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• Concentration electrodialysis (CED) was developed by combining ED and DD. • CED was used to selectively remove NH 4 +-N from high-salinity wastewater. • CED improved 32.3% and 13.3% removal rates compared to ED and DD, respectively. • CED reduced 14 h and 10 h to achieve the same removal percentages as ED and DD. • CED increased the current efficiency by 1.84 times compared with ED. In this study, a novel method, concentration electrodialysis (CED), was developed by combining conventional electrodialysis (ED) and Donnan dialysis (DD) effectively and selectively to separate NH 4 +-N from high-salinity wastewater. A high initial concentration of Na+ was provided in the cathode compartment to impede its competitive migration with NH 4 +. After optimization, the CED process removed up to 89.1% of NH 4 +-N from simulated high-salinity wastewater with an energy consumption of 0.51 × 10−3 KWh·mol−1. The initial brine concentration was the limiting factor for the removal percentage and rate. The maximum removal percentage was 13.3% and 32.3% higher than those of conventional ED and DD, respectively. CED shortened the time required to achieve the same final removal percentages achieved by conventional ED and DD by 14 h and 10 h, respectively. In addition, the current efficiency of CED was increased by 1.84 times greater than that of conventional ED, while reduced 50.48% of energy consumption. Moreover, the Na+ concentrations in the cathode and wastewater compartments both remained relatively constant, indicating that there was no need to add additional Na+ during the experimental process, which was beneficial for prolonging the experiment and reducing cost. Finally, the performance of CED in removing NH 4 +-N from actual maricultural wastewater further supported its potential for application in the future. [ABSTRACT FROM AUTHOR]