Silica-Supported Alginates From Djiboutian Seaweed as Biomass-Derived Materials for Efficient Adsorption of Ni(II)

Abstract

International audienceThe development of environmentally friendly, reusable and highly performant adsorbent materials for the removal of heavymetal ions is a big challenge in the field of wastewater treatment. Therefore, in this study, ecofriendly composite materialsbased on alginates extracted from Sargassum sp (Alg.S) and Turbunaria (Alg.T) and supported on different silica parti-cles were prepared and used as adsorbents for Ni(II) ions removal from aqueous solutions. These composites efficientlyextract Ni(II) ions, i.e. the optimal adsorption amount of Ni 2+ reaches 251 mg.g−1 at pH 5 for one composite, surpassingthe adsorption capacities of other adsorbents reported so far in the literature. The kinetic data fit well with a pseudo-secondorder model. Furthermore, the adsorption in a binary system containing both Ni(II) and Pb(II) was also studied. The effectof pH, concentration, and other parameters on the adsorption capacity as well as on kinetics were systematically examined.These results demonstrate that ours composites show great potential as low-cost bio-adsorbents to remove Ni(II) ions fromaqueous solutions