Synthesis of magnetic UiO-66-NH2@EDTA-GO and mechanism study of simultaneous adsorption of Pb(ii) and organic dyes from water

Abstract

Heavy metal ions and organic dyes are some of the main pollutants in water environments, which have the potential to cause harm to the ecological environment and human health. Although adsorption technology has been widely used in the treatment of pollutants in water, the selection of adsorbents is still a challenge considering the adsorption capacity and regeneration ability of the adsorbents. This article reports a new type of composite nanomaterial Fe₃O₄/UiO-66-NH₂@EDTA-GO with magnetic and highly structured pore channels. The composite material is composed of Fe₃O₄, UiO-66-NH₂, and functionalized graphene oxide, which has the advantages of magnetic recovery, high surface area, and well-developed porous structure. The adsorption behavior of the target pollutants on Fe₃O₄/UiO-66-NH₂@EDTA-GO was investigated by batch adsorption experiments. The experimental results show that when the initial concentration of the target pollutants is 100 mg L⁻¹, the temperature is 293 K, and the solution pH is 6, the adsorption capacity of Pb(II) reaches 82.81 mg g⁻¹ after 60 min of adsorption, the adsorption capacity of methyl orange (MO) reaches 61.08 mg g⁻¹ after 30 min of adsorption, and the adsorption capacity of methylene blue (MB) reaches 86.48 mg g⁻¹ after 60 min of adsorption. This experiment also studied the adsorption capacity of Fe₃O₄/UiO-66-NH₂@EDTA-GO for organic–inorganic binary composite pollutants and the interaction between different pollutants in the composite pollution system. The results show that the composite material has efficient adsorption capacity for different types of pollutants. The component analysis of the samples before and after adsorption was carried out by XPS, and Fe₃O₄/UiO-66-NH₂@EDTA-GO has different adsorption mechanisms for different types of pollutants. This study provides a foundation for the application of new composite materials, which has important scientific and practical significance.