Removal of Nitric Oxide by Aqueous Sodium Persulfate Simultaneously Activated by Temperature and Fe2+ in a Lab-scale Bubble Reactor

Nitric oxide (NO) removal by aqueous sodium persulfate (Na2S2O8) simultaneously activated by temperature and Fe2+ was studied in a lab-scale bubble reactor. The effects of Na2S2O8 (0.01-0.20 M), Fe2+ (0.00-0.10 M), gas-phase NO (500-1000 ppm) concentrations, and temperatures (23-90 degrees C) were investigated. NO fractional conversion at all temperatures with and without the presence of Fe2+ increased sharply with persulfate concentration up to about 0.10 M before leveling off. At 0.10 M Na2S2O8 and 0.01 M Fe2+ concentrations, conversions of up to 79% and approximately 100% were observed at 70 and 90 degrees C, respectively. Increased temperature led to increased conversions of NO at all persulfate levels, and activation by 0.01 M Fe2+ further improved NO conversion by similar to 10% at all temperatures. The chemistry of NO removal and proposed reaction pathways are discussed. The results demonstrated the feasibility of improved NO aqueous scrubbing by temperature- and Fe2+-activated persulfate.