Removal of anionic dye using amine-functionalized mesoporous hollow shells prepared from corn cob silica

This study evaluated the performance of amine-functionalized mesoporous hollow spheres obtained using corn cob (an agriculture byproduct) nanosilica as support material for amine immobilization (NH2-MHS) for removal of Congo Red (CR) dye from aqueous solution. Physical characteristics of adsorbents were studied using zeta potential, N-2 adsorption-desorption isotherms, surface area, high-resolution transmission electron microscopy, Fourier-transform infrared spectroscopy, and field-emission scanning electron microscopy. The effects of various physiochemical parameters such as pH (3-9), different adsorbents, temperature (15, 25, and 35 A degrees C), initial dye concentration (10-500 mg/L), and adsorbent dosage (0.1-1.0 g) on the CR removal efficiency were investigated. The equilibrium adsorption data were well fit by the Freundlich model. The maximum adsorption capacity of CR onto NH2-MHS according to the Langmuir isotherm model was 98.72 mg/g at 35 A degrees C and pH 7. The adsorption kinetics were well fit using a pseudo-second-order kinetic model.