Sorption Behavior of Dowex PSR-2 and Dowex PSR-3 Resins of Different Structures for Metal(II) Removal

The sorption behavior of palladium(II) (Pd(II)) onto strongly basic anion exchange Dowex resins was studied depending on the concentration of hydrochloric acid (0.1–6.0 M HCl–100 mg Pd(II)/L), concentration of hydrochloric and nitric(V) acids (0.1–0.9 M HCl–0.9–0.1 M HNO₃–100 mg Pd(II)/L), and the time of contact of the solution with the anion exchange resin in the batch mode. Similar research was carried out also for the base metal ions such as cobalt(II) (Co(II)), copper(II) (Cu(II)), nickel(II) (Ni(II)), and zinc(II) (Zn(II)). The sorption process was also examined depending on the initial Pd(II) concentration, agitation rate, bead size distribution, and temperature. Pd(II) sorption was also checked in the column mode. The equilibrium and kinetic characteristics of the sorption of Pd(II) with the Dowex PSR-2 and Dowex PSR-3 anion exchange resins were determined. The possibilities of Pd(II) elution and reuse using the batch method was exploited. Pd(II) and Zn(II) sorption on the Dowex resins is time and concentration of acids dependent. Evaluating the determination coefficients, the kinetic studies showed that the pseudo-second-order equation and the Langmuir model described the data more appropriately than others. The maximum sorption capacity was 165.15 mg Pd(II)/g for Dowex PSR-2 and 184.39 mg Pd(II)/g for Dowex PSR-3. Dowex resins give quantitative Pd(II) removal from diluted acidic solutions.     

载铜树脂处理高含盐氨氮废水的性能

针对高含盐氨氮废水，选择具有不同功能基团的树脂为载体，进行负载Cu2+改性制得载铜树脂并对其处理高含盐氨氮废水的性能进行研究。在筛选出最佳载铜树脂的基础上，研究pH及Na+浓度、树脂投加量、反应时间对载铜树脂处理高含盐氨氮废水效果的影响，通过对吸附氨氮前后的载铜树脂进行SEM和EDS表征分析并构建吸附动力学模型以进一步探究配位吸附的过程。结果表明，Cu2+可与螯合树脂D751稳定结合且在宽pH值下均表现出耐盐性和良好的氨氮吸附效果；在室温(25℃)、pH=11及Na+浓度4 g/L、树脂投加量8 g/L、反应时间60 min的条件下，D751载铜树脂对氨氮的去除率为34.8%。D751载铜树脂吸附氨氮后其表面出现明显的晶状结构物质，该物质可能为铜氨络合物。D751载铜树脂对高含盐氨氮的吸附符合准二级动力学模型。     

Kinetics and Equilibrium Studies for the Removal of Cobalt,Manganese, and Silver in Ethanol using Dowex 50W-x8 Cation Exchange Resin

Organic solvents such as ethanol, find a wide range of applications in fuel, pharmaceutical industries, food industries, and paint formulations, among others. The removal of Ag(I), Co(II), and Mn(II) ions in ethanol by cation exchange resin, Dowex 50W-x8, was investigated. The adsorption characteristics of metal ions onto Dowex 50W-x8 resin were described by Langmuir isotherms. The maximum sorption exchange capacities at 298 K were obtained as 47.4 mg g^?1, 52.6 mg g^?1, and 58.5 mg g^?1 for Ag(I), Co(II), and Mn(II), respectively. The data was also fitted to Temkin and Dubinin-Radushkevich adsorption isotherm models to evaluate other adsorption properties. The ion exchange of silver, cobalt, and manganese on cation exchange resin followed pseudo-second-order kinetics, and the intraparticle diffusion was rate-determining step. The thermodynamic parameters indicated that the sorption of metal ions onto Dowex 50W-x8 resin was spontaneous (negative ΔG°) and endothermic in nature (positive ΔH°) implying that the adsorption capacity increased with increasing temperature. The resin can be regenerated by eluting metal ions with 3.0 mol L^?1 HNO₃ followed by washing it with 10 mL of Millipore water and 10 mL of 2.0 M NaOH, respectively. The proposed method was applied for metal ion removal in real ethanol samples.     

Dowex50W-X树脂吸附硫酸溶液中的锶

In this study,strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated.Among these resins,Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions.The effect of pH,contact time,mass of resin,temperature,and concentration of interfering ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process.The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models.The results indicated that the pseudo-second order kinetic model was more appropriate than the other one.Moreover,the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data.     

