Preparation of FeOOH nanoparticles using an impinging stream-rotating packed bed and their catalytic activity for ozonation of nitrobenzene

Abstract

BackgroundFeOOH has the advantages of low price, high stability and high surface hydroxyl content that make it an excellent catalyst for wastewater treatment. However, it also has the problems of wide particle size distribution, non-uniform dispersion and long preparation time in traditional reactors. MethodsFeOOH nanoparticles were prepared from FeSO4 and NaOH in an impinging stream-rotating packed bed (IS-RPB-FeOOH), and their properties and catalytic activities were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Significant findingsThe prepared FeOOH nanoparticles are shown to be α-FeOOH with a specific surface area of 246.717 m2/g, a surface hydroxyl density of 8.166 mmol/g, a length of 30 nm, and a narrow particle size distribution. Compared with the stirred tank reactor, the reaction time is reduced from 30 min to 4 min and the specific surface area is increased by 2.1 times in IS-RPB. The removal rate of nitrobenzene by IS-RPB-FeOOH can reach 94.3% after 40 min, which is 8.8% and 19.5% higher than that of FeOOH nanoparticles prepared using a stirred tank reactor (STR-FeOOH) and ozonation alone, respectively.