A statistical experimental investigation on arsenic removal using capacitive deionization

In this study, arsenic removal from water by a solar-powered capacitive deionization (CDI) unit was investigated. The Box–Behnken statistical experiment design (BBD) as an example of response surface methodology was used to investigate the effects of major process parameters. Initial arsenic concentration, pH, and background sodium chloride concentration were selected as independent variables in BBD, while arsenic removal was considered as the response function. The predicted values of arsenic removal obtained using the response functions were in good agreement with the experimental data. The current CDI technology was found to be an effective and reliable alternative for arsenic removal from water with higher than 80% removal achieved in all designated experiments. In general, CDI removal of arsenate ions favors higher pH and lower salinity conditions. This study showed that BBD methodology was an efficient and feasible approach in predicting the effects of different experimental conditions during an arsenate removal process by CDI.