Removal of nitric oxide from simulated flue gas using aqueous persulfate with activation of ferrous ethylenediaminetetraacetate in the rotating packed bed

Nitric oxide being a major gas pollutant has attracted much attention and various technologies have been developed to reduce NO emission to preserve the environment. Advanced persulfate oxidation technology is a workable and effective choice for wet flue gas denitrification due to its high efficiency and green advantages. However, NO absorption rate is limited and affected by mass transfer limitation of NO and aqueous persulfate in traditional reactors. In this study, a rotating packed bed (RPB) was employed as a gas-liquid absorption device to elevate the NO removal efficiency (eta(NO)) by aqueous persulfate ((NH4)(2)S2O8) activated by ferrous ethylenediaminetetraacetate (Fe2+-EDTA). The experimental results regarding the NO absorption were obtained by investigating the effect of various operating parameters on the removal efficiency of NO in RPB. Increasing the concentration of (NH4)(2)S2O8 and liquid-gas ratio could promoted the oxidation and absorption of NO while the eta(NO) decreased with the increase of the gas flow and NO concentration. In addition, improving the high gravity factor increased the eta(NO) and the total volumetric mass transfer coefficient (K-G alpha) which raise the eta(NO) up to more than 75% under the investigated system. These observations proved that the RPB can enhance the gas-liquid mass transfer process in NO absorption. The correlation formula between K-G alpha and the influencing factors was determined by regression calculation, which is used to guide the industrial scale-up application of the system in NO removal. The presence of O-2 also had a negative effect on the NO removal process and through electron spin resonance spectrometer detection and product analysis, it was revealed that Fe2+-EDTA activated (NH4)(2)S2O8 to produce center dot SO4-, center dot OH and center dot O2-, played a leading role in the oxidation of NO, to produce NO3- as the final product. The obtained results demonstrated a good applicable potential of RPB/PS/Fe2+-EDTA in the removal of NO from flue gases.