This review provides a critical and technically grounded assessment of continuous electrocoagulation processes (CEPs) for the treatment of industrial inorganic pollutants, emphasizing recent innovations, methodological developments, and practical outcomes. A comprehensive literature survey indicates that 53 studies published over the past 25 years have investigated CEPs for inorganic contaminant removal, with 36 focusing on standalone electrocoagulation systems and 17 exploring integrated CEPs approaches. Recent advancements in reactor design, such as enhanced internal mixing, optimized electrode geometry, and modular configurations, have significantly improved treatment efficiency, scalability, and operational stability. Evidence indicates that CEPs can achieve high removal efficiencies for a wide range of inorganic contaminants, including fluoride, arsenic, heavy metals (e.g., chromium, lead, nickel, iron), nitrates, and phosphates, particularly under optimized operating conditions. Compared to conventional treatment methods, CEPs offer several advantages, such as simplified operation, reduced chemical consumption, lower sludge generation, and compatibility with renewable energy sources and complementary processes like membrane filtration, flotation, and advanced oxidation. Despite these promising outcomes, industrial-scale implementation remains constrained by non-standardized reactor designs, variable operational parameters, electrode passivation, high energy requirements, and limited long-term field data. Furthermore, few studies have addressed the modeling and optimization of integrated CEPs systems, highlighting critical research gaps for process enhancement and reliable scale-up. In conclusion, CEPs emerge as a novel, adaptable, and potentially sustainable approach to industrial inorganic wastewater treatment. Its future deployment will rely on continued technological refinement, standardization, validation under real-world conditions, and alignment with regulatory and economic frameworks.

Electrocoagulation (EC) processes have emerged as an efficient solution for different inorganic and organic effluents. The main characteristics of this versatile process are its ease of operation and low sludge production. The literature indicates that EC can be successfully used as a single process or a step within a combined treatment system. If used in a combined system, this process could be employed as a pre-, a post-, or middle treatment step. Additionally, the EC process has been used in both continuous and batch modes. In most studies, EC has achieved significant improvements in the treated water quality and relatively low total energy consumption. This review presents a comprehensive evaluation and analysis of standalone and combined continuous EC processes. The influence of key operational parameters on continuous EC performance is thoroughly discussed. Furthermore, recent advancements in reactor design, modeling, and process optimization are addressed. The benefits of integrating other treatment processes with the EC process, such as advanced oxidation, membranes, chemical coagulation, and adsorption, are also evaluated. The performance of most standalone and combined EC processes used for organic pollutant treatment and published in the last 25 years is critically analyzed. This review is expected to give researchers many insights to improve their treatment scenario with recent and efficient environmental experiences, sustainability, and circular economy. The clearly presented information is expected to guide researchers in selecting efficient, cost-effective, and time-saving treatment alternatives. The findings ensure the considerable potential of continuous EC treatment processes for organic pollutants. However, more research is warranted to enhance process design, operational efficiency, scale-up, and economic viability.

Greywater (GW) treatment by the electrocoagulation (EC) technique alone might not meet the required standards in terms of pollutant removal, specifically when GW contains high loads of pollutants. In this preliminary study, a sand filtration (SF) unit was integrated with the EC technique as a pretreatment step to enhance the EC process for treating high-loaded GW. Three different voltage gradients were investigated (5 V/cm, 10 V/cm, and 15 V/cm) in the EC unit. The results demonstrated that the pretreatment SF step can contribute significantly to reducing pollutant concentrations in the greywater to be treated by EC. In terms of physical impurities, the results showed that the SF pretreatment step reduced the turbidity and the color of the treated GW by 28.4%, and 9.4%, respectively. The COD concentration was reduced by 25.5% by the SF step, which allowed a reduction of EC steady state time in the EC unit from 45 min to 30 min at an applied voltage of 15 V/cm. In addition, a high COD removal rate of 87.8% from high-load greywater was achieved with an energy consumption of only 4.11 kWh/m³ in comparison with 6.21 kWh/m³ without the SF step, which is equivalent to a 34% saving in energy consumption.

This study explores the electrocoagulation (EC) treatment of high-loaded gray water (HLGW), with the goal of optimizing operating parameters such as current densities (C _d) and EC time. Moreover, the research examines the kinetics involved in the removal of COD, color, and turbidity from HLGW. Various HLGW samples were treated at different current densities over a 90-min EC period. Kinetic analysis shows that COD removal follows a second-order model, while turbidity and color removal adhere to a pseudo-first-order model, with parameters dependent on C _d. The findings indicate that pollutant removal improves with longer EC treatment times and higher C _d values. At lower C _d levels, removal efficiencies for COD and color are relatively low, even with a 90-min EC treatment. However, at a higher C _d (20 mA/cm²), there is a substantial increase in removal efficiency, with 85% removal for both COD and color within the same duration. Turbidity is completely removed when the C _d is set to 10 mA/cm² after 45 min of EC treatment. These results highlight that achieving high pollutant removal from HLGW requires high energy consumption. As a result, combining EC with other processes, either as a pre-treatment or post-treatment step, may address the challenges faced by standalone EC systems. Using response surface methodology (RSM), optimal operating conditions were determined, achieving pollutant removals of 76.4% for COD, 80.5% for color, and 98.5% for turbidity, with a minimum energy consumption of 5.07 kWh/m³ at an EC time of 44 min and a C _d of 15.5 mA/cm².