The comparison of the degradation efficiency of two electrodes (Ti/RuO₂–IrO₂ and SnO₂) has been evaluated using Methylene Bleu (MB) dye. The effect of several parameters on the degradation process was evaluated and optimized. It was figured out that Ti/RuO₂–IrO₂ has led to more performant degradation capacity compared to that of SnO₂. The optimum degradation efficiency of MB dye on the Ti/RuO₂–IrO₂ electrode was achieved at j = 40 mA cm⁻², [NaCl] = 0.1 mol L⁻¹, pH_i = 3, [MB] = 100 mg L⁻¹ and T = 25°C. The complete color elimination with 73% of COD elimination was achieved within 90 min of electrolysis.

The electrochemical oxidation of the Rhodamine B dye (Rh-B) was carried out using dimensionally stable type anode (DSA, Ti/Ru_0.3Ti_0.7O₂). The work was performed using the electrochemical flow cell system. The effect of several operating factors, such as supporting electrolytes, current density, electrolysis time, temperature, and initial concentration of Rh-B dye, were investigated. The UV-visible spectroscopy and chemical oxygen demand (COD) measurements were conducted to monitor the removal and degradation of Rh-B. The best color removal achieved was found to be 98.3% after 10 min applying 3.9 mA·cm⁻² as a current density using 0.07 mol·L⁻¹ of NaCl. Meanwhile, the highest COD removal rate (93.0%) was obtained for an applied current density of 3.9 mA·cm⁻² as the optimal operating condition after 180 min reaction time, with 2.98 kW h·m⁻³ as energy consumption. This shows that the best conditions for color removal are not certainly the same as those for the COD removal. The rises in the concentration of NaCl, and applied current increased the Rh-B color removal rate. The decline in Rh-B dye concentration followed pseudo-first-order kinetics. The obtained values of apparent rate constant were increased by increasing chloride ion concentration. It is concluded that the electro-oxidation on DSA electrode using a flow cell is a suitable process for the removal of Rh-B dye in aqueous solutions.

The electrochemical oxidation of a real wastewater discharged by the baths of “Dar Dbagh” tannery (DDT) in Fez city (Morocco) was performed using Ti/Ti_0.7Ru_0.3O₂ anode (a dimensionally stable anode (DSA)-type electrode) underflow condition. The effect of different operational parameters, namely chloride ions concentration, electrolysis time, current density, initial pH, and temperature has been studied in detail. The discoloration and chemical oxygen demand (COD) removal have been taken as the key experimental indicators to monitor the electrochemical treatment process of DDT wastewater. The obtained results have shown that the best degradation rates (i.e., 100% and 56% of de-colorization and COD removal, respectively) were accomplished under acidic conditions at 20 mA cm⁻² as a current density in the presence of 0.033 M Na₂SO₄ + 0.800 M NaCl as supporting electrolyte at room temperature. The maximum reduction of the effluent COD attained using Ti/Ti_0.7Ru_0.3O₂ anode consuming 39.24 kWh per m³ clearly shows that DSA electrodes could be a good alternative for the remediation of DDT effluents.