الفهرس 
Water pollutantsOnly 14 pages are availabe for public view
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Abstract
To improve the efficiency and selectivity of ammonia (NH4
+) removal from wastewater. The most efficient method for eliminating NH4
+ from wastewater through a coordinated complexation is ligand exchange. In this work, two strong acidic resins,Amberlite IR-120 (R-H) and Dowex-50WX8 (D-H) were loaded with transition metal cations such as, Cu(II), Ni(II), and Co(II) using the impregnation method. Various techniques, such as FT-IR, TGA, SEM, and EDX, were used to characterize the prepared R-Cu2+ and D-Cu2+. The synthesized R-Cu2+ and D-Cu2+ were applied to remove NH
+ from an aqueous solution. The effect of loaded counter cations on the NH4
+ removal percentage was examined.The results showed that, NH4
+ removal percentage followed the order; the loaded resin with Cu2+ > Ni2+ > Co2+ for both R-H and D-H. The effects of contact time, pH, initial concentration, temperature, and coexisting ions on the removal of NH4
+ from wastewater by R-Cu2+ and D-Cu2+ were investigated. Ammonia adsorption
kinetics onto R-Cu2+ and D-Cu2+ matched to the pseudo 2nd order model during
the chemisorption process. According to the isotherm adsorption models, the nonlinear plot of the Freundlich and Langmuir isotherms is consistent for the NH4
+ adsorption onto R-Cu2+. However, the non-linear Langmuir fitted for the
adsorption using D-Cu2+. On using R-Cu2+ and D-Cu2+, the maximum adsorption efficiency of NH4
+ was 200 and 280.9 mg/g, respectively. Thermodynamic characteristics showed that the NH4
+ adsorption onto R-Cu2+ was endothermi.However, the adsorption onto D-Cu2+ was an exothermic reaction. The removal mechanism of NH4
+ proposed through the two processes, one is the ion exchange between hydrogen ions of polymeric resins and NH4
+. The other is the complexation between Cu2+ ions loaded onto chelating resins and ammonia.However, complexation via ligand exchange technology is the most popular mechanism. Moreover, the resulting products (R-Cu(II)-ammine and D-Cu(II)- ammine composites) from the NH4
+ adsorption process, exhibited high catalytic