螯合高分子对重金属处理的新动向(下)

二、螯合树脂对重金属的处理螯合树脂适于从废水中去除有害重金属。目前已广泛使用于垃圾焚烧厂,高等院校,科研单位,医院,工厂等大规模的重金属处理工艺中。下面仅它对水中的微量金属离子选择吸附特性及其在金属分离与回收领域中的应用作简要说明。     

螯合树脂的合成及其应用 第1报 海水及矿泉水中微量铀的富集和测定

测定海水或矿泉水中的微量重金属时,通常需预先应用共沉淀、液-液萃取、离子交换、蒸馏、共结晶,还原气化等分离、富集手段作前处理。然而这类方法或是操作烦琐冗长,或是回收效率不高。其中离子交换法虽需时较长,但操作简单,近年来为进一步改善树脂吸着性能,不断提出应用各种螯合树脂于此目的的报告,效果甚佳。螯合树脂系高分子母体中引入各种特征螯合基团作离子交换活性基团的一类吸着剂。现已报告用于吸着海水、工业污水等水样中微量铀的螯合树脂有多种,我们选择合成了含有如下活性基团的螯合树脂:     

萃淋树脂和螯合树脂在金属元素分离及试剂纯化中的应用

作者等就多年来在萃淋树脂及螯合树脂在金属元素分离及试剂纯化方面所取得的经验和成果作了总结。在萃淋树脂方面,概要地叙述了此类树脂的制备方法,其选择性及应用等内容。就螯合树脂方面几种突出实例,如Chelex 100树脂应用于从碱金属及碱土金属离子溶液中选择性地分离两价重金属;Amberlite 743硼选择性树脂用于选择性分离以BO33-或BF4-形式存在的硼(Ⅲ)离子;LZ 85树脂用于制备高纯度含钴试剂及353E树脂用于吸附分离金属离子与氰根形成的络合离子如Au(CN)4-、Ag(CN)2-等作了介绍。此外,还对应用阴离子交换树脂,如Dowex 1-X8,分离金属离子与氯离子生成的络阴离子,如[AuCl6]3-、[FeCl4]-等;对阳离子交换树脂用于制备高纯铀等特例作了简述。     

螯合树脂的合成及其应用——第2报 微量稀土元素分离特性的研究

应用螯合树脂分离稀土,国外已有这方面的报告。本文介绍应用含有偶氮胂I特征结构的Asl螯合树脂进行微量稀土总量和部分轻、中、重稀土La、Nd、Lu之间的分离和测定。研究了AsI螯合树脂分离稀土的特性和条件,测定了树脂对稀土的交换容量、分配系数及分离因素等参数。采用不同酸度和浓度的a-羟基异丁酸为洗脱剂,进行柱上分离稀土实验,2.6小时能定量洗脱分离微克量的La、Nd、Lu离子。     

多胺类螯合吸附剂对重金属离子吸附分离的研究进展?

综述了多胺类螯合吸附剂制备方法及其对微污染环境、复杂混合环境、高盐环境中重金属离子的特性吸附行为,重点总结了多胺类螯合吸附剂对重金属离子的吸附结合方式、高效分离机制及盐存在下的增强吸附机制,并进一步展望多胺类螯合吸附剂的应用前景、创新设计思路以及理论探索的研究方向,为拓宽多胺类螯合吸附剂在重金属离子无害化处理和资源化回收方面的应用范围,提供了理论和技术指导。     

401螯合树脂富集-原子吸收法测定海盐中微量重金属元素

海盐中微量重金属元素的测定,由于其主要成分氯化钠的影响,原子吸收法不能直接测定,通常必须进行预先分离和富集。目前一般采用APDC-MIBK或DDTC-MIBK体系萃取-原子吸收光谱法。近年来螯合树脂是分离碱金属、富集重金属元素有效手段之一,广泛用于测定海水中重金属离子。本文采用401螯合树脂富集-原子吸收法测定海盐中Cu、Zn、Co、Mn和Fe。     

