吸附法海水提铀材料研究进展

吸附法是海水提铀的最适宜方法之一,选择性好且吸附效率高的吸附材料是从海水中提取铀的最佳材料。本文回顾了到目前为止吸附法海水提铀的无机、有机、无机/有机杂化材料的制备方法、结构、吸附性能和铀吸附机理,介绍了不同海水提铀装置的结构和吸附性能。由于有机/无机杂化材料具有高机械强度、高铀吸附量、低共存离子干扰等优点,是一种理想的海水提铀材料;而且膜式吸附装置由于操作流程简单、可连续化等优点,是一种较佳的吸附方式。开展高铀吸附量、高选择性的吸附剂和处理量大的吸附方式是今后吸附法海水提铀的重要研究方向。     

生物高分子/氧化石墨烯复合材料对铀的吸附研究进展

随着核能事业的快速发展,大量含铀废水被排放到环境中,对环境造成污染。减少废水中铀的危害,同时有效回收利用有限的铀资源是当下热点问题。本文介绍了目前国内外含铀废水的处理方法及存在的问题,重点论述了近年来生物高分子/石墨烯基复合材料吸附水溶液中铀的研究现状。     

基于海水提铀的多孔芳香框架材料研究进展

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。     

吸附法提取低浓度铀的研究进展

综述了国内外吸附法提取低浓度铀的研究进展,分析了不同铀吸附材料的特点与性能,介绍了其综合利用现状与应用前景,并对吸附提铀研究的发展方向提出了建议。     

改性竹基生物炭对铀的吸附特性及其机理分析

为了去除水体中的铀污染,以毛竹为原料,采用化学活化法制备改性竹基生物炭吸附材料。考察了吸附时间、吸附剂投加量、溶液初始pH和初始铀浓度对吸附效果的影响。通过扫描电镜、能谱分析、傅立叶变换红外光谱等分析手段,研究了改性竹基生物炭材料对铀吸附前后表面性质的变化。研究结果表明,改性竹基生物炭材料适用于pH为4.5的含铀水溶液的处理,并且该材料对铀的去除率远远高于竹基生物炭材料。     

铀的吸附材料研究进展

本文对近几年来铀的吸附工作做了一定程度的概述,重点在于这些年所做的研究工作以及研究成果。概述了一些生物质材料、高分子材料、纳米材料、天然矿石材料以及微生物材料等对铀的吸附研究,并对其中的某些材料的吸附过程进行了深刻的理解,同时指出某些材料在铀吸附上的缺点。本文对今后的铀吸附工作具有一定的指导意义,进一步指出铀的吸附材料研究工作的具体方向。     

含铀废水生物吸附处理的研究进展

综述了国内外利用生物吸附剂对含铀废水的处理现状,介绍了生物吸附技术的定义,生物吸附剂的分类与优势以及影响吸附过程的各种因素,分析了不同种类生物质材料对含铀废水的处理的特点与性能,并对生物技术未来的发展方向提出了建议。     

含铀废水生物吸附处理的研究进展

综述了国内外利用生物吸附剂对含铀废水的处理现状,介绍了生物吸附技术的定义,生物吸附剂的分类与优势以及影响吸附过程的各种因素,分析了不同种类生物质材料对含铀废水的处理的特点与性能,并对生物技术未来的发展方向提出了建议。     

纤维基吸附材料在海水提铀中的应用

介绍了纤维基吸附剂及其制造方法和应用实施情况。主要涉及高比表面纤维、聚合物吸附剂辐射接枝技术、海上作业以及回收铀的洗脱与纯化处理,并对纤维基吸附剂海水提铀的成本作了分析和说明。指出:近年来,国际上采用纤维基吸附剂从海水中提铀技术已取得了长足进展,开展这一方面的研究具有实际的技术经济效益和环境意义;建议我国尽快启动此项研究活动。     

吸附分离水体中铀的吸附材料研究新进展

铀是最危险的放射性金属之一,广泛存在于核燃料的制备、乏燃料后处理和矿石开采等生产活动所产生的含铀废水中,严重威胁水生生态系统与人类健康。吸附法处理水中的U(Ⅵ)具有便捷高效、经济和选择性好的优势。综述了近3年对水中铀吸附材料的研究新进展,介绍了无机、有机、有机无机复合和生物衍生类吸附材料的制备,结构特点,吸附性能,并对铀吸附材料的研究方向进行了展望。     

Recovery of Uranium from Seawater: A Review of Current Status and Future Research Needs

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.     

Extraction of Uranium from Seawater Using Magnetic Adsorbents

Abstract

A new process for the extraction of uranium from seawater was developed. In the process, uranium adsorption is effected using powdered magnetic adsorbents; the adsorbents are then separated from seawater using magnetic separation technology. This process is superior to a column method using a granulated hydrous titanium oxide adsorber bed in the following ways: (1) a higher rate of adsorption is realized because smaller particles are used in the uranium adsorption; and (2) blocking, which is inevitable in an adsorber bed, is eliminated.

The composite hydrous titanium-iron oxide as a magnetic adsorbent having high uranium adsorption capacity and magnetization can be prepared by adding urea to a mixed solution of titanium sulfate and ferrous sulfate. Adsorption and desorption of uranium and the removal of the adsorbent using a small-scale uranium extraction plant (about 15 m³/d) is reported, and the feasibility of uranium extraction from seawater by this process is demonstrated.     

