Methylene Blue Decomposition Via Various In-liquid Plasma Methods

Abstract

At present, the two main wastewater treatment methods are biological treatment and coagulation sedimentation treatment. However, wastewater discharged from dyeing factories cannot be adequately treated because it contains persistent organic substances. The purpose of this study is to develop a treatment for dye wastewater using plasma under atmospheric pressure. The decolorization processing characteristics were investigated using a methylene blue (MB) solution as a model for dye wastewater. The study revealed that an MB solution could be decolorized using plasma treatment, and the conversion rate was correlated to the MB concentration. The discharge method and liquid temperature affected the conversion of MB, and the conversion rates and energy efficiencies were compared for each condition. Additionally, flow-type plasma that took in air from the side of the reaction vessel could treat MB the most efficiently and could be stably operated for considerable time. This process may eventually be used to treat dye wastewater discharged from actual dyeing factories.