A systematic review and statistical analysis of nutrient recovery from municipal wastewater by electrodialysis

These days electrodialysis is recognized as a promising process for the removal and recovery of nutrients from wastewater. However, the electrodialysis process for nutrient recovery is different from traditional desalination electrodialysis, and limited knowledge exists regarding its new application. Therefore, a comprehensive review and critical comparison of the different parameters and optimal operation conditions for nutrient recovery by electrodialysis in various studies are discussed in this manuscript. The relationship between the nutrient recovery rate and critical operating parameters such as voltage, the total effective area of the membrane, number of cell pairs, and feed composition in various wastewater sources is statistically analyzed. Regression results showed that increasing voltages, membrane, and cell numbers improved the recovery rate, respectively. However, it should be mentioned that different mobility behavior of ions are influenced by an electric double layer, selectivity, repulsion of the ion-exchange membrane, and operation conditions including voltage, current density, operation time, and ion concentrations. Hybrid processes enhance the electrodialysis efficiency in wastewater by increasing the feed concentration. The capital and operating costs of the electrodialysis process can be significantly affected by the pump, electrode, and ion-exchange membrane characteristics. Fouling and scaling as a challenge in electrodialysis are investigated in our study.