A systematic diagnosis of state of the art in the use of electrocoagulation as a sustainable technology for pollutant treatment: An updated review

Electrocoagulation (EC) and electrocoagulation-flotation (ECF) are of widespread interest owing to their effectiveness for the simultaneous abatement of a broad range of pollutants in drinking and waste waters, but their capability can vary significantly depending on the operating conditions. The effect of operating conditions on the performance of EC has been the subject of much debate over the last few decades. This review aims to focus on the application of EC/ECF processes for pollutants removal under different operating conditions, emphasizing the principal issues that compose the foundation of EC/ECF. It has been found that the current density (typically 1–20 mA/cm2), type of electrode (Al or Fe), and electrolysis time are the key process parameters that influence performance. Although some key mechanisms of pollutant abatement in EC/ECF processes have been identified, recent studies have begun to reveal how the underlying removal mechanisms using the EC/ECF processes depend on the nature of pollutant. Key mechanisms of pollutant abatement include charge neutralization, reduction–oxidation, and precipitation/co-precipitation. The development of improved or innovative cell designs, as well as systematic modeling of EC reactors, are needed. Future research focused on hybrid technologies with cost-effective energy supply may lead to innovative treatment options for wastewater treatment.