FORMATION OF HYDROXYL RADICALS, HYDROGEN-PEROXIDE AND AQUEOUS ELECTRONS BY PULSED STREAMER CORONA DISCHARGE IN AQUEOUS-SOLUTION

The initiation reaction rate constants for the formation of hydroxyl radicals, hydrogen peroxide, and aqueous electrons using a pulsed streamer corona discharge in aqueous solutions are determined in the present study. The free radical scavenging property of carbonate ions was used to determine the initiation rate constants for the formation of hydroxyl radicals and hydrogen peroxide from the pulsed streamer corona discharge. The effects of average current, voltage, and power input on the initiation rate constants were also studied. A reactor model including known chemical reaction kinetics was developed for the degradation of phenol, and the initiation rate constant for aqueous electrons was determined by fitting the experimental data of phenol degradation to the model. Transient concentration profiles predicted by the model were compared to those of experiments for the formation of hydrogen peroxide in deionized water and for the degradation of hydroquinone. It was observed that the model results match experimental results satisfactorily for the formation of hydrogen peroxide and qualitatively follow the experimental results for the degradation of hydroquinone. The model was improved by considering that the reaction rate constants vary with the current in the reactor. The current was observed to vary with time for the cases where no salts were added to the reactor. It was observed that the improved model follows the experimental results satisfactorily for high initial concentrations (> 5.4 x 10(-5) M) of hydroquinone.