Degradation and mineralization of methylene blue by dielectric barrier discharge non-thermal plasma reactor

Advanced oxidation process based on dielectric barrier discharge at the gas water interface was used for the oxidative decomposition of dye contaminated wastewater. The advantage of plasma treatment over conventional physical methods of pollutants removal is the mineralization of pollutant, whereas in physical methods, pollutants may be transferred from one form to another. The effect of various parameters like applied voltage, gas flow rate, concentrations of dye, addition of Na2SO4 and Fe2+, formation of H2O2 and change in pH were investigated for methylene blue degradation. The high degradation yield up to 67 g/kW h was achieved during the present study. Hydrogen peroxide, a powerful oxidant formed during the reaction was confirmed and addition of Fe+2 improved the performance, possibly due to Fenton type reactions. It has been observed that dye degradation followed first order kinetics.

► Non-thermal plasma degradation and mineralization of methylene blue in water. ► Confirmation of mineralization by TOC and infrared gas analyzers. ► Improved performance with the addition of Fe+2 via Fenton type reaction. ► High energy efficiency for the dye removal (67 g/kW h). ► Confirmation of first order kinetics for the dye removal.