Electrocoagulation efficiency probed using electrochemical impedance spectroscopy

In order to treat the polluted discharge from El-Jadida, Morocco, a method of electrocoagulation using aluminum electrodes was used. This approach was coupled for the first time with high-frequency electrochemical impedance spectroscopy (EIS). Significant pollutant abatement was observed after 30 min, at a current density of 190.5 A center dot m-2, with a specific electrical energy consumption of 1.58 kW center dot h (per gram of eliminated carbon organic demand (COD)) and specific aluminum consumption of 0.11 g center dot g-1: electrocoagulation proved to be particularly effective, achieving 85.7% elimination of COD and a decrease of total dissolved solid (TDS) and electrical conductivity (EC) levels from 2430 mg center dot L-1 to 1773 mg center dot L-1 and from 4230 m S center dot cm-1 to 3210 m S center dot cm-1 , respectively. As for USP and ORP, they decreased from 2.5 to 1.87 and from 244.6 mV to 51 mV, respectively. The inductance of the electrocoagulation system measured by EIS was modeled through an electrical equivalent circuit. When the applied intensity increased, the coagulation resistance increased suddenly when the applied electrical current reached 0.2 A (current density: 95.2 A center dot m-2). At this point, the rate of COD abatement versus SEEC (specific electrical energy consumption decreases which shows that the EC process should be combined with another process to improve its efficiency, such as ultrasound. (c) 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.