A study on simultaneous removal of NO and SO2 by using sodium persulfate aqueous scrubbing

Nitric oxide (NO) removal and sulfur dioxide (SO2) removal by sodium persulfate (Na2S2O8) were studied in a Bubble Column Reactor. The proposed reaction pathways of NO and SO2 removal are discussed. The effects of temperatures (35–90 °C), Na2S2O8 (0.05–0.5 mol·L-1), FeSO4 (0.5–5.0 m mol·L-1) and H2O2 (0.25 mol·L-1) on NO and SO2 removal were investigated. The results indicated that increased persulfate concentration led to increase in NO removal at various temperatures. SO2 was almost completely removed in the temperature range of 55–85 °C. Fe2+ accelerated persulfate activation and enhanced NO removal efficiency. At 0.2 mol·L-1 Na2S2O8 and 0.5–1.0 mmol·L-1 Fe2+, NO removal of 93.5％–99％ was obtained at 75–90 °C, SO2 removal was higher than 99％ at all temperatures. The addition of 0.25 mol·L-1 H2O2 into 0.2 mol·L-1 Na2S2O8 solution promoted NO removal efficiency apparently until utterly decomposition of H2O2, the SO2 removal was as high as 98.4％ separately at 35 °C and 80 °C.