A state-of-the-art review on electrocoagulation (EC): An efficient, emerging, and green technology for oil elimination from oil and gas industrial wastewater streams

Abstract

Different industries such as petroleum refineries, food processing, restaurants, marine produce oily wastewaters with widely variable compositions and high pollutant levels. Studies have shown that efficient oil removal is achieved with electrocoagulation, EC, which is considered a new and effective wastewater treatment method that combines coagulation, flotation, sedimentation, and electrochemistry. During the EC process, metal ions are dissociated by applying an electric current, which hydrolyzes them and generates flocs to remove pollutants from the wastewater. The current study provides an overview of emerging electrochemical technology for oil-containing wastewater treatment with an overview of the origin and characteristics of oily wastewater. The treatment techniques for oily wastewater established thus far are briefly discussed. This review focuses on oil removal from polluted water by the EC process. Additionally, EC process efficiency, statistical research, and present challenges were discussed and reviewed. Some recommendations for future improvement trends of the EC method are presented.