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Weida Wang Yali Feng Xinhua Tang Haoran Li Zhuwei Du Aifei Yi Xu Zhang 《环境科学学报(英文版)》2015,27(5):68-73
Uranium-reducing bacteria were immobilized with sodium alginate, anthraquinone-2, 6-disulfonate (AQDS), and carbon nanotubes (CNTs). The effects of different AQDS-CNTs contents, U(IV) concentrations, and metal ions on U(IV) reduction by immobilized beads were examined. Over 97.5% U(VI) (20 mg/L) was removed in 8 hr when the beads were added to 0.7% AQDS-CNTs, which was higher than that without AQDS-CNTs. This result may be attributed to the enhanced electron transfer by AQDS and CNTs. The reduction of U(VI) occurred at initial U(VI) concentrations of 10 to 100 mg/L and increased with increasing AQDS-CNT content from 0.1% to 1%. The presence of Fe(III), Cu(II) and Mn(II) slightly increased U(VI) reduction, whereas Cr(VI), Ni(II), Pb(II), and Zn(II) significantly inhibited U(VI) reduction. After eight successive incubation-washing cycles or 8 hr of retention time (HRT) for 48 hr of continuous operation, the removal efficiency of uranium was above 90% and 92%, respectively. The results indicate that the AQDS-CNT/AL/cell beads are suitable for the treatment of uranium-containing wastewaters. 相似文献
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Hang Zhang Shuo Chen Haiguang Zhang Xinfei Fan Cong Gao Hongtao Yu Xie Quan 《Frontiers of Environmental Science & Engineering》2019,13(2):18
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碳纳米管对亚甲基蓝的吸附性能研究 总被引:2,自引:0,他引:2
碳纳米管的一维管状中空结构,对有机物具有吸附能力,有望用于废水处理.本文通过理论分析和试验验证,探讨了采用碳纳米管时亚甲基蓝溶液浓度、溶液pH值、吸附时间和吸附温度等对吸附过程的影响,分析了碳纳米管对亚甲基蓝的吸附机理.结果表明,碳纳米管对亚甲基蓝的吸附在3 h达到平衡,吸附速率常数为384.49 h-1;吸附过程遵循Langmiur方程;碱性条件有利于吸附的进行;随着温度的升高,碳纳米管对亚甲基蓝的吸附量增加.吸附机理为,碳纳米管对亚甲基蓝的吸附是一个吸热过程,第一层吸附包含物理吸附和化学吸附,而多层吸附则是物理吸附. 相似文献
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Uranium-reducing bacteria were immobilized with sodium alginate, anthraquinone-2,6-disulfonate(AQDS), and carbon nanotubes(CNTs). The effects of different AQDS-CNTs contents, U(Ⅳ) concentrations, and metal ions on U(Ⅳ) reduction by immobilized beads were examined. Over 97.5% U(Ⅵ)(20 mg/L) was removed in 8 hr when the beads were added to 0.7% AQDS-CNTs, which was higher than that without AQDS-CNTs. This result may be attributed to the enhanced electron