Kinetics and modeling of the removal of nitric oxide by aqueous sodium persulfate simultaneously activated by temperature and Fe²⁺

The chemistry and kinetics of NO removal by aqueous solutions of sodium persulfate (Na₂S₂O₈) simultaneously activated by temperature and Fe²⁺ were studied in a bubble reactor. Reaction pathways were proposed and a mathematical model utilizing the pseudo-steady-state-approximation technique and film theory of mass transfer were developed. The model was solved numerically using the fourth order Runge-Kutta method in Matlab to obtain species concentrations; correlate experimental data; and estimate mass transfer and kinetic rate parameters. The model was used to investigate the effects of Na₂S₂O ₈ (0.01-0.2 M), Fe²⁺ (0-0.1 M), gas-phase NO (500-1000 ppm) concentrations and temperatures (23-90 C), and is a follow-up to an experimental study, which demonstrated that Fe²⁺ activation further improved NO conversion by ∼10% at all temperatures. The model results, which appeared to fit those of the experiments remarkably well, were discussed and predicted kinetic data compared with available literature values.