Extracting valuable products from wastewaters with nitrogen-selective adsorbentsc an offset energy-intensive ammonia production, rebalance the nitrogen cycle, and incentivize environmental remediation. Separating nitrogen (N) as ammoniumf rom other wastewater cations (e.g.,K + , Ca 2 +)p resents am ajor challenge to Nr emovalf rom wastewater and Nr ecoverya sh igh-purityp roducts. High selectivity and capacity were achieved through ligand exchange of ammonia with ammine-complexing transition metalsl oaded onto polymeric cation exchange resins. Compared to commercial resins,m etal-ligande xchange adsorbents exhibited higher ammonia removalc apacity (8 mequivg À1)a nd selectivity (N/K + equilibrium selectivity of 10.1) in binary equimolar solutions. Considering optimal ammonia concentrations (200-300mequivL À1)a nd pH (9-10) for metal-ligand exchange, hydrolyzed urine wasi dentified as ap romising candidate for selectiveT AN recovery.H owever,d ivalent cation exchange increased transition metal elutiona nd reduced ammonia adsorption.U ltimately,m etal-ligand exchange adsorbents can advance nitrogen-selective separations from wastewaters.