Effective nitric oxide removal from flue gas using UV/H2O2 solution catalyzed by Fe3O4@FeEDTA

BACKGROUND: How to control NOx emission in flue gas economically and efficiently is the focus in the field of energy and environment in the world. In this work, Fe3O4-magnetic microspheres were employed as the matrix with loading FeEDTA (where EDTA is ethylenediaminetetraacetic acid) to prepare magnetic denitrification absorbent Fe3O4@FeEDTA. The performance of nitric oxide (NO) removal using Fe3O4@FeEDTA dispersed in H2O2 solution with ultraviolet (UV) was first investigated. RESULTS: The results showed that Fe3O4@FeEDTA could be used as a good catalytic oxidation denitrification agent. Increasing H2O2 concentration and O-2 concentration could promote NO absorption. NO removal efficiency increased as pH value increased from 1.5 to 3.0, then decreased when pH continued to increase. The elevated temperature was conducive to NO removal. CO2 hardly affected the removal of NO, while SO2 with high concentration was not conducive to NO absorption. In addition, the NO removal mechanism was preliminarily analyzed with X-ray photoelectron spectrometry, electron spin resonance and ion chromatography. The mechanism study indicated that NO removal by Fe3O4@FeEDTA/H2O2 was a catalysis-complexation-oxidation-absorption process, in which (OH)-O-center dot was determined to be the main oxidizing species, and NO captured by Fe(II)EDTA was mainly oxidized by (OH)-O-center dot to NO3-. CONCLUSION: The catalytic activity of Fe3O4@FeEDTA could maintain stability during the repeat experiment, realizing the recycling and reuse of Fe3O4@FeEDTA. The UV-Fe3O4@FeEDTA-activated H2O2 advanced oxidation technology is suitable for wet denitrification. (c) 2023 Society of Chemical Industry (SCI).