固体废弃物吸附含铀（Ⅵ）废水的应用及性能

社会经济的发展和人类活动的进行导致固体废弃物数量和种类不断增加，固体废弃物资源化成为世界范围内的热点话题。在双碳背景下，重视循环经济的发展，废弃物资源化有较大的提升空间。核工业核技术的迅速发展产生了含铀放射性废水，利用固体废弃物制成吸附材料对含铀（Ⅵ）废水处理可达到“以废治废”的目的，缓解环境污染问题，利于可持续发展。归纳了一些主要的可应用在除铀方面的固体废弃物材料，如农林业固体废弃物、工业固体废弃物以及城市固体废弃物；介绍了固体废弃物吸附材料的制备和改性方法以及除铀机理；并对今后铀吸附材料的研究方向进行了展望，指出今后铀吸附材料应向高效吸附、绿色环保、高附加值方向发展。     

New and simple synthetic strategy for two-dimensional ultra-microporous aromatic framework for selective uranium capture in liquid

Uranium is a key element to improve nuclear energy demands, and thereby the extraction of uranium from seawater is a strategic way to address uranium sustainability. Herein, a novel two-dimensional porous aromatic framework (AO-PAF), which possesses an ultra-microporous architecture with an ordered structure, excellent stability and selectivity of uranium extraction from a liquid phase. AO-PAF shows excellent uranium adsorption capacities of 637 (mg/g) and 3.22 (mg/g) in simulated and natural seawater attributable to the selective uranium coordinating groups on highly accessible pores on the walls of open channels. In addition, benefiting from the super-hydrophilicity due to the presence of amidoxime groups attributes high selectivity and ultrafast kinetics with an uptake rate of 0.43 ± 0.03 (mg/g·day) and allowing half-saturation within 1.35 ± 0.09 days. This strategy demonstrates the potential of PAF not only recovery of uranium and can be extended for other applications by sensible planning of target ligands.     

Recovery of Uranium from Seawater

Abstract

Seawater contains various elements in solution. Deuterium, lithium, and uranium are the important ingredients for energy application at present and in the future. This paper deals with the recovery of uranium from seawater, with emphasis on the development of an adsorbent with high selectivity and rate of adsorption for uranium.

Polyacrylamidoxime chelating resins were synthesized from various co-polymers of acrylonitrile and cross-linking agents. The resulting resins with the chelating amidoxime group showed selective adsorption for uranium in seawater. The amount of uranium adsorbed from seawater at room temperature reached 3.2 mg/g resin after 180 days.

Polyacrylamidoxime fiber, which was prepared from polyacrylo-nitrile fiber and hydroxylamine, showed a high rate of adsorption for uranium. The polyacrylamidoxime fiber conditioned with 1 M HCl and 1 M NaOH adsorbed 4 mg U/g fiber from seawater in ten days.     

Design and Cost Studies on the Extraction of Uranium from Seawater

Abstract

For a country like Japan, which has very limited energy resources, nuclear power generation is an attractive energy option. However, since known domestic resources of uranium are limited, it is desirable to develop less-conventional uranium sources. To investigate the technical and economic feasibility of extracting uranium from seawater, a research program has been carried out since 1975 by the Metal Mining Agency of Japan, under sponsor-ship of the Ministry of International Trade and Industry. The program includes studies in the following research areas: chemical process selection, adsorbent development, continuous adsorption and elution performance, eluate recovery by steam stripping or electrodialysis, and secondary concentration of uranium in the eluate. Several site selections around the Japanese coast have been examined along with a comparison of various seawater contacting structures. Conceptual designs and tentative cost estimations have been conducted on two types of commercial plants: pumping and fixed bed, and direct sea current utilization. This paper summarizes the conceptual design and cost estimation results.     

含铀废液吸附处理的研究进展

随着核工业的发展,含铀废液的污染日益严重。近年来,吸附法广泛应用于含铀废液的处理。本文综述了粘土矿物,天然有机物,合成高分子和炭材料的吸附研究进展。     

生物质基碳气凝胶的研究进展

碳气凝胶是一种新型的纳米多孔碳材料,具有孔隙率高、比表面积大、导电性能优良、耐高温等优点,在催化剂载体、电容器及吸附材料等领域具有广阔的应用前景。与传统的碳气凝胶相比,生物质基碳气凝胶具有前驱体环保可再生的优势,可为生物质高值化、功能化利用提供新思路。本文在简单介绍生物质基碳气凝胶制备过程（包括溶胶-凝胶化、干燥、炭化）的基础上,重点介绍了3类来自不同生物质前驱体（植物纤维素、细菌纤维素和具有三维多孔结构的植物本身）碳气凝胶的制备方法,并对碳气凝胶及其复合材料在催化剂载体、吸附材料、超级电容器、锂离子电池方面的应用进行了综述,最后对生物质基碳气凝胶的研究方向和发展前景进行总结和展望。     

电化学提锂技术中电极材料和电极体系的研究进展

锂及其化合物具有广泛的应用前景，锂资源需求越来越大，因此，开发能实现高储量、低品位的（浓）海水/卤水锂资源高效提取的方法具有重要意义。近年来，电化学提锂技术因其高选择性、低能耗和环境友好等特点而成为研究热点。本文针对电化学提锂技术中锂吸附电极材料的选择/制备和电极体系构建两方面的研究进展进行了归纳分析。在锂吸附电极材料的选择/制备上，基于高锂离子选择性的LiFePO₄、LiMn₂O₄和LiNi_1/3Co_1/3Mn_1/3O₂电极被逐渐开发应用。在电极体系构建上，与具有阴离子可逆交换性能的AgCl、ZnCl₂和聚吡咯对电极所构成的电极体系可避免副反应发生，能耗较低；不含其他对电极材料的“摇椅式”结构电极体系可降低电极成本，提高提锂效率。此外，指出了目前电化学提锂技术尚存在的不足，未来可从电极材料制备、提锂过程优化、装备设计三方面进行研究，以推进电化学提锂技术的发展与应用。