Prediction and inhibition of the N2O accumulation in the BioDeNOx process for NOx removal from flue gas

BioDeNO _x process, which combines the advantages of the chemical absorption and biological reduction processes, is regarded as a promising candidate for NO removal from the flue gas. In the BioDeNO _x , N₂O was accumulated in the process of the biological reduction of Fe^II(EDTA)-NO. In this work, the pathway of the Fe^II(EDTA)-NO reduction was investigated and a mathematic model was developed to evaluate and predict the accumulation of N₂O. Furthermore, parametric tests such as the effects of the C/N ratio (molar ratio of carbon/nitrogen), electron donor, and sulfite concentrations on N₂O accumulation were investigated. Experimental results revealed that N₂O accumulation was inhibited with a high C/N ratio (2.4), sufficient electron donor, and a low sulfite concentration. In addition, compared with the inorganic electron donor (Fe^II(EDTA)), the organic electron donor (glucose) was beneficial for microorganism metabolism and N₂O accumulation inhibition. This work will provide significant insight into the inhibition of N₂O accumulation during the operation of BioDeNO _x and advance this novel process for the industrial application.