Investigation of oil content removal performance in real oily wastewater treatment by electrocoagulation technology: RSM design approach

The current investigation attempts to treat real oily wastewater produced from the Al-Muthanna petroleum refinery with a modernized electrocoagulation reactor (ECR) to diminish the oil content (OC) to levels suitable for consumption. In the continuous ECR, a two-sided finned (2SF) cathode tube was situated between two tubular anodes, with the active area of the cathode being significantly more extensive than its immersed volume. Circular aluminum tubes were employed as a sacrificial anode in this procedure, while a stainless steel finned cylinder was used as a cathode. Each of these electrodes was related to a DC power source in a monopolar-parallel mode. The electrolysis period (4-60 min), current density (0.63-5.0 mA/cm2), and flow rate (50-150 ml/min) were studied for their effects on OC removal efficiency. Increasing the flow rate reduces oil removal efficacy, but increasing current density and electrolysis time improves it. At optimized values of 60 min of electrolysis, 5 mA/ cm2 of current density, and 50 ml/min of flow rate, the removal efficiency for oil content (OC) was 99%, with energy consumption of 4.342 (kWh/kg OC), theoretical electrodes consumption of 0.55 g, and actual electrodes consumption of 0.29 g. This research validated the new reactor's ability to treat real oily wastewater under operational parameters. It could be used as a precursor to other traditional procedures.