Alginate modified graphene oxide for rapid and effective sorption of some heavy metal ions from an aqueous solution

Abstract

Herein, we investigated a new strategy to modify the graphene oxide (GO) with sodium alginate (SA) using tetraethylorthosilicate (TEOS) as a binding agent. The graphene oxide-sodium alginate composite was highly loaded with carboxylate (–COO−Na+) groups, which permitted fast and efficient interaction with the metal ions. Therefore, the prepared composite was employed as an efficient adsorbent to uptake some heavy metals from an aqueous solution. The as-synthesized GO-SA was characterized by various advanced techniques before and after the removal process. The analysis of the experimental data showed that the Langmuir model fits well the adsorption data with maximum adsorption capacities of 887.21, 161.25, and 139.62 mg g−1 for Pb2+, Zn2+, and Cd2+, respectively. Moreover, the GO-SA presented a good regeneration and reuse ability, enhancing the removal rate for all the studied metal ions. In addition, the prepared composite showed a suitable selectivity for Pb2+ from Zn2+, and Cd2+ co-existed solution.