Electrocoagulation technology for wastewater treatment: insights on design, applications, and challenges

The electrocoagulation process has emerged as a promising alternative for wastewater treatment due to its high versatility for contaminant removal. The objective of this review is to provide a critical analysis of electrocoagulation technology, including its operating principles, fields of application, advantages, and limitations in wastewater treatment. In this process, metal electrodes release coagulant species directly into the water, which then destabilise suspended, dissolved, and colloidal pollutants. The efficiency of EC is strongly dependent on design and operating factors, including electrode material, current density, electrode spacing, pH, and hydraulic conditions. The present work reviewed municipal and industrial wastewater treatment using EC technology in batch, continuous, and pilot-scale systems, focusing on turbidity, nutrients, metals, dyes, oils, and organic pollutant removal. However, practical challenges have to date limited its widespread adoption, requiring research and development. Issues such as electrode passivation, sludge generation, energy demand, and scale-up from laboratory to field conditions remain significant ones. Recent research has focused on optimising reactor configurations, coupling EC with other treatment processes, and exploring renewable energy inputs to improve overall sustainability. By addressing these design and operational concerns, the strong potential of EC as a cost-effective and adaptable solution to meet growing wastewater treatment demands could be fully realised.