This paper discusses the removal of ammonium ions (NH₄)⁺ from raw water using a hydrogel as an adsorbent. The raw water has been obtained from Fesha water treatment plant which is a traditional treatment plant located in Behera. For this purpose, kappa carrageenan/acrylic acid hydrogel (KC/AAc) were prepared via free radical polymerization using gamma irradiation. The effect of irradiation dose and (AAc) concentration on gel content was studied. The formed hydrogel was characterized by FTIR and SEM. The swelling behavior was determined as a function of irradiation dose, and AAc content. The developed hydrogel was used for the removal of (NH₄)⁺ ions. The effects of various operating parameters such as initial pH, contact time, and adsorbent dose on the removal of (NH₄)⁺ ions have been investigated. It was found that the optimum pH value is 5 and the perfect adsorbent dose is 15 gm/L. A fast adsorption rate was observed the equilibrium was reached within 50 min and the maximum removal percent was (52.7%).