A pulseless corona-discharge process for the oxidation of organic compounds in water

Ozone is widely used to deactivate microorganisms and remove organic contam inants in water industries. However, interest also exists in using radical species, which are stronger oxidants than ozone, in such processes. One mea ns of producing radical species is by corona discharge. This work investiga tes the use of a novel pulseless corona-discharge system for the removal of organic substances. The method combines corona discharge with electrohydro dynamic spraying of oxygen, forming microbubbles. Experimental results show that pulseless corona discharge effectively removes organics, such as phen ol and methylene blue, in deionized water. The corona-discharge method is d emonstrated to be comparable to the direct use of ozone at a high applied v oltage. The results also show that a minimum applied voltage exists for an effective operation of the corona-discharge method. In this work, the minim um applied voltage is approximately 4-4.5 kV over a 3-cm distance between t he electrodes. The kinetic rate of phenol degradation in the reactor is mod eled. Modeling results show that the dominant species of the pulseless coro na-discharge reactor are hydroxyl radical and aqueous electron. Several rad ical species produced in the pulseless corona-discharge process are identif ied experimentally. The major species are hydroxyl radical, atomic hydrogen species, and ozone.