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。     

吸附铀元素材料的研究进展

综述了吸附材料在吸附铀应用的研究进展。吸附材料包括无机材料、有机材料以及生物材料。     

生物质基铀吸附材料的研究进展

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。     

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。     

磁性石墨烯对铀的吸附性能研究

利用氧化石墨烯和Fe Cl3·6H2O制备了磁性氧化铁材料(GNs-Fe3O4),并利用扫描电镜进行了形貌表征。将材料用于铀(VI)离子的吸附,研究了溶液p H值,吸附时间,铀(VI)溶液初始浓度和温度对吸附效果的影响。研究表明,GNs-Fe3O4对铀(VI)吸附的最佳p H值为5.5,3h达到吸附平衡,材料对铀(VI)的最大饱和吸附量为72mg/g。吸附符合准二级动力学模型,表明吸附行为受化学作用控制,吸附过程可用Langmuir等温式描述。     

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。     

粒状偕胺肟基蒙脱土纳米吸附材料的制备及铀吸附性能

采用PVC为粘合剂制备粒状偕胺肟基蒙脱土材料,选取粒径范围为0.8-1.7 mm颗粒进行铀吸附试验,考察了实验条件对铀吸附性能的影响,并对其吸附动力学进行了初步探讨。结果表明,当PVC、偕胺肟基蒙脱土、DMF、KCl的质量比为1.0:1.0:6.0:0.4时,粒状材料的成型效果较好。该材料对铀的吸附随时间的增加而增加,并在60 h后达到饱和。当铀初始浓度较大、吸附温度较高、振荡吸附方式时,其铀吸附速率较快;当铀溶液的pH=3时,该材料对铀的平衡吸附量最高。该材料铀的饱和吸附量达10.55 mg/g。动力学研究表明,该粒状吸附剂对铀的吸附控制步骤为液膜扩散控制,吸附速率常数为0.000 5 min-1;20℃下的吸附过程符合Freundlich吸附等温方程,qe=0.2137ce0.772 6。     

焦粉基碳吸附材料对含铜废水处理研究

用硝酸预氧化焦粉、氯化锌化学活化法制备了焦粉基碳吸附材料。静态法考察了焦粉基碳吸附材料对水中铜离子的吸附工艺参数、吸附模型、温度对吸附过程的影响。研究表明：焦粉基碳吸附材料对水中铜离子的吸附工艺参数为：铜离子溶液浓度80mg／L、吸附平衡时间50min、吸附温度为40℃、pH为5．0～6．0;该吸附过程符合Langmuir型吸附模型;温度升高有利于焦粉基碳吸附材料对铜离子的吸附,表明该吸附为吸热过程。     

碳材料吸附去除水中抗生素的研究进展

综述了碳材料用于吸附去除水中抗生素的研究进展。简要介绍了碳材料对水中抗生素的吸附机理,主要是物理吸附、化学吸附以及静电相互作用。重点介绍了传统型碳材料、新型碳材料、纳米碳材料以及复合材料在抗生素吸附去除中的应用现状,并且比较了以上4种碳材料对水中抗生素的吸附特点,总结目前碳材料对抗生素的吸附缺陷。最后展望未来碳材料吸附去除水中抗生素的研究方向,提出未来需要关注复合材料和复合工艺对抗生素的吸附去除,充分利用组合技术的优势。     

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。     

Facile and Eco-Friendly Fabrication of Multifunctional Melamine Sponge for Labeled Cr(VI) Removal and Highly Efficient Oil/Water Separation

Fabrication of multifunctional adsorbent of single-phase material is quite challenging and meaningful for water treatment. In this work, a polyaminosiloxane functionalized melamine sponge is used to remove both heavy metal ions and oil from water. Benefiting from its porous structure, superhydrophobic surface, and abundant amino groups on the surface, the sponge shows excellent performance in Cr(VI) removal and oil/water separation. Notably, the sponge exhibits fluorescent detection function for Cr(VI) owing to the packing of Schiff-base bonds, facilitating the adsorption process to be monitored in real time. The maximum adsorption capacity of Cr(VI) is 252.82 mg g⁻¹ with good selectivity. In addition to the excellent Cr(VI) removal performance, its superhydrophobic nature allows it to adsorb 92.42 times the weight of oil and realize 99.97% oil/water separation efficiency. This trifunctional cost-effective adsorption material shows great potential for large-scale water purification application.     

