Removal of NOx and SO2 from the Coal-Fired Flue Gas Using a Rotating Packed Bed Pilot Reactor with Peroxymonosulfate Activated by Fe(II) and Heating

Abstract

An advanced oxidation process involving combined activation of peroxymonosulfate (PMS) by Fe(II) ions and heating for NOx and SO2 removal from coal-fired flue gas was conducted for the first time in a rotating packed bed (RPB) pilot reactor. The major influencing factors, radical species, reaction mechanisms and products, the mass transfer process, and the kinetics of simultaneous removal of NOx and SO2 were investigated. The results indicated that the NO removal efficiency reached above 70%, while SO2 and NO2 were almost completely removed. As the temperature increased, the NO removal efficiency increased. Moreover, the intensity of SO4•–, •OH, and 1O2 radicals generated by the activated PMS and •NO radical converted by the radical–radical reaction enhanced with the increasing temperature, assessed by the electron spin resonance spectroscopy test. The increased liquid flow led to a higher NO removal efficiency, and the increased gas flow played the opposite role. The increased rotational speed first resu...