From thedata obtained (Fig. 4), the amount of metal uptake by the hydro-gel increased with decrement of acidity of the aqueous solution.The optimum pH for Pb ions was pH 4, while for Cu and Cd ionswere pH 5, with the amount of metal uptake were 93.43%, 63.19%and 52.51%, respectively. The ionic interaction between the nega-tive charge in carboxymethyl group in the hydrogel and positivecharge of metal ions become the main factor of the removal metalions from the aqueous solution