Electrocoagulation process for removing dyes and chemical oxygen demand from wastewater: operational conditions and economic assessment - a review

Electrocoagulation (EC) technique gained a significant attention owing to its efficiency in remov-ing colors and contaminations in industrial effluents discharged from numerous industries as textiles, pulp and paper industry, landfill leachate, food processing industry and tannery industry, etc. These effluents are characterized by a wide range of chemical oxygen demand (COD), heavy metals, suspended solids, turbidity and color levels. Most published works focused on the opti-mization of the operational parameters of EC in order to enhance the simultaneous abatement of soluble and colloidal pollutants. Indeed, EC is influenced by several operation parameters such as pH, applied current density, electrodes material and configuration, conductivity of the solution, electrode gap, electrolysis time and mixing rate. The present work handles the implied mechanisms in removing such contaminants from wastewater together with discussing the major operating parameters influencing the EC performance. Special emphasis is accorded to reducing COD and colors from wastewater. Comparing economically of EC with other alternatives is also conducted aiming at providing a reference for process selection. Economic assessment gives the opportunity for further optimizing the appropriate technology of wastewater treatment through the different strategies of cost optimization.