Study on the influence of electrode materials in the low-voltage pulsed submerged arc plasma degradation of methylene blue

Abstract Low-voltage pulsed submerged arc (SA) plasma discharge is promising for water treatment due to its cost-effectiveness and high degradation efficiency. This study investigated methylene blue (MB) degradation with different electrode pairs, including graphite and iron as anodes, while iron, titanium, and tungsten as cathodes. A maximum removal ratio of 99.39% was achieved with a tungsten cathode and iron anode in 70 s. The experimental results indicated that electrode erosion might contribute to MB removal through adsorption and chemical reactions. Additionally, the iron ion hydrolysis produced flocculent precipitates, which further improved the MB degradation. This study provides insights into electrode material selection and the mechanisms that influence MB degradation.