Decolorization of organic dyes in water using non-thermal plassma

Abstract

Decolorization of azo dye methyl orange (MO) in aqueous solution was performed using non-thermal plasma in a dielectric barrier discharge device with the coaxial configuration. The results show that the average H₂O₂ accumulation rate is 0.73 mg/min (under the condition: discharge voltage 18 kV, solution volume of 500 ml, liquid flow rate of 100 ml/min, O₂ flow rate of 0.5 l/min). The influence of parameters, including the liquid flow rate, gas flow, initial dye concentration on the decolorization efficiency has been studied on the batch processing model After 12 minutes of plasma treatment of MO solutions with initial concentrations of 100, 200, 300, 400 and 500 mg/l, the decolorization efficiencies were of 94.2%, 84.5%, 80.1%, 70.5% and 61.6%, respectively. In particular, after 48 minutes of the operation, decolorization efficiency was over 99% in all samples, which shows that the energy efficiency increases as the initial concentration of MO increases