Investigating the Result of Current Density, Temperature, and Electrolyte Concentration on COD: Subtraction of Petroleum Refinery Wastewater Using Response Surface Methodology

Electrochemical oxidation (EO) investigated chemical oxygen demand (COD) subtraction from petroleum refinery wastewater (PRW) as a capable remediation process. Titanium substrates coated with iridium–tantalum oxide mixtures (Ti/IrO2–Ta2O5) were used the dimensional stable anode (DSA). The Box-Behnken Design (BBD), statistical experimental design and response surface methodology (RSM), was to matrix current density, temperature, electrolyte (NaCl) concentration variables, COD removal efficiency factor. A second-order verifiable relationship between independent variables derived where analysis of variance displayed high coefficient determination value (R2 = 0.9799). predicted values calculated model equations very close highly significant. Based on BBD for optimum process conditions, temperature 7.5 mA/cm2, 42 °C 4.5 g/L, respectively. They resulting in 99.83% after 12-hour EO period.