Transferrin metalloprotein affinity metal chromatography

The metal transport protein transferrin, when immobilized to Sepharose, can serve as an affinity media for the selective removal and subsequent release of heavy metal ions from aqueous solution. The material is stable over the pH range of 2–10, is self-indicating for the binding of certain metal ions, and maintains its integrity towards metal-binding capacity for long periods of time. In one step heavy metal ion concentrations can be reduced by at least five orders of magnitude to, at most, part per billion levels. The findings here presented suggest a novel practical method for the decontamination and/or recovery of metals ions from very dilute solutions and represent the first efforts to extend the concept of affinity chromatography to metal ions.     

离子色谱测定垢样中的重金属离子

离子色谱作为一种新的分析技术,近年来发展迅速,在多领域得到广泛的应用.介绍了离子色谱在垢样分析中的应用.分析结果表明,离子色谱可同时测定多种组分,快速、灵敏而准确,取得了令人满意的结果.RSD为1.61%～4.11%,平均回收率93.4%～102.4%.     

Synthesis of sulfhydryl chitin and its adsorption properties for heavy metal ions

This article discusses the preparation of the water‐insoluble adsorbent sulfhydryl chitin (s‐chitin), by treatment of the chitin with sulfhydryl acetic acid in the presence of sulfuric acid as a catalyst. Its structure was confirmed by elemental analysis, FTIR spectra analysis and near‐IR spectra analysis. We also investigated the adsorption properties of sulfhydryl chitin for Cu^II, Cd^II, Pb^II, Cr^III, and Ni^II. Based on the research results of adsorption capacity, the effect of pH value on adsorption, adsorption kinetics experiments, and selective adsorption experiments were observed. It has been shown that the s‐chitin has much better adsorption for Pb^II, Cu^II, and Cd^II than chitin itself. The adsorption capacities of s‐chitin for Pb^II, Cu^II, and Cd^II were 108.3, 94.7, and 57.1 mg/g, respectively. It also had good adsorption properties for heavy metal ions. The adsorption capacities were also affected by the acidity of medium. The adsorbed Cu^II, Cd^II, and Pb^II could be eluted by diluted chlorhydric acid. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 151–155, 2000     

巯基改性纳米TiO2对痕量重金属离子吸附性能研究

钛酸丁酯(TBT)作为前驱物,采用溶胶-凝胶法进行共聚缩合,制备出巯基功能化TiO_2纳米材料,并将其运用于水体中痕量重金属的吸附富集研究。采用X射线粉末衍射仪、傅里叶红外、扫描电镜表征了吸附前后巯基化TiO_2纳米材料的物相组成、官能团、形貌变化。考察了初始pH值、时间和干扰离子对巯基化TiO_2纳米材料吸附重金属离子的影响。在优化吸附条件下借助火焰原子吸收分光光度计测定样品中重金属离子质量分数,该方法利用巯基化TiO_2纳米材料可有效富集水中的痕量Cd~(2+),Hg~(2+),Pb~(2+)离子,按Cd~(2+),Hg~(2+),Pb~(2+)在样品和洗脱液中的浓度计算,富集倍数可达100倍以上,对提高痕量Cd~(2+),Hg~(2+),Pb~(2+)检测的灵敏度和准确性起着重要作用。     

Enhanced adsorption properties of interpenetrating polymer network hydrogels for heavy metal ion removal

In this study, sequential interpenetrating polymer network (IPN) hydrogels based on poly(polyethylene glycol diacrylate) poly(PEGDA) and poly(methacrylic acid) (PMAA) were prepared with enhanced adsorption properties for heavy metal ion removal. The swelling behavior and mechanical property of the IPN hydrogels were characterized. It was found that swelling ratio increased, and mechanical strength decreased with the PMAA content in the IPN. The IPN hydrogels were used to remove heavy metal ions from aqueous solution under the non-competitive condition. The effects of pH values of the feed solution at the range of 3–5 and PMAA content in the IPN on the adsorption capacity were investigated. The results indicated that the adsorption capacity of the IPN hydrogels increased with the pH values and PMAA content in the IPN. Furthermore, the synergistic complexation of metal ions with two polymer networks in the IPN was found in the adsorption studies. Regeneration studies suggested that metal rebinding capacity of the IPN hydrogels did not change significantly through repeated applications compared with the first run. It was concluded that the poly(PEGDA)/PMAA hydrogels could be used as fast-responsive, high capacity, and renewable sorbent materials in heavy metal removing processes.     