Batch adsorptive removal of copper ions in aqueous solutions by ion exchange resins: 1200H and IRN97H

The removal of copper from aqueous solution by ion exchange resins, such as 1200H and IRN97H, is described. Effect of initial metal ion concentration, agitation time and pH on adsorption capacities of ion exchange resins was investigated in a batch mode. The adsorption process, which is pH dependent, shows maximum removal of copper in the pH range 2–7 for an initial copper concentration of 10 mg/L. The experimental data have been analyzed by using the Freundlich, Langmuir, Redlich-Peterson, Temkin and Dubinin-Radushkevich isotherm models. The batch sorption kinetics have been tested for a first-order, pseudo-first order and pseudo-second order kinetic reaction models. The rate constants of adsorption for all these kinetic models have been calculated. Results showed that the intraparticle diffusion and initial sorption into resins of Cu(II) in the ion exchange resins was the main rate limiting step. The uptake of copper by the ion exchange resins was reversible and thus has good potential for the removal/recovery of copper from aqueous solutions. We conclude that such ion exchange resins can be used for the efficient removal of copper from water and wastewater. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.     

Efficient Removal of Hg(II) by Polymer-Supported Hydrated Metal Oxides from Aqueous Solution

Chelating PS-EDTA resins modified by metal (Fe, Al, and Zr) oxides were used as adsorbents to remove Hg(II) from aqueous solutions. The modified resins were characterized by BET, FTIR, and XPS. The amino, carboxylate, and the metal oxides on resins exhibited a synergistic effect for Hg(II) removal. It was observed that the modification of PS-EDTA resin not only increased the adsorption of Hg(II) but also accelerated the adsorption rate of Hg(II). The equilibrium data of Hg(II) were best described by the Freundlich isotherm, and the kinetics were found to follow the pseudo-second-order kinetic model. Also, thermodynamic parameters showed that Hg(II) adsorption was endothermic and spontaneous in nature. The increasing the concentration (0.1–2.0 g/L) of NaNO₃ in Hg(II) solution did not affect the adsorption of Hg(II). Moreover, the competitive adsorption indicated that the modified resins had higher selectivity towards Hg(II) over Cd(II), Pb(II), Zn(II), or Cu(II) in a binary system. All of the above results indicated that the modified resin was an efficient and reusable adsorbent for Hg(II) removal due to its simple preparation, high adsorption capacity, fast adsorption rate, ionic strength independence, high selectivity, and good reusability. These properties are of potential application in the fixed-bed continuous-flow column for Hg(II) removal from wastewaters.     

The conditions of cationic exchange with the use of recycling polystyrene derivative,the product of sulfonation by silica sulfuric acid

Growing amount of waste plastics has become an environmental problem on a global scale. This study presents an investigation of the conditions of cleaning water from heavy metal ions using chemically recycled polystyrene. To get effective ion exchangers, the sulfonation of virgin polystyrene and expanded polystyrene wastes were obtained using silica sulfuric acid. As it turned out, the use of this solid sulfonating agent simplifies the separation of the polymeric product from the acid and the solvent in comparison to conventional sulfonation methods. The ion exchange behavior of copper and zinc cations in the yielded sulfonated derivatives of polystyrene was studied. Batch shaking adsorption experiments depending on contact time, pH, temperature, and dosage of adsorbate were carried out. The stability of resin to cyclical adsorption and regeneration (column experiment) was also investigated. We report that resins have a high adsorption efficiency with total ion exchange capacity (IEC) about 2.6 meq g^?1, which drops with decreasing pH owing to competition between protons H⁺ and metal cations, whereas with the increasing resin doses the removal of cations rises for a constant initial metal concentration. The speed of cation exchange for yielded adsorbents was even better than for commercial resins. After 360 cyclical adsorption and regeneration in column, resin had working IEC of about 2.3 meq g^?1. The study shows that cation exchange resin from polystyrene wastes can be used as an efficient adsorbent for the removal of heavy metal ions from water. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Copper recovery from nickel laterite with high-iron content: A continuous process from mining waste

The waste product from the hydrometallurgical processing of nickel laterite ores can contain valuable metals, making their recovery economically viable. However, the high-impurities content, mainly iron, makes the process technically unfeasible. As a result, the separation of metals from the leach solution must be selective. Among the techniques available, the use of chelating resin is advantageous due to its selectivity and low energy consumption. Among the commercial chelating resins available, Dowex XUS 43605 has been shown to be highly selective for copper and can be used with a high impurities content. Although there are studies on the use of Dowex XUS 43605, none have evaluated a high impurities content and modelled a continuous process. For this reason, the aim of this work was to investigate copper recovery by a continuous process. The Dowex XUS 43605 chelating resin with HPPA functional group was used in ion-exchange experiments. Column experiments were performed in two steps: loading (to recover copper) and elution (to obtain a copper-rich solution). The removal of iron and the subsequent collection of copper were possible in a precipitation step using CaCO₃. The results showed that the solution obtained from elution had a copper concentration that was 10 times higher than in the loading. All of the iron was removed from the elution solution at pH 3.5 with 5% of copper losses. Copper precipitation was possible at pH 5.5. From the results obtained, a proposed flowsheet for recovering copper was suggested.     

