Investigation of the decomposition performances of Cu-EDTA using pulsed streamer discharge

The decomposition of Cu-Ethylenediaminetetraacetic Acid (Cu-EDTA) using a pulsed streamer discharge in contact with liquid is reported under various experimental conditions, and the efficacy of OH radicals is investigated. The change in Cu-EDTA concentration was characterized using high-performance liquid chromatography. H2O2, NO2−, NO3−, and O3 were detected using water inspection test kits and an UV-visual spectrophotometer. The OH yield was estimated using a colorimetric method with disodium terephthalate. The results revealed that approximately 70% of the Cu-EDTA decomposed with an energy efficiency of 15 mmol kWh−1 in the Ar discharge, whereas the decomposition rate and energy efficiency in the air discharge were 80% and 16 mmol kWh−1, respectively, within 60 min of treatment. The decomposition in Ar was primarily driven by the OH generated during discharge, whereas a combined effect of O3 and OH was observed during air discharge. The discharge-generated OH was the dominant species in Cu-EDTA decomposition in this study.