Functionalized sepiolite for heavy metal ions adsorption

Surface modification of clays has become increasingly important due to the practical applications of clays such as fillers and adsorbents. The surface modification of sepiolite with [3-(2-aminoethylamino)propyl]trimethoxysilane has been employed. The modified sepiolite surface was investigated by FTIR, XRD and DTA/TG analysis. It was found that the chemical bonding takes place between the hydroxyl groups and/or oxygen atoms within the structure of sepiolite and methoxy groups of [3-(2-aminoethylamino)propyl]trimethoxysilane. The changes on electrokinetic properties of modified sepiolite particles were studied by measuring the zeta potential of particle as a function of metal concentration and equilibrium pH of solution. It was found that the zeta potential of the clay particles was always negative independent of the metal concentration in solution. This study also provides some evidence for the adsorption of metal ions on modified sepiolite. The adsorption of metal ions onto modified sepiolite has varied with the type of metal cations. The available basic nitrogen centers covalently bonded to the sepiolite skeleton were studied for Co(II), Cu(II), Mn(II), Zn(II), Fe(III) and Cd(II) adsorption from aqueous solutions. It was found that the amount of metal ion adsorbed onto modified sepiolite increases with increase in solution equilibrium pH and temperature, whereas it generally decreases with the ionic strength. The experimental data were correlated reasonably well by the Langmuir adsorption isotherm and the isotherm parameters (q_m and K) were calculated. The ability to adsorb the cations gave a capacity order of Zn(II) > Cu(II) ~ Co(II) > Fe(III) > Mn(II) > Cd(II) with affinities of 2.167×10⁻⁴, 1.870×10⁻⁴, 1.865×10⁻⁴, 1.193×10⁻⁴, 0.979×10⁻⁴ and 0.445×10⁻⁴ mol g⁻¹, respectively.     

亲和层析介质非特异性吸附的定量表征研究

针对亲和层析介质的非特异性吸附,基于脉冲响应法,建立了定量表征方法。以牛血清白蛋白、酵母发酵液和CHO细胞培养液作为典型杂质,考察了四种蛋白A亲和层析介质和两种基质微球,在不同pH和盐浓度条件下非特异性吸附。发现介质和基质对杂质均有不同程度的吸附,在酸性条件下非特异性吸附相对较强。对于不同料液,存在不同的杂质吸附机制,可通过静电、疏水作用或两者共同作用结合。两种介质和基质的比较结果表明,琼脂糖基介质的非特异性吸附主要依赖其基质微球与杂质间相互作用,而聚甲基丙烯酸酯基介质对杂质的吸附作用强于其基质微球。结果表明,本文建立的非特异性吸附定量表征方法切实可行,可用于量化表征介质非特异性吸附,探究相关作用机制,为介质研发提供新的分析方法和依据。     

赤泥吸附重金属离子性能及其机理研究进展

赤泥（RM）是铝土矿提取氧化铝时排放的工业废渣,对其进行改性后可作为一种低成本吸附剂有效吸附废水中的重金属离子。本文从赤泥的性质和组成进行讨论,分析赤泥吸附重金属离子的优势,总结酸改性、焙烧改性和复合改性对赤泥结构及重金属吸附性能的影响。在此基础上,阐述了赤泥吸附重金属离子的机理,列举了吸附热力学及吸附动力学模型。指出赤泥作为一种大宗工业废弃物,用作吸附剂吸附废水中的重金属离子,具有成本低、来源广泛等优点,同时可达到以废治废的目的,具有良好的应用前景。     

