Synthesis Of Magnetic Nano-composite And Its Adsorption Of Uranyl Ions

Based on its advantage of reliable, efficient, green and safety, nuclear power industry become the strategic choice of the respective countries to respond to climate issues and fossil energy shortage of which technology its mature. But nuclear power production process including mining, processing, separation and purification of nuclear fuel and reactor operation produces a large amount of radioactive uranium waste that can cause damage to health ane social-economic development with radioactive toxic and chemical toxic, environmental costs of uranium mining is increasing. So exploitation of efficient technologies for dealing with uranium-containing wastewater is significant to protection of environment.In a variety of uranium-containing wastewater processing techniques, adsorption became the focus of research for advantages of simple and convenient, wide source, high efficiency and low cost. Nevertheless selection and preparation of efficient functional adsorbent became the focal point. Compared with conventional adsorption material, magnetic nano-materials have advantages of remarkable nano-size effect, high surface activity, easy solid-liquid separation, etc. Modification of the materials' surface effectively to inhibit reunion and enhance the selective adsorption performance and stability has become the hot topics of magnetic nano-adsorbent.Based on the above background, this paper focuses on synthesis of functional magnetic nano-adsorbent and study of is adsorption properties of uranyl ions, the main contents and conclusions are as follows:1 Firstly we synthesised magnetic nanoparticles by co-precipitation method, then used embedded surface modification methods to obtain composite nano-adsorbent by the reaction among magnetic nanoparticles, tetraethyl orthosilicate and 3-aminopropyltriethoxysilane, which were characterized by Fourier Transform Infrared Spectoscopy(FTIR), Scanning electron microscopy(SEM), Thermal Gravimetric Analyzer(TGA), X-ray diffraction(XRD). The adsorption abilities and mechanisms of the new adsorbent for the uranyl ions were studied through a series of adsorption experiments and mathematical models. The results indicate that this compound adsorbent is efficient for the removal of uranyl ions with the following conclusions:(1)Composite magnetic nanoparticles-adsorbent has fluffy surface, uniform size, and the average particle size is about 100 nm.(2)EPPTMS-MN exhibited excellent adsorption properties for uranyl, in the condition of p H=6, T=30?, t=1h, the optimum adsorption efficiency value was 97.6 % for 20 mg/L solution of uranyl, and the value was over 98% for the Low concentration uranyl solution. According to the mathematical model analysis, we can see EPPTMS-MN adsorption process of uranyl using EPPTMS-MN is a monolayer-based chemical adsorption process, combined with multilayer adsorption and pore diffusion.(3)The method has advantages of easy operation, fast and efficient, easy to separate, low cost and no secondary pollution, etc, which can be used in nuclear waste's disposal.2 We synthesized supramolecular calixarene derivative with property of recognizing uranyl, and attempts to graft it onto EPPTMS-MN surface chemically to obtain calixarene functionalized magnetic nano-adsorbent and test its adsorption properties of uranyl.(The experiment only gets preliminary progress.)...