(南華大學(xué) 污染控制與資源化技術(shù)湖南省高校重點實驗室，衡陽 421001)
摘 要: 以造紙廠厭氧顆粒污泥為原料制備的粉末厭氧顆粒污泥(PAGS)作為生物吸附劑，研究pH 值、吸附劑PAGS的用量、U(Ⅵ)初始濃度和吸附時間對PAGS 吸附U(Ⅵ)的影響。采用模型模擬、掃描電鏡分析、能譜分析、紅外光譜分析和離子交換試驗等手段探討PAGS 吸附U(Ⅵ)的機理。結(jié)果表明，在U(Ⅵ)初始濃度為10 mg/L、溫度為30 ℃時，PAGS 吸附U(Ⅵ)的最佳條件是pH 值為6，PAGS 用量為2.0 g/L，吸附平衡時間為60 min。用準二級動力學(xué)模型(R2≈1)和Freundlich 等溫模型(R2＞0.99)均可較好地擬合其吸附過程。掃描電鏡、能譜分析和離子交換試驗結(jié)果表明，離子交換是PAGS 吸附U(Ⅵ)的主要方式，參與交換的主要離子為Ca2+；紅外光譜分析表明配位絡(luò)合也是其吸附機理之一，參與絡(luò)合作用的主要基團有—OH、C=O、Si—OH 和—NH2。以0.1 mol/L 的HCl 溶液作為解吸液，初次解吸率達99%，表明PAGS 可再生且無毒、生態(tài)友好，具有較好的重復(fù)利用性，在含鈾廢水處理中具有廣闊的應(yīng)用前景。
關(guān)鍵字: 粉末厭氧顆粒污泥；鈾(Ⅵ)；吸附；解吸；離子交換
（Hunan Provincial Key Laboratory of Pollution Control and Resources Reuse Technology,
University of South China,Hengyang 421001,China）
Abstract:The anaerobic granular sludge from a paper mill was used to prepare powdered anaerobic granular sludge (PAGS) as a novel biological adsorbent. Experimental parameters such as pH value,adsorbent PAGS dosage,initial U(Ⅵ) concentration and adsorption time were examined to investigate their effects on the adsorption of U(Ⅵ) by PAGS. The adsorption mechanism was studied by model simulation,scanning electron microscopy,energy-dispersive spectrometry,infrared spectroscopy and ion exchange experiments. The results show that the maximum adsorption occurs at pH value of 6,adsorbent PAGS dosage of 2.0 g/L and adsorption time of 60 min for an initial U(Ⅵ) concentration of 10 mg/L and 30 ℃. The equilibrium data fit well with the pseudo-second-order model (R2≈1) and Freundlich model (R2>0.99). SEM images,EDS analysis results and ion exchange experiments verify that ion exchange is the main adsorption mechanism with Ca2+ as the main exchange ion. FTIR spectra show that complexation is also one of the adsorption mechanisms with —OH,C=O,Si—OH and —NH2 as the major functional groups involved．The used PAGS can be desorbed by 0.1 mol/L HCl (the first desorption rate is up to 99%) and can be reusable. PAGS is nontoxic and eco-friendly,which has a good prospect in the treatment of uranium-containing wastewater.
Key words: powdered anaerobic granular sludge; uranium (Ⅵ); absorption; desorption; ion exchange
