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

Abstract

BACKGROUND: How to control NO x emission in flue gas economically and efficiently is the focus in the field of energy and environment in the world. In this work, Fe 3 O 4 -magnetic microspheres were employed as the matrix with loading FeEDTA (where EDTA is ethylenediaminetetraacetic acid) to prepare magnetic denitrification absorbent Fe 3 O 4 @FeEDTA. The performance of nitric oxide (NO) removal using Fe 3 O 4 @FeEDTA dispersed in H 2 O 2 solution with ultraviolet (UV) was first investigated. RESULTS:The results showed that Fe 3 O 4 @FeEDTA could be used as a good catalytic oxidation denitrification agent. Increasing H 2 O 2 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. CO 2 hardly affected the removal of NO, while SO 2 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 Fe 3 O 4 @FeEDTA/H 2 O 2 was a catalysis-complexation-oxidation-absorption process, in which •OH was determined to be the main oxidizing species, and NO captured by Fe(II)EDTA was mainly oxidized by •OH to NO 3 − . CONCLUSION: The catalytic activity of Fe 3 O 4 @FeEDTA could maintain stability during the repeat experiment, realizing the recycling and reuse of Fe 3 O 4 @FeEDTA. The UV-Fe 3 O 4 @FeEDTA-activated H 2 O 2 advanced oxidation technology is suitable for wet denitrification.

Study on the Transport Properties of SO2 and NO at the Interface of H2O2 Solutions Using Molecular Dynamics

“…It should be due to the addition of H 2 O 2 molecules, and the interaction force became more complex. According to the reaction steps of SO 2 molecules in a H 2 O 2 solution, SO 2 molecules will first dissolve in water to form HSO 3 – and then be oxidized by •OH radicals . In Figure a,b, when SO 2 molecules were adsorbed on the surface of the solution, the H atoms of the H 2 O molecules were attracted and turned, which explained this phenomenon.…”

“…According to the reaction steps of SO 2 molecules in a H 2 O 2 solution, SO 2 molecules will first dissolve in water to form HSO 3 − and then be oxidized by •OH radicals. 39 In Figure 8a,b, when SO 2 molecules were adsorbed on the surface of the solution, the H atoms of the H 2 O molecules were attracted and turned, which explained this phenomenon. When the SO 2 molecules reached the surface of the solution phase, the O atoms of SO 2 faced the solution, and the H atoms of the H 2 O molecules were attracted to the top of the solution by SO 2 molecules.…”