| In recent years,with the rapid development of the global economy and the production industry,a great deal of wastewater containing heavy metal ions and dyes are discharged directly to environment,which makes the water environment continuously deteriorate and poses a serious threat to the ecosystem and human health.Therefore,it has important research significance how to efficiently,simply,economically and environmentally remove heavy metal ions and dyes from wastewater.In this study,based on the good biocompatibility and adsorption selectivity of?-cyclodextrin??-CD?,large specific surface area,magnetic responsiveness and biocompatibility of Fe3O4 magnetic nanoparticles,abundant oxygen-containing functional groups and large theoretical specific surface area of graphene oxide?GO?,an environmentally friendly,selective adsorption and magnetic separation?-cyclodextrin/Fe3O4/graphene oxide??-CD/Fe3O4/GO?magnetic nanocomposite was fabricated by a simple one-pot method and in-situ composite technology.The Pb???,Cu???and methylene blue?MB?were used as the target pollutants to study the adsorption properties of?-CD/Fe3O4/GO magnetic nanocomposite for metal ions and dyes.Using GO as carrier,ferrous sulfate heptahydrate?FeSO4·7H2O?and ferric chloride hexahydrate?FeCl3·6H2O?as precursors for the preparation of Fe3O4 magnetic nanoparticles,sodium hydroxide?NaOH?as precipitant,?-CD as modifier,?-CD/Fe3O4/GO magnetic nanocomposite was fabricated by a simple one-pot method and in-situ composite technology.The morphology,structure and performance of?-CD/Fe3O4/GO magnetic nanocomposite was characterized by transmission electron microscope?TEM?,scanning electron microscope?SEM?,X-ray diffraction?XRD?,Fourier transform infrared spectroscopy?FTIR?,thermogravimetric analysis?TGA?,vibrating sample magnetometer?VSM?,N2 adsorption/desorption isotherm,X-ray photoelectron spectroscopy?XPS?and Zeta potential analysis.The adsorption properties of?-CD/Fe3O4/GO magnetic nanocomposite for Pb???,Cu???and MB in single aqueous solution were explored by batch experiments.The effects of initial Pb???,Cu???and MB concentration,solution pH value and contact time on the adsorption property of?-CD/Fe3O4/GO nanocomposite was investigated in details.Simultaneously,the pseudo-first-order,pseudo-second order and intra-particle diffusion kinetic models were employed to study the adsorption kinetics,the Langmuir and Freundlich isotherm models were used to evaluate the isothermal adsorption process,the adsorption mechanisms were also investigated.The results showed that the superparamagnetic?-CD/Fe3O4/GO nanocomposite was successfully fabricated.The specific saturation magnetization of?-CD/Fe3O4/GO nanocomposite was 10.69emu·g-1,which can meet the magnetic separation requirements.The maximum adsorption capacities of?-CD/Fe3O4/GO nanocomposite for Pb???,Cu???and MB were 279.21,51.29 and 93.97 mg·g-1 at 298 K,respectively.The adsorption process could be better fitted by pseudo-second-order model and Langmuir model.The adsorption process was mainly considered as a monolayer chemical adsorption. |
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