Ozonation-assisted electro-membrane hybrid reactor for oily wastewater treatment: A methodological approach and synergy effects

Wastewater produced from oil and gas industries contains high levels of organic and inorganic pollutants in the form of emulsions sized below 10 μm. The beneficial reuse of oily wastewater requires advanced treatment methods to remove these emulsions and promote cleaner production. This work has attempted to investigate the hybridization of electrocoagulation (EC) process, ceramic microfiltration membrane, and ozonation as a one-pot solution for the treatment of oily wastewater. The variables in this study included hydraulic retention time (HRT), aeration, current density (CD), mode of power supply, and initial pH of the sample. Aerated electro-membrane reactor contributed to a maximum COD reduction of 18.0% as opposed to 53.1% for the ozonated reactor. The effectiveness of the novel hybrid reactor could be attributed to the enhancement of electrocoagulation process by the ozone, which facilitated size-exclusion by the submerged membrane. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were performed to characterize the generated foam, electrodes, and sludge. The present findings indicate that the ozonation-assisted electro-membrane hybrid method has the potential to be employed for the treatment of oily wastewater.