Removal of nitrobenzene from aqueous solution by using modified magnetic diatomite

A novel magnetic diatomite was synthesized using a two-step method combining precipitation and combustion methods. The prepared magnetic diatomite with functional particles and strong magnetism was verified by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and vibrating sample magnetometer. Results showed that the modified magnetic diatomite performed better than the raw diatomite in the efficient removal of nitrobenzene from aqueous solution. The adsorption kinetics and the isothermal and desorption–adsorption properties were also studied. Results revealed that the adsorption kinetics and isothermal data corresponded to the pseudo-first-order kinetic model and chemisorption process. Desorption–adsorption experiments were conducted, and the as-prepared magnetic diatomite remained to have high nitrobenzene adsorption efficiency even after six cycles of desorption and adsorption. Furthermore, the synthesized magnetic diatomite can be quickly and easily separated using a magnet before and after adsorption.