(東華理工大學 核資源與環(huán)境國家重點實驗室，南昌 330013)
摘 要: 以液相還原法制備納米零價鐵，將其負載于石墨表面制備負載型納米零價鐵復合材料(G-nZVI)，并用來去除溶液中的U(Ⅵ)，考察初始溶液的pH、反應溫度、反應時間、U(Ⅵ)的初始濃度以及固液比等因素對復合材料(G-nZVI)去除U(Ⅵ)影響。用掃描電鏡(SEM)和X射線衍射(XRD)技術對反應前后的材料進行表征，分析其去除U(Ⅵ)的機理。結(jié)果表明：納米零價鐵顆粒分散在石墨粉的表面，沒有產(chǎn)生團聚。反應后溶液中主要生成UO2和U(Ⅳ)氫氧化物沉淀。石墨負載型納米零價鐵對U(Ⅵ)有很好的去除效果，在pH為4.0，溫度為30 ℃，反應時間為60 min，固液比為0.25 g/L，初始U(Ⅵ)濃度為10 mg/L條件下，U(Ⅵ)的去除率和吸附容量分別達到99.67%和43.2 mg/g，說明該復合材料(G-nZVI)在含鈾放射性廢水的處理與環(huán)境修復中具有潛在的應用價值。
關鍵字: 石墨；納米零價鐵；負載；鈾；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
