[Catalytic degradation of dimethyl sulfoxide in aqueous solutions by liquid-phase pulsed high voltage discharge]

Fenton catalytic degradation of dimethyl sulfoxide (DMSO) by using liquid-phase pulsed high voltage discharge was carried out. The discharge was driven by a self-made pulsed power supply providing a pulse rising time of 400 ns, discharge repetition rate of 96.2 Hz, peak voltage of 20 kV. The side surface of discharge electrode was insulated in order to limit the discharge current, followed by estimating its effect on single pulse power. The effects of aqueous conductivity, Fe(II), and O2 flow rate on liquid-phase discharge induced DMSO degradation and aqueous conductivity on corresponding H2O2 yield were investigated. The concentrations and selectivities of intermediates of DMSO degradation, were also studied. The results indicated that when using the insulated electrode, single pulse power had a limiting value with increasing the aqueous conductivity; DMSO degradation rate was reduced with increasing the aqueous conductivity and O2 flow rate,whereas Fe(II) showed a Fenton catalytic oxidation of DMSO; 80% of DMSO degradation rate was achieved at the pulsed high voltage discharge time of 45 min and the resultant biodegradability was enhanced by at least 32%-48%; the maximum energy efficiency in G(37%) was 0.0087 mol/(kW x h). The study suggested that the liquid-phase plasma combined catalyst promised the potential of organic compound degradation.