The present study evaluated the removal efficiency of two dyes, Congo red (CR) and malachite green (MG), using either fresh or dry fungal biomass of two species of Trichoderma (T. virens and T. viride) and activated carbon. After 24 h, the CR removal efficiency obtained with fresh biomass was higher than that obtained with activated carbon. For the MG dye, the average removal with activated carbon (99%) was higher than those obtained with dry and fresh biomass of T. viride and T. virens. Experimental results for fresh and dry fungal biomass showed a good correlation with Langmuir isotherms. The adsorption rates of CR and MG by of T. virens and T. viride can be more appropriately described using the pseudo-second-order rate. We found an adsorption capacity of 81.82 mg g⁻¹ for T. virens with MG dye. Results show that fresh or dry biomass of T. virens can represent a simple and cost-effective alternative for removing industrial dyes such as CR and MG.

Polymeric membranes of poly(ethylene oxide) (PEO) and sodium trifluoroacetate (PEO:CF₃COONa) combined with different concentrations of aluminum oxide (Al₂O₃) particles were analyzed by impedance spectroscopy, differential scanning calorimetry (DSC) and thermogravimetry (TGA). DSC results show changes in the crystalline fraction of PEO when the concentration of Al₂O₃ is increased. TGA analysis showed thermal stability up to 430 K showing small changes with the addition of alumina particles. The decrease in crystalline fraction for membranes with low Al₂O₃ concentration is associated with the increase in conductivity of (PEO)₁₀CF₃COONa + x wt.% Al₂O₃ composites.