Multivariate optimization and application verification of electrochemical oxidation process for reactive dye wastewater generated by washing

Abstract

At present, organic wastewater containing dyes has become one of the main threats to the environment, and wastewater pollution caused by dyes released from fabrics during home washing also accounts for a large proportion. In this study, Ti/IrO₂ electrodes for dye waste degradation were designed and prepared with Reactive Yellow 210 (RY 210), Reactive Blue 19 (RB 19) and Reactive Blue 21 (RB 21) solutions, and a laboratory electrochemical reactor was constructed. Secondly, in the reactor, the effects of current density (20–60 mA cm⁻²), electrolyte concentration (NaCl, 0.01–0.03 M L⁻¹), and initial dye concentration (30–70 mg L⁻¹) on the COD degradation rate and energy consumption of the dye solution were explored, and the parameters were optimized by the Box-Behnken design, and the equipment was realized in the washing machine. The results showed that the effect of degradation parameters on the degradation of the three groups of dyes was: current density > initial dye concentration > electrolyte concentration. Through parameter optimization, the average COD degradation rates of the three groups of dyes, Reactive Yellow 210 (RY 210), Reactive Blue 19 (RB 19) and Reactive Blue 21 (RB 21), reached 50.71%, 41.65%, and 33.12%, respectively, and the degradation energy consumption decreased by the same trend as 29.91%, 26.49%, and 65.91%, respectively.