Novel graphene oxide based adsorbents for removing water pollutants Pb2+, Cd2+, Mn2+, and Mg2+ ions

Novel adsorbent is prepared by modifying graphene oxide/sodium alginate with disodium ethylenediaminetetraacetate (SGE). Benefiting from the network-alike structure, and the abundant hydroxyl and amino groups, the removal of SGE for Pb2+, Cd2+, Mn2+, and Mg2+ ions from water is effective and fast at neutral pH values. The adsorption equilibrium of SGE for Pb2+, Cd2+, Mn2+, and Mg2+ ions can be well-modeled with the Langmuir isotherm. The adsorption processes of Pb2+, Cd2+, Mn2+, and Mg2+ ions onto SGE are shown to follow the kinetics of pseudo-second-order reactions. The maximum adsorption capacities for Pb2+, Cd2+, Mn2+, and Mg2+ ions are 121.2, 117.1, 56.7, and 41.8 mg/g at 298 K, respectively. The desorption and regeneration experiments show that the respective adsorption capabilities for Pb2+, Cd2+, Mn2+, and Mg2+ are approximately 92.8%, 91.1%, 89%, and 85.7% after the 5th cycle. These results demonstrate that SGE composite is a promising adsorbent for the treatment of wastewater heavy metal ions.