Congo red removal from aqueous solution via biosorption onto Trametes trogii‐loaded poly(hydroxyethyl methacrylate) cryogel

In this study, Trametes trogii‐loaded poly(2‐ hydroxyethyl methacrylate) cryogel (Tt‐PHEMA) was prepared and used as a biosorbent to remove Congo Red (CR), from aqueous solutions. The biomass and Tt‐PHEMA cryogel were characterized with scanning electron microscopy and Fourier Transform infrared spectroscopy. Macroporosity degree (%) and swelling ratio (%) of the Tt‐PHEMA cryogel were determined as 78.3% and 61.04%, respectively. The effect of loaded biomass amount, pH, initial CR concentration, temperature, and contact time were investigated detailedly. The maximum biosorption capacity of Tt‐PHEMA cryogel was 156.71 ± 1.22 mg g−1 at pH 6.0 at 45°C. Biosorption capacity was increased from 125.92 ± 1.524 mg g−1 to 156.71 ± 1.22 mg g−1 with increasing temperature from 25 to 45°C, demonstrating that the biosorption process was endothermic. The biosorption data were well fitted to the Freundlich isotherm and pseudo‐second‐order kinetic models. The negative Gibbs free energy change values showed favorable biosorption. The Tt‐PHEMA cryogel was easily regenerated with ethanol and used repeatedly five times without a significant change in the biosorption capacity. As a result, Trametes trogii‐loaded PHEMA cryogel has an application potential for CR removal from wastewater, taking advantage of interconnected macroporous structure cryogels.