Preparation of a novel magnetic geopolymer/zero-valent iron composite with remarkable adsorption performance towards aqueous Acid Red 97

摘要

A magnetic geopolymer was prepared from the silica and metakaolin under presence of zero-valent iron (ZVI). The magnetic geopolymer was characterized by Fourier-Transform Infrared spectroscopy, X-ray diffraction, N-2 adsorption/desorption isotherms, scanning electron microscopy, and vibrating sample magnetometer. The geopolymer was employed as adsorbent of Acid Red 97 dye. The results showed that the magnetic geopolymer have mesoporous structure and sufficient magnetization to be removed by a magnetic field from aqueous solution. Both the pseudo-first and pseudo-second order models satisfactorily described the adsorption kinetics, and the isotherms were properly adjusted by the Henry's model. High adsorptive capacity of dye (1814 mg g(-1)) was obtained, and the geopolymer can be used for five times with the same initial adsorption capacity. An efficient adsorbent was developed from low cost materials. This adsorbent presented extremely high adsorption capacity and can be easily separated from the treated liquid effluent.