Treatment of Dyeing Wastewater by Using Positive Pulsed Corona Discharge to Water Surface

Abstract

This study investigated the treatment of textile-dyeing wastewaterby using an electrical discharge technique (positive pulsed coronadischarge). The high-voltage electrode was placed above the surfaceof the wastewater while the ground electrode was submerged in thewastewater. The electrical discharge starting at the tip of the highvoltage electrode propagated toward the surface of the wastewater,producing various oxidative radicals and ozone. Oxygen was used asthe working gas instead of air to prevent nitrogen oxides fromforming. The simulated wastewater was made up with amaranth, whichis a kind of azo dye. The results obtained showed that thechromaticity of the wastewater was almost completely removed withinan hour. The ultraviolet/visible spectra of the wastewater treatedby the electrical discharge revealed that the total hydrocarbonlevel also decreased significantly.