Kinetic,isotherm, and thermodynamic studies of Cr(VI) removal from aqueous solution using mesoporous silica materials prepared by fly ash

A series of mesoporous silica materials (FMD, FMT, and FMC were synthesized with DTAB, TTAB, and CTAB as template, respectively) have been prepared using fly ash as a silica resource. The as-synthesized materials were characterized by BET, XRF, FTIR, and XPS. The results confirmed the mesoporous structure and nitrogen content to act as potential adsorbents. The adsorption properties of these materials were also investigated by batch adsorption experiments. The FMC exhibited the highest effective removal of Cr(VI) (99%). The Cr(VI) adsorption process over FMC follows the pseudo-second-order kinetic and Langmuir model. Thermodynamic studies revealed that the Cr(VI) adsorption by FMC was spontaneous and endothermic. The study of the adsorption mechanism showed that the removal of Cr (VI) by FMC is through electrostatic attraction and chemical reduction. The coexisting ions experiment showed that FMC had high selectivity for Cr(VI). After three regeneration cycles, the Cr(VI) removal rate of FMC adsorbent still remained about 80%. Thus, this inexpensive adsorbent (FMC) is suitable for removing Cr(VI) from discharged industrial water.     

纳米零价铁强化高岭石去除水中Cr(VI)及机制研究

纳米零价铁(nZVI)作为一种治理重金属、核素污染物的环保材料而被广泛关注,而黏土矿物作为常见的重金属吸附材料虽成本低廉、来源广泛,但去除性能又普遍有限。通过液相还原法制备nZVI/高岭石复合材料来强化高岭石去除水中Cr(VI)的性能,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)技术对其结构进行表征,考察了Cr(VI)初始浓度、nZVI/高岭石投加量、温度等条件对Cr(VI)去除率的影响,并探讨了其对水中Cr(VI)的去除能力及机制。结果表明,nZVI/高岭石中的nZVI结晶度低,粒径在50~100 nm,nZVI/高岭石在60 min时对Cr(VI)的去除率达91.7%,分别比nZVI和高岭石提高了2.7倍和18.5倍。nZVI/高岭石对Cr(VI)的去除动力学符合准二级动力学模型,表观反应活化能为27.97 kJ/mol,去除是吸附、还原和共沉淀共同作用的结果。通过nZVI强化可提升高岭土在水处理和环境修复中的应用前景。     

镧(La)改性吸附材料脱除水体磷酸盐研究进展

磷素是水体富营养化的主要限制性因子,合适的除磷方法对控制水体富营养化具有重要意义。吸附法是一种经济、高效、操作简单的除磷方法,但如何选择合适的吸附材料是其应用的关键。La应用于常规吸附材料改性可提高其吸附磷酸盐的性能,同时可提高La利用效率。为进一步促进La改性吸附材料脱除水体磷酸盐的发展,本文归纳了国内外关于La改性吸附材料应用于水体磷酸盐脱除的相关研究,介绍了La改性吸附材料脱除磷酸盐的能力,分析了La改性吸附材料脱除磷酸盐的机理、主要影响因素以及解吸磷酸盐的特性。同时在此基础上提出未来应制备出对实际水体磷酸盐脱除高效和选择性强的La改性吸附材料,深入研究吸附材料制备机理以及脱除磷酸盐机理,探明吸附材料解吸磷酸盐的简单方法,并作出吸附材料解吸循环使用的经济效益评价。     

Adsorption of Eu(III), Th(IV), and U(VI) by mesoporous solid materials bearing sulfonic acid and sulfamic acid functionalities

ABSTRACT

SBA-15 mesoporous materials modified by sulfonic acid and sulfamic acid functionalities, abbreviated as SBA-15/SO₃H and SBA-15/NHSO₃H, were synthesized and applied for the removal–separation of Eu(III), Th(IV), and U(VI). SBA-15/NHSO₃H showed an excellent selectivity toward U(VI), while SBA-15/SO₃H was more efficient adsorbent for Eu(III) and Th(IV). It was found that in the presence of KNO₃ (1 mol L^?1), the separation of Eu(III)/Th(IV) from their mixtures is possible. The results of the sorption behavior indicated a high adsorption capacity toward U(VI) and Th(IV) ions (140.5 and 106.7 mg g^?1, respectively) and ultrafast kinetics (15 min) in Eu(III) adsorption.     

基于纳米材料的静态吸附脱硫进展

综述了近年来新型纳米吸附剂静态吸附脱除燃料油中二苯并噻吩（DBT）的作用机理及最新研究进展。重点分析了金属骨架材料（MOFs）、分子印迹聚合物（MIPs）、石墨烯基材料、活性炭基材料（AC）、介孔微孔材料等不同吸附剂的研究现状,从脱硫机理角度探讨不同改性方法对吸附脱硫效果的影响。通过比较这些吸附脱硫材料的优缺点,展望未来吸附脱硫材料的发展趋势和前景,为开发更优良的吸附剂用于吸附脱除DBT提供一些研究思路。文章指出吸附脱除燃料油中的DBT目前的主要问题是吸附剂的重复利用、与燃料油接触容易产生污染和吸附剂与燃料油分离过程中造成的损耗,这些短板也是吸附脱硫法大规模工业应用的主要障碍,因此吸附材料的选择、改性方法以及机理研究是吸附脱除DBT的主要研究方向。     

