Removal of NO in simulated flue with aqueous solution of peroxymonosulfate activated by high temperature and Fe(II)

Abstract

In this article, a novel control strategy on nitric oxide (NO) removal from simulated flue gas by high temperature and transition metal Fe(II) to activate peroxymonosulfate (PMS) to generate sulfate radicals (SO4·-) and hydroxyl radicals (OH) was investigated for the first. The high oxidation capacity of PMS, in combination with the high activation performance of Fe(II) ions, made the processes significantly effective for NO removal, and a removal efficiency of more than 86% was observed after 25 min treatment. Some experiments were optimized to select optimal experimental parameters: the molar ratio of PMS/Fe(II), solution pH value and activation temperature in terms of NO removal efficiency. The effect of free radical quenching, combined with electron spin-resonance (ESR) analysis confirmed that the presence of SO4·- and OH radicals, and verified that SO4·- was the dominated radical during NO removal process and the strategy of heating and Fe(II) had stronger function to activate PMS. The classical steady-state approximation technique was adopted to obtain the kinetic model of the whole reaction, and the result satisfactorily interpreted the experimental data and had the good reliability (0.978) and (0.988). The removal process of NO from simulated flue gas by the PMS–Fe(II) systems was a pseudo-first-order reaction.