摘要
以造纸厂厌氧颗粒污泥为原料制备的粉末厌氧颗粒污泥(PAGS)作为生物吸附剂,研究pH值、吸附剂PAGS的用量、U(Ⅵ)初始浓度和吸附时间对PAGS吸附U(Ⅵ)的影响。采用模型模拟、扫描电镜分析、能谱分析、红外光谱分析和离子交换试验等手段探讨PAGS吸附U(Ⅵ)的机理。结果表明,在U(Ⅵ)初始浓度为10 mg/L、温度为30℃时,PAGS吸附U(Ⅵ)的最佳条件是pH值为6,PAGS用量为2.0 g/L,吸附平衡时间为60 min。用准二级动力学模型(R2≈1)和Freundlich等温模型(R2>0.99)均可较好地拟合其吸附过程。扫描电镜、能谱分析和离子交换试验结果表明,离子交换是PAGS吸附U(Ⅵ)的主要方式,参与交换的主要离子为Ca2+;红外光谱分析表明配位络合也是其吸附机理之一,参与络合作用的主要基团有—OH、C=O、Si—OH和—NH2。以0.1 mol/L的HCl溶液作为解吸液,初次解吸率达99%,表明PAGS可再生且无毒、生态友好,具有较好的重复利用性,在含铀废水处理中具有广阔的应用前景。
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＆gt;0.99）. SEM images, EDS analysis results and ion exchange experiments verify that ion exchange is the main adsorption mechanism with Ca^2＋ 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.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2014年第9期2418-2425,共8页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(11175081
11475080)
高等学校博士点基金资助项目(20134324110003)
湖南省自然科学基金资助项目(13JJ3078)
湖南省高校创新平台项目(13K085)
关键词
粉末厌氧颗粒污泥
铀(Ⅵ)
吸附
解吸
离子交换
powdered anaerobic granular sludge
uranium （Ⅵ）
absorption
desorption
ion exchange
