Abstract
This study examines the water purification by cylindrical wetted-wall reactor using gas corona discharge. In this reactor, a cylindrical anode and a wire cathode are set apart from each other coaxially in an atmospheric air to generate corona discharge. This reactor is improved by modification from the previous plate anode to the present cylindrical anode. It is expected that reactive radicals produced in a plasma region around a wire cathode in a gas phase can efficiently reach the surface of a falling-water film on the cylindrical anode so that reactive species such as an OH radical can be effectively produced in water. In this study, aqueous phenol was decomposed using the cylindrical-anode reactor to evaluate its efficiency. As a result, the electron efficiency and energetic efficiency of the present reactor were respectively 2-3 and 3-4 times higher than those of the previous plate-anode reactor. In addition, the energetic efficiency per radical-producing plasma region length of the present reactor was 2 orders higher than that of the previous reactor. The experiments were carried out in variety of conditions in which water flow rates, discharge currents, radius of cylindrical anodes, were varied. In addition, the removal processes of phenol and byproducts in these experiments are modeled with numerical simulation based on their oxidative reactions.
