A facile composite material for enhanced cadmium(II) ion capturing from wastewater

Abstract

Cadmium (Cd(II)) ion is one of the most important toxic metals to remove from contaminated water for safe-guarding the public health. Elevated levels of Cd(II) ion in natural water may have a detrimental effect on both human health, environment and the eco-system. The functionalized materials have been investigated widely over the years for numerous uses to exert a considerable technological impact on future miniaturized, compact, cost effective, and efficient devices. From this point of view, the functional ligand based composite material was fabricated based on the direct anchoring methods for effective Cd(II) ion detection and removal from wastewater. The significant color was visualized upon addition of Cd(II) ion at optimum condition. The optimum pH was carefully evaluated, and pH 5.50 was selected based on the sensitivity, selectivity and color formation. The detection limit was 0.37 μg/L, which was lower than the permissible limit of Cd(II) ion in water. The variable experimental parameters such as solution pH, initial concentration, contact time and foreign ions were systematically evaluated both in monitoring and adsorption operations. The adsorption data were well fitted to the Langmuir adsorption model, and the maximum adsorption capacity was 186.36 mg/g. In the presence of competing ions, the Cd(II) detection and adsorption were not affected due to the specific binding affinity between the composite material and Cd(II) ions. The adsorb Cd(II) ion was desorbed from the composite material using 0.15 M HCl, and the material were simultaneously regenerated into the initial form for the next cycle use without loss the functionality.