Capacitive deionization for water desalination: Optimizing operational parameters and validating the model across concentrations variant

Researchers have widely explored capacitive deionization (CDI) for brackish water desalination over the last decade, considering it a promising technology. Theoretical and statistical analyses are crucial for optimizing CDI performance parameters. This study utilizes response surface methodology (RSM) with central composite design (CCD) to systematically explore the impacts of crucial operational variables on CDI efficiency. Our analysis yielded a robust quadratic model with a high R-squared value (0.99), indicating excellent predictive capability. The CDI performance was conducted using activated carbon cloth electrodes and achieved a maximum removal efficiency of 40.6 % under optimal conditions of 1.8 DC V, 2 ml/min, and 500 mg/L NaCl. The increase in applied potential enhanced removal efficiency, whereas flow rate and NaCl concentration had adverse effects. The validity of the resulting model was further tested with various water sources such as groundwater and produced water, demonstrating its predictive capability when a pretreatment step is included. However, we recommend developing a new model for more robust optimization of CDI systems.