transfer by AQDS and CNTs. The reduction of U(Ⅵ) occurred at initial U(Ⅵ) concentrations of 10 to 100 mg/L and increased with increasing AQDS-CNT content from 0.1% to 1%. The presence of Fe(Ⅲ), Cu(Ⅱ) and Mn(Ⅱ)slightly increased U(Ⅵ) reduction, whereas Cr(Ⅵ), Ni(Ⅱ), Pb(Ⅱ), and Zn(Ⅱ) significantly inhibited U(Ⅵ) reduction. After eight successive incubation-washing cycles or 8 hr of retention time(HRT) for 48 hr of continuous operation, the removal efficiency of uranium was above 90% and 92%, respectively. The results indicate that the AQDS-CNT/AL/cell beads are suitable for the treatment of uranium-containing wastewaters. 相似文献
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碳纳米管基复合吸附剂的制备及其吸附性能 总被引:2,自引:0,他引:2
为了解决碳纳米管(CNTs)在吸附水中污染物时易聚集、难分离的问题,本文采用静电自组装技术将碳纳米管固定化在具有微米级粒径的碳酸钙颗粒表面,设计制备了壳-核结构的CNTs基复合吸附剂.实验考查了不同碳纳米管分散体系对复合吸附剂制备的影响,并采用Zeta电位、拉曼光谱、扫描电镜等手段对复合吸附剂的制备过程和结构进行表征,探讨了制备的碳纳米管基复合吸附剂对菲的吸附性能.结果发现,复合吸附剂对菲的吸附能力随CNTs载量的增加而增大,CNTs标化的吸附系数则随CNTs载量的增加而下降,碳纳米管是复合吸附剂的主要吸附位点. 相似文献
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研究了不同分子结构的天然有机物质(NOM)模型化合物单宁酸(TA)、没食子酸(GA)和十二烷基苯磺酸钠(SDBS)对碳纳米管(CNTs)分散性的影响.通过计算得出,TA的临界胶束浓度(CMC)为1.12mmol/L,SDBS的CMC为0.24mmol/L,GA在所测试的浓度范围内没有形成胶束.比较NOM在CNTs表面的吸附过程和CNTs的分散过程,表明空间位阻和胶束包裹是2个促进CNTs分散的主要机理.借助透射电子显微镜(TEM)和测量悬浮的CNTs的平均流体动力学直径(DLS)结果表明,TA在较少的固相吸附量(Se ≈ 0.01mmol/g)就能使CNTs分散,归因于其吸附后刚性芳香三维结构的TA能形成的较大空间位阻;同样具有芳香平面结构的GA分子在CNTs表面的吸附需要达到一定的厚度(Se > 0.2mmol/g),才能有效地分散CNTs;具有烷基脂肪链的SDBS,需要在形成半胶束或胶束后(Se > 0.13mmol/g) CNTs才能有效地被分散.芳香族刚性结构和脂肪族柔性结构的模型化合物对CNTs的分散效果和机理存在较大的差别. 相似文献
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为探究碳纳米管(Carbon Nanotubes,CNTs)预沉积改性膜的污染机理,本研究使用正压过滤法将CNTs预沉积在3种孔径的有机膜(20 kDa聚醚砜膜、0.01 μm和0.1 μm聚偏二氟乙烯膜)表面,研究了CNTs预沉积改性膜过滤3种典型污染物(牛血清蛋白、腐殖酸、海藻酸钠)过程中的膜污染情况.根据比通量、Hermia模型和传统滤饼过滤模型,对恒压死端过滤3种典型污染物过程中的污染机理进行了系统评价.结果表明,20 kDa PES膜和0.01 μm PVDF膜表面预沉积CNTs改性后,过滤3种典型膜污染物质时的膜污染情况都得到了一定程度的缓解.20 kDa PES膜表面预沉积CNTs后过滤HA初期为完全孔堵塞与滤饼过滤相结合的复合污染机理,最终转变为滤饼过滤;过滤SA的污染机理为完全孔堵塞与滤饼过滤相结合的复合污染机理.0.01 μm PVDF膜表面沉积CNTs改性后过滤HA初期的污染机理为膜孔堵塞与滤饼过滤相结合的复合污染机理,然后经过向滤饼过滤转变的过渡阶段,最终形成滤饼过滤,且随着CNTs沉积量的增加,过渡阶段持续时间延长.0.1 μm PVDF膜表面预沉积CNTs后过滤3种污染物,均未能缓解膜污染,膜污染机理不受CNTs沉积改性的影响,其过滤BSA和HA的污染机理为膜孔堵塞,过滤SA过程的污染机理符合滤饼过滤. 相似文献
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Shuo Wei Lei Du Shuo Chen Hongtao Yu Xie Quan 《Frontiers of Environmental Science & Engineering》2021,15(1):11