Abstract: In order to solve the difficulty in separating powdery 4A zeolite from solution in application of 4A zeolite, a series of magnetic 4A zeolites with different Fe3O4 contents were synthesized by traditional hydrothermal method through ultrasonic crystallization for 6 h at 70 ℃ after adding magnetic Fe3O4 particulates to the crystallization solution for 4A zeolite synthesis. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), IR, magnetic susceptibility, TG/DTA, EDX and ion exchange capability. The results showed that the magnetic 4A zeolite had good magnetism and its magnetic susceptibility increased with the Fe3O4 amount increasing. For adsorption of F- and Cr (VI) in water, the adsorption capability of magnetic 4A zeolite is equal with the pure 4A zeolite and the adsorption rate filled well the pseudo-second-order rate model.

Key words: Ultrasonic, Magnetic 4A zeolite, Adsorption, Hydrothermal method