Theoretical investigation of the influence of operating conditions on the treatment performance of an electrically-induced membrane bioreactor

This study aimed at investigating the impact of operating conditions on the treatment performance of an alternative method of wastewater treatment. The investigations were carried out in a hybrid reactor which combined simultaneous biodegradation of organic pollutants through microorganisms, membrane filtration through a submerged microfiltration (MF) membrane, and electrocoagulation process via application of electric field intermittently supplied. The theoretical investigations included mathematical modelling to determine the impact of the variations of process parameters such as current density (CD), hydraulic retention time (HRT), sludge retention time (SRT) and pore diameter of anode (dp) on the mixed liquor volatile suspended solids (MLVSS), and the removal of chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), iron (Fe), nickel (Ni), and chromium (Cr) from raw municipal wastewater directly supplied from the main sewer (without pre or primary treatment) at Masdar City, Abu Dhabi, United Arab Emirates. CD was varied between 5 and 20 A/m2 with a step size of 10 A/m2; HRT was varied by changing the influent flow rate between 20 and 50 L/d with a step size of 10 L/d; SRT was changed from 5 to 20 d using a step size of 5 d; and dp was changed from 0.2 to 0.5 cm. It was observed from the theoretical results obtained that the removal of COD, TN, and TP from the wastewater was favored in the hybrid unit by increasing the CD or HRT and decreasing the porosity of anode.