(东华理工大学 核资源与环境国家重点实验室，南昌 330013)
摘 要: 以液相还原法制备纳米零价铁，将其负载于石墨表面制备负载型纳米零价铁复合材料(G-nZVI)，并用来去除溶液中的U(Ⅵ)，考察初始溶液的pH、反应温度、反应时间、U(Ⅵ)的初始浓度以及固液比等因素对复合材料(G-nZVI)去除U(Ⅵ)影响。用扫描电镜(SEM)和X射线衍射(XRD)技术对反应前后的材料进行表征，分析其去除U(Ⅵ)的机理。结果表明：纳米零价铁颗粒分散在石墨粉的表面，没有产生团聚。反应后溶液中主要生成UO2和U(Ⅳ)氢氧化物沉淀。石墨负载型纳米零价铁对U(Ⅵ)有很好的去除效果，在pH为4.0，温度为30 ℃，反应时间为60 min，固液比为0.25 g/L，初始U(Ⅵ)浓度为10 mg/L条件下，U(Ⅵ)的去除率和吸附容量分别达到99.67%和43.2 mg/g，说明该复合材料(G-nZVI)在含铀放射性废水的处理与环境修复中具有潜在的应用价值。
关键字: 石墨；纳米零价铁；负载；铀；去除
（State Key Laboratory Breeding Base of Nuclear Resources and Environment, East Chain University of Technology, Jiangxi 330013, China）
Abstract:The nano-zero-valent iron was prepared by liquid phase reduction method and loaded on the surface of graphite powder to form graphite-loaded nano-zero-valent iron composite (G-nZVI). The materials were used to remove U(Ⅵ) from the solution. The effects of initial solution pH, reaction temperature and time, initial concentration of U(Ⅵ) and solid-liquid ratio on the removal of U(Ⅵ) from composite materials (G-nZVI) were investigated. The composites before and after the reaction were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) to analyze the mechanism of U(Ⅵ) removal. The research results show that nano-zero-valent iron particles are dispersed on the surface of graphite powder and there is no agglomeration phenomenon. Mainly components are UO2 and U(Ⅳ) hydroxide precipitate in the solution after the reaction. Graphite-loaded nano-zero-valent iron has a good adsorption effect on U(Ⅵ). The removal rate and adsorption capacity of U(Ⅵ) reach 99.67% and 43.2 mg/g, respectively, when the conditions of pH value is 4.0, temperature is 30 ℃, reaction time is 60 min, solid-liquid ratio is 0.25 g/L, initial U(Ⅵ) concentration is 10 mg/L. The result shows that the composite material (G-nZVI) has potential application value in the treatment and environmental restoration of uranium-containing radioactive wastewater.
Key words: graphite powder; nano-zero-valent iron; uranium; loading; removal
