The electrocoagulation process was employed for the removal of organic and inorganic contaminates from synthetic wastewater and domestic wastewater. A four-electrode configuration powered by a DC supply was used for wastewater treatment, with the monopolar system electrode sequentially alternated across the reactor. In this work, four electrode electrocoagulation system with Al/Cu electrode were investigated for synthetic and real wastewater treatment: Homogeneous, heterogeneous, and reverse heterogeneous electrode configuration. The results indicated that aluminium rich homogeneous and reverse heterogeneous configurations system achieved higher removal efficiencies, particularly for Pb(II) and Cd(II), while copper-rich systems influenced Cr(VI) removal via redox interactions and sludge characteristics. The heterogeneous electrode configuration, achieving low energy consumption (50.78 kWh m− 3) and minimal electrode dissolution (2.86 g L− 1) with excellent removal efficiencies (Pb(II) 98.88 ± 1.50%, Cr(VI) 98.81 ± 1.5%, Cd(II) 99.92 ± 1.0%). Although reverse heterogeneous showed similarly higher heavy metals removal, it incurred higher energy consumption due to pH-driven hydroxide precipitation. Based on best performance of the heterogeneous configuration applied to the real domestic wastewater, the process achieved reduction in BOD from 312 to 54 mg/L and COD from 352 to 112 mg/L. Additionally, an increase in pH from 7.2 to 8.8 was observed; this rise in pH is consistent with the generation of hydroxyl ions at the cathode. Under these conditions, the energy consumption was 37.92–50.78 kWh/m3, and the total estimated treatment cost was approximately 7.4–8.8 USD/m3. On the other hand, the influence of sludge formation under homogeneous and heterogeneous electrode hybrid configurations was evaluated using FESEM, X-ray diffraction (XRD), and EDX analyses. Homogeneous produced voluminous Al(OH)3-rich flocs suitable for broad coagulation, whereas copper rich homogeneous generated compact Cu(OH)2 sludge with higher selectivity toward Pb(II) and Cr(VI). Heterogeneous electrode hybrid configurations, particularly heterogeneous, showed a synergistic balance that enabled effective contaminant removal with reduced sludge generation. Overall, sludge characterization confirms that electrode material and configuration strongly governs energy consumption, underscoring the significance of electrode architecture in optimizing energy, and identifying the optimum electrode arrangement to facilitate large-scale industrial implementation of EC systems. Graphical abstract

Wastewater treatment using electrocoagulation: performance evaluation of monopolar hybrid electrode configurations

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发表日期：

2026年6月18日

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Rakhi Baghel,
Anurag Kumar Tiwari,
N. K. Srivastava

摘要

The electrocoagulation process was employed for the removal of organic and inorganic contaminates from synthetic wastewater and domestic wastewater. A four-electrode configuration powered by a DC supply was used for wastewater treatment, with the monopolar system electrode sequentially alternated across the reactor. In this work, four electrode electrocoagulation system with Al/Cu electrode were investigated for synthetic and real wastewater treatment: Homogeneous, heterogeneous, and reverse heterogeneous electrode configuration. The results indicated that aluminium rich homogeneous and reverse heterogeneous configurations system achieved higher removal efficiencies, particularly for Pb(II) and Cd(II), while copper-rich systems influenced Cr(VI) removal via redox interactions and sludge characteristics. The heterogeneous electrode configuration, achieving low energy consumption (50.78 kWh m^{− 3}) and minimal electrode dissolution (2.86 g L^{− 1}) with excellent removal efficiencies (Pb(II) 98.88 ± 1.50%, Cr(VI) 98.81 ± 1.5%, Cd(II) 99.92 ± 1.0%). Although reverse heterogeneous showed similarly higher heavy metals removal, it incurred higher energy consumption due to pH-driven hydroxide precipitation. Based on best performance of the heterogeneous configuration applied to the real domestic wastewater, the process achieved reduction in BOD from 312 to 54 mg/L and COD from 352 to 112 mg/L. Additionally, an increase in pH from 7.2 to 8.8 was observed; this rise in pH is consistent with the generation of hydroxyl ions at the cathode. Under these conditions, the energy consumption was 37.92–50.78 kWh/m³, and the total estimated treatment cost was approximately 7.4–8.8 USD/m³. On the other hand, the influence of sludge formation under homogeneous and heterogeneous electrode hybrid configurations was evaluated using FESEM, X-ray diffraction (XRD), and EDX analyses. Homogeneous produced voluminous Al(OH)₃-rich flocs suitable for broad coagulation, whereas copper rich homogeneous generated compact Cu(OH)₂ sludge with higher selectivity toward Pb(II) and Cr(VI). Heterogeneous electrode hybrid configurations, particularly heterogeneous, showed a synergistic balance that enabled effective contaminant removal with reduced sludge generation. Overall, sludge characterization confirms that electrode material and configuration strongly governs energy consumption, underscoring the significance of electrode architecture in optimizing energy, and identifying the optimum electrode arrangement to facilitate large-scale industrial implementation of EC systems.

Graphical abstract