Abstract
Sodium alginate was protonated using HCl in ethanol: H2O mixture (30:70). The modified sodium alginate (MSA) was characterized by determination of carboxyl content and solubility percent. The modified sample acquires of 450 meq-COOH/100 g sample and exhibits the complete insolubility in water. The MSA was utilized as adsorbent material to remove Cd(II) ions from aqueous solutions. Factors affecting adsorption process, such as agitation time and adsorbent concentration and pH of the adsorbate, were examined. The adsorption data show that the maximum adsorption capacity, Qmax, of Cd(II) onto MSA is 769.23 mg/g. The adsorption data also showed that the adsorption of Cd(II) onto MSA obeys Langmuir and Freundlich isotherms.