Optimizing decolorization of Methylene Blue and Methyl Orange dye by pulsed discharged plasma in water using response surface methodology

Dye removal using pulsed discharged plasma in water requires a proper process parametric study to determine its optimal performance characteristics. Response surface methodology was used to find out the major factors influencing Methylene Blue (MB) and Methyl Orange (MO) removal efficiency and the interactions between these factors (ultrasonic power, gas flow rate, and electrode spacing), and optimized the operating variables as well. Regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination value of 0.9960 and 0.9861 for MB and MO, respectively. Under the experimental conditions: gas flow rate 0.1 m3/h, electrode spacing 10 mm for all the dyes, and ultrasonic power 80 and 90 W for MB and MO, the highest dye removal efficiency were achieved 94.5% and 80.2% for MB and MO. The optimal results suggested that pulsed discharged plasma oxidation process was a rapid, efficient, and low energy consumption technique to remove the dyes wastewater.