electrochemical oxidation of wastewater contaminated with astrazon red violet 3rn dye on ti/iro₂/ruo₂: evaluation of process parameters, kinetics, and energy consumption

The performance of the electrochemical oxidation of wastewater contaminated with astrazon red violet 3rn dye on ti/iro₂/ruo₂ was evaluated under a range of significant process variables: support electrolyte type and concentration, initial dye concentration, ph, current density, and temperature. arv-3rn dye removal efficiency was over 90% at the high concentrations of nacl (≥ 5.0 mm) and lower ph values (3.0 ≤ ph≤ ~7.5). at the same time, the temperature increases promoted faster degradation and less energy consumption except at 10°c temperature. while the increase in the initial dye concentration had a negative effect on the removal efficiency (from 99.84% to 65.02%), energy consumption increased from 2.5 kw-h/m3  to 3.25 kw-h/m3. although the change in applied current density did not cause a significant difference in the removal efficiency (from 99.34% to 92.79%), it caused the energy consumption to increase from 3.10 kw-h/m3 to 25.767 kw-h/m3. electrooxidation kinetics were evaluated using pseudo-zero-order, pseudo-first-order, and pseudo-second-order models. kinetic data fitted best pseudo-first-order model. the activation energy (ea) of the eaop process calculated using the arrhenius equation is 13.707 kj/mol. thermodynamic parameters δh°, δs°, and δg° evaluated by eyring’s equation calculated 11.196 kj/mol, -0.1244 kj/mol, and 47.662 for 293 k, respectively.