多酚系螯合树脂的性能与应用

本文着重介绍一种多酚系螯合树脂的性能与应用。这种螯合树脂由于制造工艺简单，收率高，成本便宜，而且亲水性、耐久性及抗污染性好，在环境保护与有价物质资源回收等方面具有广阔的发展前景。     

典型含氮螯合树脂对铜镍离子吸附分离特性的研究

选择典型含氮螯合树脂IRC747作为高选择性吸附剂,系统研究其对单组份及双组份Cu(II)与Ni(II)的吸附分离行为。单组份静态实验结果表明,静态吸附等温线和动力学过程可以采用Langmuir方程和Lagergren二级动力学方程拟合。通过分析吸附作用前后树脂理化结构,推测螯合树脂与重金属离子的配位结合形式是以N原子和磷酸羟基上的O原子组成的五元环,并通过DFT理论模型进行了计算验证。在Cu(II)/Ni(II)双组份体系中,Cu(II)和Ni(II)的竞争吸附行为可用Extended Langmuir模型较好地描述。高浓度Ni(II)条件下,Cu(II)在IRC747树脂上有更好的吸附选择性能,在前230BV、245BV出水中,Ni(II)纯度分别高达100%、99.999%,经过简单的电解浓缩处理后可回收利用,并设计高纯镍制备工艺流程,为树脂在高纯金属制备方面提供了理论和技术上的支持。     

用新型胍基SG螯合树脂作为Au、Pt、Pd组试剂及ICP-AES同时测定的研究

本文首次提出用自己合成的、以胍基为功能团的螯合树脂作为Au、Pt、Pd的组试剂。并进行了各种条件的研究;如同时富集的最佳酸度及与其它贱金属离子分离的适宜酸度;时间对吸附影响;其它离子的干扰情况等。在大量各种贱金属存在下,作了AU.Pt、Pd的回收实验,并分析了阳极泥中的金、铂、钯含量,结果比较满意。     

糠醛系氮配位螯合树脂对贵金属元素的吸附性能

呋喃衍生物糠醛与二乙烯三胺反应制得了含有Schiff碱基,胺基及大共轭π键地的氮配位螯合树脂,应用电感耦合等离子体发射光谱研究了所得螯合树脂对贵金属元素Au,Pd,Pt,Rh,Ru,Ir及重金属元素Hg的吸附性能。结果表明,所得螯合树脂在较宽的酸度范围内能很好地吸附Au,Pd,Pt,Rh,Ru元素,具有优良的吸附选择性及较高的富集倍数,特别是对Au能达到定量吸附与洗脱,同时,在一定酸度条件下亦对Pt,Ir及Hg显示良好的吸附性能。     

The preparation of supported ionic liquids (SILs) and their application in rare metals separation

This review summarizes the preparation methods of support ionic liquids (SILs) and their applications in rare metals separation. The rare metals separation includes the recovery of high value metal ions and the removal of heavy metal ions from wastewater. SILs can be used as a kind of highly efficient multifunctional separation materials. The preparation methods of SILs include chemical immobilization technique in which ILs moieties are supported on solid supports via covalent bonds and physical immobilization techniques in which ILs are immobilized on solid supports via physical method such as simple im- pregnation, sol-gel method. According to the difference of solid supports, this review summarizes the application of polymer supported ionic liquids (P-SILs), silica based material supported ionic liquids (SM-SILs) and membrane supported ionic liq- uids (M-SILs) in rare metals separation. P-SILs and SM-SILs prepared by chemical method with N-methylimidazolium group can be used as highly efficient anion exchangers with high thermal stability and good chemical stability for adsorption of Cr(VI), Re(VII), Ce(IV). P-SILs prepared via simple impregnation afforded IL functionalized solvent impregnated resins (SIRs) which showed high separation efficiency and selectivity in the separation of rare earths(III) (REs(III)). SM-SILs prepared via sol-gel method with IL doped in the support as porogens or extractant show high removal efficiencies and excellent stability for the separation of RE(III), Cr(III) and Cr(VI). M-SILs with IL as plasticizer or carrier show improved stability, high perme- ability coefficient and good selectivity for Cr(VI) transport. Different supports and different supporting methods were suffi- ciently compared. Based on the different practical application, different forms of SILs can be prepared for separation of rare metals with high separation efficiency and selectivity.     

