共查询到19条相似文献,搜索用时 453 毫秒
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多孔芳香框架材料是一类新兴的有机多孔纳米材料,具有稳定性高、比表面积大、易于修饰改性等特点,可以满足多种吸附材料设计的需求。近几年众多学者将修饰改性后的多孔芳香框架材料应用于海水提铀,发现其具有较大的铀吸附量、优异的铀选择性、良好的可循环性等特点。本文综述了近年来基于海水提铀的多孔芳香框架材料的研究进展,首先简要介绍了其合成反应与合成技术,然后分类讨论了与铀的相互作用机理,并评估了多种改性多孔芳香框架材料对铀的吸附性能,分析了其对铀的高选择性和高吸附效率的原因。最后,本文针对目前多孔芳香框架材料在海水提铀中的局限性(多孔芳香框架材料的合成、吸附性能的提高、成本的降低及机理的深层次研究等)为未来设计低成本高性能的多孔芳香框架材料吸附剂提供了几点建议。 相似文献
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铀资源是国家核工业发展的重要战略资源,安全可持续铀资源供应是核电健康发展的关键。除铀矿资源外,绿色海水提铀技术是最有应用潜力的铀资源供应途径。吸附法是海水提铀和含铀废水处理的常见方法,面对复杂的海洋环境,设计和制备吸附量大、选择性高的吸附材料成为解决问题的关键,以高附加值的生物质基材料为铀吸附剂是一种新型的可持续发展策略。本文详细综述了生物质基铀吸附材料的分类、制备方法及其吸附性能,概括了生物质基吸附材料的研究现状和热点,基于研究现状,展望了未来高效生物质基吸附材料在海水提铀方面的发展方向和研究趋势。 相似文献
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锂及其化合物既是一种绿色能源材料也是重要的战略物资。其在相关产业领域具有重要应用且需求量一直保持较高速度增长。海水、盐湖卤水中蕴藏着储量巨大的锂矿资源,为了满足强劲的市场需求,从海水、盐湖卤水中分离提取锂资源具有重要的经济价值与战略意义。由于卤水中锂离子浓度低、成分复杂、盐湖卤水还具有高镁锂比特点,选择性分离提取锂资源显得至关重要。本文以锰系离子筛、钛系离子筛、有机冠醚及其衍生物等选择性吸附单元为出发点,分别分析了各自的结构特点及吸附提锂机制,对基于锰系、钛系和有机冠醚及其衍生物的复合提锂吸附材料的制备方法等方面进行了综述。对基于以上选择性吸附单元的复合吸附材料制备研究现状进行了总结,指出了仍然存在的问题,对今后选择性吸附材料的制备及应用进行了展望。 相似文献
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《分离科学与技术》2012,47(3):367-387
The recovery of uranium (U) from seawater has been investigated for over six decades in efforts to secure uranium sources for future energy production. The majority of the research activities have focused on inorganic materials, chelating polymers, and nanomaterials. Previous studies of uranium adsorption from aqueous solutions, mainly seawater, are reviewed here with a focus on various adsorbent materials, adsorption parameters, adsorption characterization, and marine studies. Continuous progress has been made over several decades, with adsorbent loadings approaching 3.2 mg U/g adsorbent in equilibrium with seawater. Further research is needed to improve first, the viability including improved capacity, selectivity, and kinetics, and second, the sorbent regeneration for multicycle use. An overview of the status of the uranium adsorption technology is provided and future research needs to make this technology commercially competitive are discussed. 相似文献
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蒙脱石( Montmorillonite)因其具有较大的比表面积、丰富的孔结构及低廉的成本,在众多领域广泛应用。尤其在工业废水处理领域,与传统的吸附剂相比,蒙脱石因其特殊的结构,可以通过无机改性来改善其孔结构、提高其比表面积,从而提高其吸附容量;通过有机改性来改善其表面疏水性,增加对有机分子间的亲和力,为拓展蒙脱石在工业废水处理领域中的应用提供了新思路。本文阐述了蒙脱石的结构、性质以及改性方法,在此基础上,着重归纳了无机-有机柱撑蒙脱石在工业废水处理中的应用研究状况,并对研究前景进行了展望。 相似文献
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以聚丙烯腈纤维(PANF)为基体与盐酸羟胺反应制得偕胺肟基改性纤维(AO-PANF),并通过扫描电镜、红外光谱和批次吸附,探究了AO-PANF对高氟高氯含铀废水中铀的螯合行为。结果表明,偕胺肟化反应将PANF中的氰基成功转化为偕胺肟基团,转化率随盐酸羟胺浓度增加而增大,氰基转化率为22.34%时,AO-PANF对铀的吸附量最大。随废水pH增加,AO-PANF对铀的吸附量先增大后减小,pH为5时,其值最大。F-和Cl-浓度变化对AO-PANF的吸附量影响较小。当处理100 ml铀初始浓度为100 mg·L-1,pH为5的废水,温度为45℃,吸附剂投加量为0.40 g时,转化率为22.34%的AO-PANF对铀的吸附量为19.53 mg·g-1,3 h左右吸附达到平衡。AO-PANF通过偕胺肟基团中-NH2与废水中UO2F42-螯合实现对铀的吸附。该吸附过程符合Freundlich等温吸附模型和准二级动力学方程。研究表明AO-PANF可以有效地螯合高氟高氯含铀废水中的铀,具有良好的应用前景。 相似文献
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Guillermo San Miguel Steven D Lambert Nigel JD Graham 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(10):1685-1696
A wide range of materials known for their adsorption properties have the potential for being used for the removal of trace substances from drinking and wastewaters. These include physically and chemically activated carbons, surface modified carbons, non‐porous resins with ion exchange capacities, inorganic microporous solids like zeolites and clays, and mixed organic–inorganic materials like bone chars. The adsorption capacity exhibited by each material relates primarily to its textural and chemical properties. Other factors, however, such as apparent density, regeneration potential and cost, need to be taken into consideration when selecting one adsorbent over another. A comparative investigation of 18 solids and their capacity to remove organics and metals from natural waters and solutions reconstituted to simulate the conditions in natural waters is presented. The experiments were carried out using batch and small‐scale column adsorption tests. In general, zeolites and ion exchange resins exhibited limited capacities to remove organic matter from solution but were highly effective with metallic species like manganese and aluminium. Activated carbons adsorbed organic matter very efficiently, with results showing a correlation between adsorption capacity and surface area (up to 1791 m2 g?1). Metal removal was highly variable and was enhanced in activated carbons subjected to acid washing. Owing to its mixed organic/inorganic nature, and despite its poorly developed micropore structure, bone char exhibited a strong adsorption capacity for both organic and metal species. The high apparent density of this material (0.763 g cm?3) meant that its performance was greatly improved when tests were conducted on the basis of volume, matching and surpassing the performance of the best carbons. The possibility of using mixtures of complementary adsorbents for the removal of organic and inorganic species from solution was also successfully evaluated in this work. Copyright © 2006 Society of Chemical Industry 相似文献
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