation capacity for both CR (1439.9) and MG (706.7). Thus, an alternative to improve the adsorption capacity of dry biomass of _T. virens_ is to apply an acid or alkaline pre-treatment or combine it with other materials or biomasses from other fungi or microorganisms. On the other hand, the kinetics studies reveal that adsorption rates of CR and MG by activated carbon and dry biomass of _T. virens_ and _T. viride_ are adequately described by the pseudo-second-order rate model (Figure 6). Table 5 shows the values obtained from the linear regression plots (\(t/q_{\rm t}\) vs. \(t\)) using the pseudo-second-order model, for the different concentrations of both dyes, finding that \(q_{\rm e}\) tends to increase along with \(C_{\rm e}\) in the three adsorbents tested in this study; the highest values of \(q_{\rm e}\) were obtained with activated carbon. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Dye**} & \multirow{2}{*}{**adsorbent**} & \multicolumn{2}{c}{**Freundlich**} & \multirow{2}{*}{**n**} & \multirow{2}{*}{**R\({}^{2}\)**} & \multicolumn{2}{c}{**Langmuir**} & \multirow{2}{*}{**K\({}_{\rm L}\) (L mg\({}^{-1}\))**} & \multirow{2}{*}{**R\({}^{2}\)**} & \multirow{2}{*}{**R\({}_{\rm L}\)**} \\  & & \(K_{\rm E}\) (**mg L\({}^{-1}\))\({}^{\text{1/2n}}\)** & & & & & \\ \hline CR & Activated carbon & 0.317 & 1.136 & 0.991 & 10.684 & 0.014 & 0.996 & 0.44 \\  & _T.virens_ & 0.102 & 1.270 & 0.990 & 5.577 & 0.012 & 0.995 & 0.48 \\  & _T. viride_ & 0.019 & 0.746 & 0.989 & 2.764 & 0.012 & 0.993 & 0.48 \\ MG & Activated carbon & 1.843 & 0.749 & 0.991 & 14.514 & 0.114 & 0.993 & 0.88 \\  & _T.virens_ & 0.348 & 1.027 & 0.991 & 81.818 & 0.002 & 0.994 & 0.84 \\  & _T. virile_ & 0.231 & 0.652 & 0.986 & 0.848 & 0.107 & 0.995 & 0.09 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: [PERSON] and [PERSON] adsorption isotherm parameters. Initial concentrations (\(C_{0}\)) of dye, 15 mg/L.