Adsorption of Ni(II) and Cd(II) from Aqueous Solutions Using Modified Rice Husk

Background and purpose: recently, release of pollutants such as heavy metal ions to theenvironment becomes one of the most important problems for soil and water. the present studywas conducted to introduce modified rice husk (rh) as a new low-cost adsorbent.materials and methods: in this study, tartaric acid modified rh (tarh), was used as anadsorbent for removal of ni(ii) and cd(ii) from water samples. this study was conducted inlaboratory scale. employing batch method, solution ph, adsorbent dose, contact time, and initialmetals concentration were optimized.results: the optimum ph for removing of both the investigated metal ions from water solutionswas found to be 4.0. the process of ni(ii) and cd(ii) adsorption on tarh reached equilibriumwithin 45 min. the isotherm evaluations revealed that the langmuir model attained better fits ofthe experimental equilibrium data than the freundlich model. in addition, adsorption kineticsdata were well-fitted by the pseudo-second-order rate model with high regression coefficients.conclusion: it was found that tarh is a highly efficient adsorbent for ni and cd from aqueoussolution, and the maximum predicted adsorption capacities for ni(ii) and cd(ii) were obtained as55.5 and 45.5 mg/g, respectively.