Rice Bran as an Excellent Sorbent for Heavy Metals from Aqueous Media, 2. Determination of Related Parameters

In part 2 of this report related parameters of the rice bran (as a sorbent of heavy metals) such as exchange capacity, distribution coefficients and isotherms, etc. were studied. The obtained results show that selectivity of the bran towards heavy metals such as Cu(II), Cd(II), Fe(III), Ni(II), Zn(II) and Pb(II) is very high. Also, distribution coefficients between aqueous solution and bran are more than 10⁴ so that all cations are completely adsorbed by the bran in relatively low concentrations. The principal advantages of this sorbent are as follows: high efficiency, very high exchanging speed, cheapness (in comparison with conventional resins), performance in batch and continuous conditions and producing no environmental pollution. The only disadvantage of the bran is low exchanging capacity for some elements (but for lead it is comparable to classical resins); however, it is able to eliminate heavy metals in mg/L level and above. On the other hand, due to low cost of bran and high cost of recovery of ion exchangers there is no necessity to recover the bran. Reproducibility of the proposed method in removal of heavy metals is excellent and the relative standard deviations for eight repeated removals for all cations with the exception of iron are less than 1%.     

氯甲基化苯乙烯-二乙烯苯共聚物的Friedel-Craft反应

氯甲基化苯乙烯-二乙烯苯共聚物在傅氏催化剂存在下与取代酚(芳香胺)反应可以得到一些含取代酚基的离子交换树脂。它们的物理化学性质和红外光谱分析证实了该类树脂的结构。溶剂的性质、催化剂的种类、用量、反应温度、时间、取代酚(芳香胺)的取代基位置、聚合物的含氯量和孔结构都对反应和副反应有明显的影响。这类离子交换树脂在重金属分离、脱色,特别在维生素和抗菌素的选择吸附等方面,都有十分重要的意义。     

Methode d'elution selective pour l'extraction des metaux lourds de l'eau de mer sur resine chelatante: A selective method of elution for the extraction of heavy metals from sea waters on a chelating resin

A selective method of elution for the extraction of heavy metals from sea waters on a chelating resin.The extraction of heavy metals in sea water with Chelex 100 prior to their determination by atomic absorption spectrometry (a.a.s.) with electrothermal atomization is discussed. Maximum retention of heavy metals is not obtained with the resin in the H⁺ form, because it is gradually transformed in contact with sea water by the fixation of alkali and alkaline-earth cations which are eluted simultaneously with the heavy metals and interfere during a.a.s. The separation of heavy metals is quantitative on Chelex 100 in the Ca²⁺ form; treatment with dilute acetic acid (1 + 99) eliminates the alkali and alkaline-earth metals fixed on the resin before elution or the heavy metals. Elution with 1 M nitric acid gives simultaneous and quantitative recovery of Cu, Pb, Ni, Zn, Cd and Co; intermediate elution with 0.01 M nitric acid isolates Zn, Cd and Co from Cu and Pb, which are subsequently eluted with 1 M nitric acid.     

Improved recovery of trace amounts of gold (III), palladium (II) and platinum (IV) from large amounts of associated base metals using anion-exchange resins

The adsorption and desorption behaviors of gold (III), palladium (II) and platinum (IV) were surveyed in column chromatographic systems consisting of one of the conventional anion-exchange resins of large ion-exchange capacity and dilute thiourea solutions. The noble metals were strongly adsorbed on the anion-exchange resins from dilute hydrochloric acid, while most base metals did not show any marked adsorbability. These facts made it possible to separate the noble metals from a large quantity of base metals such as Ag (I), Al (III), Co (II), Cu (II), Fe (III), Mn (II), Ni (II), Pb (II), and Zn (II). Although it used to be very difficult to desorb the noble metals from the resins used, the difficulty was easily overcome by use of dilute thiourea solutions as an eluant. In the present study, as little as 1.00 microg of the respective noble metals was quantitatively separated and recovered from as much as ca. 10 mg of a number of metals on a small column by elution with a small amount of dilute thiourea solution. The present systems should be applicable to the separation, concentration and recovery of traces of the noble metals from a number of base metals coexisting in a more extended range of amounts and ratios.     

