| As the over-speed economic developping, enviromental problems, including water pollution, rubbish, waste water, greenhouse gases, have threatened human’s health. Among them, industrial effluent is an urgent issue owing to its difficult degradation and random emission. The industrial effluent contains organic compound, dyes, pigment, heavy metal (Pb, Hg, Cr etc) and suspended solid. All of them would affect human’s health once they are not controlled and managed effectively.Magnetic nanomaterials have attracted numerous attentions because of their good magnetic responsiveness, various morphology, larger specific surface area and so on. Moreover, we also could modify this material to broaden its applications. Traditional absorption materials and catalytic materials would flow away during the reaction process and they are difficult to retrieve. Fortunately, the emerging magnetic separation technology may solve the above problems. This novel technology could largely become an effective, simple way to purify waste water. Therefore, we are proposed to synthesize a series of novel nanomaterials which reveal uniform size, various morphology and high performance.1. Synthesis of flower-like magnetic adsorbents (FMAs) and the heavy metal ions in waste water.In this chapter, we synthesized FMAs via one-step method and confirmed their formation mechanism. In addition, FAMs were characterized by TEM, SEM, XRD and BET. EAMs own higher specific surface area (71.6 m2/g), large saturated magnetic values (44.41 emu/g), abundant of functional groups and so on. We also searched the absorption capacity on methylene blue, malachite green, Pd+ and Cr+ detailed. Besides, the adsorption kinetic and adsorption isotherms was also discussed.The simultaneous adsorption of the FAMs for MG and Pb2+was determined in a binary system. The results suggest that FAMs exhibited excellent absorption capacity.2. Synthesis of core-shell nanomagnetic iron-based catalyst and its application in Fenton-like reaction.We developed a highly efficient method for preparation of core-shell iron oxides nanoparticles (FexOytgFexOy/C) via a solvothermal reaction and annealing method. The overall procedure does not require complicated steps. Core-shell FexOy@FexOy/C possesses enhanced surface area and surface energy relative to the precursor due to the core-shell structure, which provided a double face (the core and shell composed of active components) to contact with reactants. Furthermore, zero-valent iron (Fe0)-iron oxides nanocomposites is formed in the core and shell by in situ reduction in high-temperature calcination process, the electron transfer of Fe0 with Fe3+species from the oxides during the reaction can regenerate the Fe2+(in iron oxides) which are the active species for the Fenton reaction. Thus, improved catalytic performances could be expected on such core-shell FexOy@FxOy/C. As a proof of concept study, methylene blue (MB) was selected as the model pollutant for economic evaluation of Fenton process using the core-shell FexOy@FexOy/C nanoparticles. The results show that the FexOy@FexOy/C nanoparticles exhibits a significantly higher catalytic activity and stability, while some disadvantages from the conventional homogeneous/heterogeneous Fenton-like catalysts are nearly nonexistent. |
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