Oxidation Removal of Nitric Oxide from Flue Gas Using an Ultraviolet Light and Heat Coactivated Oxone System

The oxidation removal process of nitric oxide (NO) from flue gas using an ultraviolet (UV) light and heat coactivated oxone (potassium peroxymonosulfate, 2KHSO 5 ·KHSO 4 ·K 2 SO 4 ) system in an UV (254 nm)-impinging stream reactor was studied. The main process parameters (e.g., light intensity, oxone concentration, solution temperature, solution pH, flue gas composition, and flow rate of flue gas and solution), products, mechanism, and kinetics of NO removal were studied. The results show that UV and oxone have a significant synergistic effect for promoting free radical production and improving NO removal. NO removal was improved via increasing the light intensity, oxone concentration, or solution flow rate and was inhibited with increasing the NO concentration, SO 2 concentration, or flue gas flow rate. Solution temperature and pH have double impacts on NO removal. UV light activation for oxone is the main source of SO 4 – • and • OH. Heat activation for oxone is the complementary source of SO 4 – • and • OH. SO 4 – • and • OH are the key oxidizing agents and play an important role in NO removal. Oxone plays a complementary role in NO removal. The NO removal process is a fast reaction and meets a total 1.44 order reaction (i.e., 1.0 order for NO and 0.44 order for oxone). The key kinetic parameters of NO removal were also determined.