超高交联吸附树脂柱色谱法分离提纯喜树碱及喜果甙

本文比较了所合成的8种大孔超高交联吸附树脂对喜树果提取液中喜树碱和喜果甙的吸附性能及柱层析分离效果。结果表明，经超高效联树脂的层析分离，喜树碱的质量分数可提高到约15％，喜果甙的质量分数可提高到约60％。     

Improved recovery of trace amounts of gold (III), palladium (II) and platinum (IV) from large amounts of associated base metals using anion-exchange resins

The adsorption and desorption behaviors of gold (III), palladium (II) and platinum (IV) were surveyed in column chromatographic systems consisting of one of the conventional anion-exchange resins of large ion-exchange capacity and dilute thiourea solutions. The noble metals were strongly adsorbed on the anion-exchange resins from dilute hydrochloric acid, while most base metals did not show any marked adsorbability. These facts made it possible to separate the noble metals from a large quantity of base metals such as Ag (I), Al (III), Co (II), Cu (II), ¶Fe (III), Mn (II), Ni (II), Pb (II), and Zn (II). Although it used to be very difficult to desorb the noble metals from the resins used, the difficulty was easily overcome by use of dilute thiourea solutions as an eluant. In the present study, as little as 1.00 μg of the respective noble metals was quantitatively separated and recovered from as much as ca. 10 mg of a number of metals on a small column by elution with a small amount of dilute thiourea solution. The present systems should be applicable to the separation, concentration and recovery of traces of the noble metals from a number of base metals coexisting in a more extended range of amounts and ratios.     

水体中重金属形态的毒性研究方法

以国内外近年来公开发表的科技文献为资料来源,总结了阳极溶出伏安法、离子交换树脂法,膜滤方法等各种化学方法测定水环境中重金属形态的结果与毒性的相关性,评价了各种方法的特点及优缺点,并提出了测定重金属毒性的新发展方向。参考文献共45篇。     

Comparison of some newly synthesized chemically modified Amberlite XAD-4 resins for the preconcentration and determination of trace elements by flow injection inductively coupled plasma-mass spectrometry (ICP-MS)

XAD copolymer resins may be functionalized with heavy metal ion-selective ligands either by covalent linkage to the polymer backbone or by impregnation. These resins may be tailored to be specific for certain heavy metals by adjusting the retention and elution parameters. For the synthesis of immobilized Amberlite XAD-4 copolymer resins that are expected to preconcentrate a number of transition and heavy metals, the Schiff base method was chosen. For this purpose the copolymer was nitrated, reduced to the corresponding amine and converted to the imine compounds via a Schiff base reaction using different organic aldehyde compounds. The interactions of 8 elements (Cd, Co, Cu, Mn, Ni, Pb, U and Zn) with the resins were qualitatively investigated. Optimal pH for retention was typically 6-8 for most resins although one could be used at pH 5 and elution was achieved using 0.1 M HNO3. The resins were characterized by FTIR, SEM and elemental analysis. It was demonstrated that the resins could be used to preconcentrate ultra-trace analytes from natural waters, and analysis of environmental certified reference materials using FI-ICP-MS showed good agreement with the certified values. Metal retention capacities were also calculated using a batch system and were found to compare favorably with other resins reported in the literature.     

Development of Resin Membranes as a Sensitive Indicator of Heavy Metal Toxicity in the Soil Environment

Abstract

Ion exchange resins in contact with soil can act as a sink for metal cations, thereby simulate the action of plant roots. Ion exchange resins in membrane form offer additional advantages in ease of use and handling. A procedure was developed to assess the bioavailability of four heavy metals Cd, Cr, Ni and Pb via direct in soil burial. A growth chamber experiment with three representative crops (oats, radish and lettuce) was set up to determine the phytotoxic levels of the four heavy metals. The critical levels varied widely from crop to crop, and soil to soil. Lettuce was most sensitive to high concentration of metals. The toxic effects are more pronounced on sandier textured soils.