Discoloration of a textile dyes mixture in an aqueous solution using a corona discharge

A batch reactor and a corona discharge were used for the degradation of a mixture of azo dyes, Acid Black 52 and Acid Black 210, in an aqueous solution using iron filings (Fe2+) as a catalyst. The plasma at atmospheric pressure was generated on the surface of the liquid using a constant electrical power of 80 W. The physicochemical properties of the liquid, electrical conductivity, pH, volume, and temperature were measured. Ultraviolet-visible spectrophotometry was used to determine the kinetics of the oxidation process. In addition, optical emission spectroscopy, CO2 production, total organic carbon (TOC), and chemical oxygen demand experiments were also carried out. The dye mixture illustrated discoloration of 95%–99% at the treatment time of 180 min and a 92% reduction in TOC. In the optical emission spectrum of the plasma, species such as OH, Ha, Hb, N2, and Na were identified. The electron temperature and electron density of the plasma were also calculated.