Electrochemical Oxidation of Textile Dye House Wastewater Using Graphite (Gr) and Modified Graphite (Gr/CuO & Gr/ZnO) Electrodes

Textile dye house wastewater presents significant environmental challenges due to its high pollutant load and complex chemical composition, necessitating advanced treatment technologies for effective remediation. Two modified graphite electrodes Gr/CuO and Gr/ZnO, prepared by the electrospinning process , were utilized as anodes for the electrochemical oxidation (EO) of real textile dye house wastewater.. Also, a bare graphite electrode was used as a reference electrode for comparison purpose. Key operating parameters affecting the treatment process, including current density, pH, supporting electrolyte, and electrolysis duration, were systematically studied and optimized.. Graphite electrodes were modified by first transition-metal (Cu &Zn) oxide nanofibers by electrospinning and controlled calcination process. Powder X-ray diffraction and scanning electron microscopy were used to characterise the morphology and phase composition of the electrodes. The results show that the produced nanofibers exhibit a continuously twisted three dimensional scaffold structure and are composed of neat nanocrystals with a necklace-like setup. In order to compare the removal efficiencies of the two modified electrodes and the bare one, a batch wise electrochemical batch system was investigated. The optimal operational parameters for all three electrodes were identified as pH 5, a current density of 25 mA/cm², an electrolysis duration of 50 minutes, and an NaCl concentration of 2 g/L.. Highest removal efficiencies of 75.1% and 91.2% for COD and color were obtained for the modified Gr/ZnO electrode. Energy consumption and operating cost of 1 m3 of wastewater for Gr/ZnO electrode at the optimum conditions were determined to be 76.2 kWh and 3.5 US$, respectively.