Performance of acrylic monomer based terpolymer/montmorillonite nanocomposite hydrogels for U(VI) removal from aqueous solutions

Acrylic monomer based terpolymer/montmorillonite nanocomposite hydrogels (NH-MMTs) synthesized using 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA), 2-acrylamido-2-methlypropane sulfonic acid (AMPS) and 2-hydroxyethyl methacrylate (HEMA) in the aqueous montmorillonite (MMT) suspension were employed as adsorbents for U(VI) removal from aqueous solutions. Adsorption efficiency of the NH-MMTs was strongly enhanced by increasing pH in the range of 3–6. Adsorption capacity of the NHs increased with the MMT weight ratio up to 1% and the complete removal of U(VI) from 1 mmol/L aqueous solutions was achieved by 2 g/L polymer but further increase of MMT up to 6% caused a gradual decrease in adsorption percentage up to 57%. Nearly 98% of U(VI) loaded on the adsorbents could be recovered by 0.1 M HNO₃. Consecutive adsorption/desorption cycles showed that the NH-MMTs are re-usable. Kinetic results were analyzed using Paterson's and Nernst Planck approximation's based on homogeneous solid phase diffusion (HSPD). Experimental data were fitted to equilibrium isotherm models, Langmuir, Freundlich, Dubinin–Radushkevich and Temkin. SEM, and FTIR analysis of bare and U(VI) loaded adsorbents were used to elucidate adsorption mechanisms. The results showed that the NH-MMTs tested in this study are very promising for the recovery of U(VI) from water.     

Potentiality of zirconium phosphate synthesized from zircon mineral for uptaking uranium

Zirconium phosphate (ZP), an inorganic ion exchanger, has been synthesized from zircon mineral, characterized, and used as a potential adsorbent for removing U(VI) from nitrate solution with varying background conditions including pH, shaking time, U(VI) initial concentrations, temperature and phase ratio. Batch results for uranium adsorption showed that the adsorption process reached steady-state condition within 30 min., and all the dissolved U(VI) was removed by ZP at pH 5, 298K and at (S/A) 0.1g/25 mL. Uranium adsorption process followed a traditional Langmuir adsorption isotherm, endothermic and spontaneous in nature which emphasized from thermodynamic data. The higher thermal stability of Zr-P amorphous material makes it applicable and efficient adsorbent for removing U(VI).     

超疏水三维多孔材料在乳化液油水分离中的应用研究进展

超疏水三维多孔材料基于润湿性和毛细作用可有效吸附回收水中浮油,近年来在乳化液的油水分离中也得到应用。本文重点从超疏水三维多孔材料的设计制备、对乳化液的油水分离效果、油滴在材料中的分离机制3个方面展开分析与评价。文中指出：材料设计制备方面,以海绵为主的多孔材料主要通过修饰低表面能物质和构建粗糙结构获得超亲油疏水性,疏水改性后的材料具备较高的油吸附容量（31～131g/g）。乳化液油水分离评价方面,超疏水三维多孔材料处理的对象多为O/W模型乳化液,油浓度低、表面活性剂浓度低、液滴粒径为微米级,少见对实际乳化液的处理;应用方式包括基于吸附作用的浸泡处理和吸附协同拦截作用的过滤处理两类;分析发现影响油水分离效果的关键是材料的孔径、表面疏水性和带电性。作用机制方面,疏水多孔材料吸附乳化油的作用过程仍停留在理论推测层面,主要观点为材料通过笼状孔道结构和疏水表面高效捕集和吸附油滴,油滴聚并破乳形成油层而被分离。虽然超疏水三维多孔材料在乳化液油水分离应用研究中取得了一定进展,但仍需探究其对实际废乳化液的适用性,设计开发连续分离设备以实现工程应用;结合原位观测、数值模拟、力学解析等方法解析油滴在多孔材料中的迁移转化规律和关键环节,以揭示其作用机制。     

Adsorption characteristics of toxic chromium(VI) from aqueous media onto nanosized silver nanoparticles-treated activated carbon

The present study reports the use of nanomaterial, e.g. Ag nanoparticles (AgNPs), immobilized activated carbon as an effective solid adsorbent for removal of toxic chromium(VI) from water. Chromium(VI) uptake was found favorable in acidic media at pH ≤ 3. Based on Langmuir model, monolayer adsorption capacities of chromium(VI) found equal 93.5 mg/g. The results fitted well with pseudo second-order and Langmuir models. The mechanism of adsorption was explored using the intra-particle diffusion model and the liquid-film model. Chromatographic separation of chromium(VI) was achieved. The AC-AgNPs was successfully recycled for five successive adsorption–desorption cycles indicating its high reusability.