Abstract In this study, the peroxi-electrocoagulation process was investigated for the treatment of pistachio processing wastewater. The electrolysis cell was configured with 5 × 5 iron plate electrodes at a fixed 5 mm spacing. Electrolysis time of 90 min, 25 °C temperature, and 200 rpm stirring speed were maintained constant throughout the experiments. The effects of H 2 O 2 dose (94–658 mM), initial pH (2. 0–6. 0), and current density (1–6 mA/cm 2) on the removal of TOC, COD, and total phenol (TPh) were evaluated. Optimum operation conditions within the studied range were found as 564 mM H 2 O 2, 3. 0 initial pH, 3 mA/cm 2 current density, resulting in 88. 9% TPh, 80. 7% COD, and 65% TOC removal efficiencies. Kinetic study showed that the PEC process followed second-order kinetics, with R 2 of 0. 82, 0. 82, and 0. 80 for TPh, COD, and TOC, respectively. Reaction rate constants increased with increasing current density and H 2 O 2 concentration, whereas reaction rates decreased at pH below and above 3. 0. The highest reaction rates were observed at pH 3. 0, 6 mA/cm 2 CD, and 658 mM H 2 O 2. A single hidden-layer backpropagation network with a topology of 4: 6: 3 was developed following hidden layer neurons optimization to predict TOC, COD, and TPh concentrations. The final ANN model performance yielded RMSE of 150. 4 ± 31, 725. 7. 3 ± 156. 9, and 197. 2 ± 37. 9, and R 2 of 0. 98, 0. 97, and 0. 95 for TPh, COD, and TOC, respectively. The high correlation between measured and predicted concentrations (R 2 ; TPh: 0. 97, COD: 0. 97, TOC: 0. 92), confirmed the reliability of the model. Under selected conditions, the specific energy consumption and operating cost were calculated as 16. 2 kWh/kg COD and 65. 9 /m 3, respectively. Graphical Abstract
Bayar et al. (Fri,) studied this question.