天然淀粉改性水处理剂的研制及其对重金属、染料的吸附

重金属及染料是环境水体中危害极大的两类污染物,将天然淀粉进行交联、接枝改性制备的二硫代氨基甲酸基(DTC)淀粉对这两类污染物具有极强的吸附能力,其吸附重金属后的残留物安全、无毒,且可多次再生重复利用。对吸附产物的表面和结构分析表明,吸附作用主要发生在淀粉颗粒的表面,通过螯合作用吸附重金属离子,通过静电作用吸附染料分子。采用酶解、溶胶-凝胶等方法对天然淀粉进行预处理可显著提高饱和吸附量。     

The heavy metal adsorption characteristics on metakaolin-based geopolymer

Since porous materials often function as adsorbents, this study chose to investigate the adsorption of heavy metals by geopolymers. The geopolymer was made by condensing a mixture of metakaolin and alkali solution at a fixed ratio at room temperature and then pre-crashed to a fixed-radius size. This paper examined the adsorption efficiency of the geopolymer for different heavy metals (i.e., Pb²⁺, Cu²⁺, Cr³⁺, and Cd²⁺) in aqueous solutions under discrete experimental parameters. The experimental results verified that the geopolymer could adsorb heavy metals. Of the metals tested, optimal adsorption with the implementation of the geopolymer occurred with Pb²⁺. The data fit both the pseudo-second-order and the Langmuir equations. This discovery may facilitate the development of optimized procedures for wastewater treatment, thus providing an alternative solution to environmental damages caused by heavy metal pollutants.     

Carbon nanotube filter for heavy metal ion adsorption

This study investigated carbon nanotube filtration technology using catalyst particles supported on silicalite-1–biomorphic carbon materials (BCMs). Aqueous solutions of Mn(II), Cu(II), Cr(III), Cd(II), and Pb(II) were used to test the efficiency of heavy metal ions removal. Carbon nanotubes (CNTs) were synthesized and grown on BCMs by the chemical vapor deposition method catalyzed with the catalyst (Co, Fe, and Ni). The synthesized CNTs with Co– and Fe– nanoparticles were typically multi-walled carbon nanotubes, and they showed good crystallinity (I_D/I_G = 1.05) and yield of (11.10 and 8.86) %. The removal efficiency of Mn(II), Cu(II), Cr(III), Cd(II), and Pb(II) ions using Co-catalyzed CNT filter was 97.57%, 98.01%, 97.89%, 97.42%, and 99.99%, respectively.     

活性炭对重金属离子的吸附研究

研究了活性炭分别对铅、镉、铜及锌离子的吸附作用,研究了pH值、温度及活性炭的投加量等因素对吸附效果的影响。结果表明,当pH〉5时对四种离子的去除率均达到98％以上,能达到很好的吸附。低温有利于吸附的进行。随着活性炭的增加．重金属离子的去除率增加．而且铜离子的活性炭最佳用量是0．3000g．铅、镉和锌的活性炭最佳用量均为1．000g。随着吸附时间的增加,去除率上升。铜、铅、镉和锌离子的吸附平衡时间分别为3．5h、1h、1．5h和1．5h。铜离子的吸附符合Langmuir等温模式,而锌、铅和镉离子的吸附符合Freundlich等温模式。     

吸附法处理重金属废水的研究进展

重金属废水是对环境污染最严重和对人类危害最大的工业废水之一,吸附法作为一种重要的处理重金属废水的方法已经得到广泛应用。本文介绍了近年来利用吸附法处理重金属废水的研究进展。根据吸附机理将吸附剂吸附重金属的方法分为化学吸附和物理吸附两大类,并对其研究现状进行了介绍。指出温度、吸附剂的用量、吸附时间、重金属离子的初始浓度以及溶液的pH值等吸附条件对吸附剂吸附重金属的影响,介绍了活性炭、沸石、壳聚糖、膨润土、生物吸附剂、废弃农作物、纳米材料、离子交换树脂、高分子吸附材料等9种吸附剂处理重金属废水的研究进展,同时对吸附法处理重金属废水的发展方向进行了展望。     

