The breakthrough curves for adsorption of monovalent phosphate anions on ammonium-functionalized MCM-48 adsorbent were investigated in a packed-bed column under different operating conditions. The obtained results proved the technical feasibility of such a system to remove phosphate anions. The breakthrough curves denoted a sharp S-shape influenced by inlet concentrations, flow rate, and bed depth. The breakthrough times decreased with an increase in the inlet concentration and flow rate and increased with an increase in the bed depth. A mathematical model taking into account the different transport phenomena occurring in a packed bed column was developed and applied successfully to the experimental breakthrough data using the Ogata-Banks analytical solution.