Thiol Modified Magnetic Fe₃O₄ Nanoparticles For Uranium Adsorption

Radioactive metal pollution such as uranium ions contamination has become an serious global problems increasingly.Without effective treatment of wastewater containing uranium will not only pollute the environment but also harm to the natural biological and human health,on the one hand is radioactive hazard,natural uranium has radiation on plants and animals and human cells have a strong sense of destructive.On the other hand is a chemical toxic hazards,also belong to heavy metal uranium can combined with proteins,leading to changes in the structure of the protein irreversibly,make tissue cell function disorder,endangering life health.There are a lot of methods for recovery or removal of radioactive metal contamination from aqueous solutions.Sorption is commonly used for the waste water purification because of its low energy consumption,ease of handling,and capably handle a wide range concentration poisonous metal waste water.Despite of the prior performance,the research on sorption still faced with challenges that the separation and recycling of adsorbents.Thus,the key to solve this problem is to find a new type of adsorbent both of safety and efficiency.By optimizing the experimental conditions,this paper adopts the method of modified St?ber with the control of the silane modifier dosage and reaction time make Fe₃O₄ nano ball surface with a layer of SiO₂ get Fe₃O₄@SiO₂ microspheres;adopts the MPTES to modified the magnetic Fe₃O₄ nano with thiol groups get Fe₃O₄@SiO₂–SH magnetic adsorption material.FTIR spectra confirms that the surface of the Fe₃O₄ inorganic particles in tandem with SiO₂ and the thiol groups.The size of modification magnetic particles Fe₃O₄@SiO₂ and Fe₃O₄@SiO₂–SH are slightly increased.with laser particle size analyzer to determine Fe₃O₄@SiO₂ and Fe₃O₄@SiO₂–SH in the water of the particle size distribution,particle size of Fe₃O₄@SiO₂ is 45–70 nm,particle size of Fe₃O₄@SiO₂–SH is about 50–80 nm.Vibrating sample magnetometer?VSM?results showed that saturation magnetization?Ms?of modification Fe₃O₄ magnetic particles,although a slight decline,but they have superparamagnetism.The saturation magnetization of Fe₃O₄@SiO₂ is49.72emu/g,the saturation magnetization of Fe₃O₄@SiO₂–SH is 52.37emu/g,better retain the original magnetic characteristics.Applies two kinds of magnetic adsorbent to adsorb the uranium ions from aqueous solution.investigate the adsorption performance and the influence factors of research.The results indicate that:pH value of the uranium ions solution has a great influence on the effect of adsorption,adsorption effect is best when p H=5.5;Adsorption reaction after 3h basic balance.With the increase of solution concentration,carrier adsorption volume is increasing,the experimental temperature and concentrations of adsorption isotherm in line accord with the Langmuir monolayer adsorption model.Modification of thiol Fe₃O₄@SiO₂-SH adsorption ability of Fe₃O₄@SiO₂ more than twice.At 298K,the saturated adsorption amount of Fe₃O₄@SiO₂–SH to UO₂²⁺is 89.05 mg/g,the saturated adsorption amount of Fe₃O₄@SiO₂ to UO₂²⁺is 34.95 mg/g.At room temperature,the adsorption of U???for Fe₃O₄@SiO₂–SH conforms to the Pseudo-first-order kinetics model.Use of the dilute hydrochloric acid to handle the post-use Fe₃O₄@SiO₂ and Fe₃O₄@SiO₂–SHmaketheUO₂²⁺desorption.Post-processing Fe₃O₄@SiO₂ and Fe₃O₄@SiO₂–SH can be reused.