《工业用水与废水》2015年第46卷总目次

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金属亲和膜色谱法纯化木瓜蛋白酶条件优化

建立了一种快速、简便的分离木瓜蛋白酶的方法。尼龙膜经壳聚糖改性后,以金属镍离子N i2+为配基制备了一种新型的蛋白质分离材料,并将该亲和膜应用于木瓜蛋白酶的分离纯化,在对洗脱液、上样速度、洗脱速度、洗脱液的pH值和洗脱液的离子强度进行优化的基础上,成功地分离纯化出木瓜蛋白酶,纯化倍数为20.59倍。     

气相色谱法测定环己酮中的微量重组分

应用GC-2014气相色谱仪,建立了气相色谱法测定环己酮中微量重组分的分析方法。结果表明:采用中等极性的色谱柱OV-1701,30 m×0.32 mm×0.5μm,载气为氮气,在柱温初始温度为100℃,程序升温至120℃,柱流速为1.0 mL/min的条件下进行色谱分析,氢火焰离子检测器检测,外标法定量,环己酮中的2-甲基环己酮、3-甲基环己酮,4-甲基环己酮等微量重组分能得到很好的分离,方法的回收率为99.8%~100.7%,相对标准偏差为0.40%~1.10%。     

氯化锌与高锰酸钾混合改性甘蔗渣重金属吸附剂的研究

本研究以甘蔗渣为原料,用Zn Cl2与KMn O4混合对其进行改性,通过其对水中C(rⅥ)的去除率来考察其吸附性能,并对改性甘蔗渣进行了SEM表征。结果表明:甘蔗渣用量为2g,甘蔗渣的尺寸为90目,KMn O4用量为1g、改性温度为50℃、改性时间为8h,Zn Cl12浓度为100g·L-时,改性甘蔗渣吸附重金属六价铬的去除率达到最大值为87.1%,吸附量为10.5mg·g-1。改性甘蔗渣的SEM表征显示:表面出现微孔结构,比表面积增大,提高了改性甘蔗渣的吸附能力。     

重金属离子吸附用微凝胶研究新进展

微凝胶聚合物网络中易于引入能够与重金属离子螯合或络合的功能基团,且比表面积大,对重金属离子具有较快的吸附速率,因此,微凝胶在重金属离子的去除方面具有广阔的应用前景。本文介绍了重金属离子吸附用微凝胶研究新进展,重点回顾了基于羧基、氨基、磺酸基、羟基及巯基等多官能团化合物与重金属离子通过静电相互作用形成稳定络合物的微凝胶用于重金属离子的吸附,离子印迹型微凝胶用于重金属离子的吸附,以及基于冠醚环（苯并-18-冠-6醚）与Pb²⁺离子通过超分子主-客体识别作用形成稳定络合物的微凝胶用于重金属离子的吸附;描述了这三类微凝胶对重金属离子的吸附性能、优点、用途等;指出了这三类微凝胶适用于不同场合下重金属离子的吸附。     

Preparation of mercaptoethylated graft fibers for adsorption of heavy metal ions

Various kinds of mercaptoethylated graft fibers were prepared and the abilities to adsorb the heavy metal ions were studied. 2-Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and vinyl acetate were graft-copolymerized by irradiation onto five kinds of synthetic fibers and two kinds of foam polymers. Preirradiation at low temperature was far more effective for grafting than simultaneous irradiation. The mercaptoethylation was carried out in the solution or in the vapor of ethylene sulfide onto the graft fibers treated with alkali. The mercaptoethylated graft fibers showed particular affinity for Hg and Ag ions. A few of the adsorption phenomena were pursued by flow experiment of the ionic solution through a column. The preliminary reduction of the mercaptoethylated graft fibers enhanced the capacity of adsorbing to three times that of the unreduced fibers. Effects of flow rate, pH, temperature, and concentration of Hg ion on the integrated adsorbed amount were also investigated.