Synergistic degradation of malachite green by water surface plasma combined with Fe²⁺/PMS

Abstract

Water surface plasma (WSP) discharge technology coupling with Fe2+ and peroxymonosulfate (PMS) was investigated for the degradation of malachite green (MG) dye wastewater. The effects of Fe2+ dosage, PMS dosage, input voltage and solution initial conductivity on the degradation of MG were investigated. When the Fe2+ dosage was 125 μM, PMS dosage was 0.5 mM and input voltage was 16 kV, the degradation performance and reaction rate of MG reached 96.3% and 0.219 min−1 within the discharge time of 15 min. When increasing the initial conductivity from 31.1 μS/cm to 1000 μS/cm, degradation efficiency of MG decreased from 97.9% to 94.1% with the decrease of only 3.8% and degradation rate declined by only 0.074 min−1.