Evaluation of a continuous flow electrocoagulation reactor for turbidity removal from surface water

The objective of this research was to evaluate the performance of a continuous electrocoagulation (EC) reactor for treating surface waters with high turbidity levels. The reactor design consisted of 20 interconnected channels arranged in series, resulting in an effective treatment volume of 8.7 L. The results showed that increasing the flow rate, voltage, and operating time improved turbidity removal. However, high initial turbidity levels had a negative impact on removal. In the continuous EC test, synthetic water containing kaolin with an initial turbidity of 150 NTU was treated at a flow rate of 300 mL.min−1 and a voltage of 30 V for 30 min. This configuration achieved a turbidity removal efficiency of 97.26%. However, the treated water exhibited an increase in aluminum concentration from 5.881 mg.L−1 to 6.871 mg.L−1, exceeding the limits set by the World Health Organization (WHO). This unfavorable consequence was attributed to the release of aluminum metal ions during the inherent electrolytic oxidation process in EC. Furthermore, an economic analysis showed that the operating costs for continuous operation amounted to 0.087 USD.m−3, demonstrating the economic viability of implementing the continuous EC reactor on a larger scale. © 2023 Institution of Chemical Engineers