Adsorption of Congo red with hydrothermal treated shiitake mushroom

The shiitake mushroom was treated by hydrothermal method to obtain a novel biosorbent. Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy and Brunauer–Emmett–Teller (BET) method have been used to characterize the physico-chemical properties of the novel biosorbent. Factors affecting the adsorption properties of Congo red onto biosorbent such as pH, dose, time and temperature were investigated respectively. The experimental data more suitable for the langmuir model than the Freundlich model. The maximum adsorption capacity of the biosorbent obtained by the Langmuir model at 293 K was 217.86 mg g⁻¹. The kinetic study illustrated that the adsorption fit the pseudo-first-order model. Thermodynamic analysis indicated that the adsorption reaction was a spontaneous endothermic reaction. (paper)