FeCl3和十六烷基三甲基溴化铵改性赤泥对水中铜离子的吸附性能和机理

含铜废水主要来自电镀、有色冶炼、有色金属矿山开采、染料生产等过程。因Cu(Ⅱ)具有高毒性和生物富集性，严重威胁生态环境和人类健康。利用浓盐酸、三氯化铁（FeCl₃）、十六烷基三甲基溴化铵（CTAB）依次对拜耳法赤泥（RM）进行处理、改性，制备出了一种去除率高、吸附量大、吸附效果好的重金属离子吸附剂。通过SEM、TEM、XRD、BET、元素分析、FTIR、热重分析等手段对其进行表征，并探究溶液pH、吸附剂投加量以及吸附温度等条件对水溶液中Cu(Ⅱ)吸附效果的影响。结果表明：酸浸赤泥（RM-HCl）比表面积比RM增大20倍，经过FeCl₃和CTAB改性后赤泥表面负载了大量羟基氧化铁（FeOOH）并且改善了吸附材料的表面性质，提高了吸附材料与Cu(Ⅱ)之间的亲和力和单层吸附能力。综合改性赤泥（FeCl₃/CTAB/RM）对铜的吸附时间在100min达到平衡，其最佳吸附pH为6、最佳吸附剂投加量为2g/L、饱和吸附量为221mg/g。吸附过程较好地符合准二级动力学模型和Langmuir吸附等温模型，热力学数据说明该吸附是吸热、自发的过程。吸附机理主要是FeCl₃/CTAB/RM表面的羟基（Si-OH、α-FeOOH和β-FeOOH）以及掺杂的氯原子和表面活性剂，通过物理吸附（微胶束、静电引力）和化学吸附（离子交换、氢键）有效地去除Cu(Ⅱ)离子。     

Heavy metals adsorption on some iminodiacetate chelating resins as a function of the adsorption parameters

The adsorption properties of some novel chelating resins (CRs) bearing iminodiacetate groups for removal of heavy metal ions like: Cu(II), Co(II) and Ni(II) from aqueous solutions comparative with the commercial resin Amberlite IRC-748 have been studied in this work by a batch equilibrium technique. Quantitative analysis for adsorption was conducted using UV–vis spectroscopy to investigate the kinetics, adsorption isotherm and thermodynamics of the removal process considering equilibration time, pH, metal ion concentration and temperature as controlling parameters. The metal adsorption capacities, at pH 5, were in the order Cu(II) > Ni(II) > Co(II), for both the CR with 10 wt.% DVB (CR-10) and the commercial resin Amberlite IRC-748. The adsorption capacities on CR-10 were higher for Ni(II) and Co(II) ions, but lower for Cu(II) ions compared with Amberlite IRC-748. Both Freundlich and Langmuir isotherms well fitted on the adsorption results of Cu(II), Ni(II) and Co(II) ions on all iminodiacetate resins.     

Separation and Recovery of Silver(I) Ions from Base Metal Ions by Thiourea- or Urea-Formaldehyde Chelating Resin

Abstract

In the present work, thiourea-formaldehyde (TF) and urea-formaldehyde (UF) chelating resins have been synthesized and they have been used in the adsorptions of Ag(I), Cu(II), and Zn(II) metal ions by batch and column methods. The effect of initial acidity of Ag(I) solution and the adsorption capacities of TF and UF resins by batch method and the separation of Ag(I) ions from Cu(II) and Zn(II) base metal ions by the column method were examined experimentally. The adsorption capacities of TF and UF resins were found as 58.14 and 47.39 mg Ag(I)/g by batch method and 30.7 and 4.66 mg Ag(I)/g, 0.80 and 0.121 mg Cu(II)/g, and under 0.002 mg Zn(II)/g by the column method, respectively. It was found that Ag(I) ions showed higher affinity towards TF resin than UF resin, compared with Cu(II) or Zn(II) ions, and Ag(I) could be separated more effectively by TF resin from Cu(II)and Zn(II) ions.     

NaOH改性棉花秸秆对Cu~(2+)、Pb~(2+)的吸附研究

采用NaOH处理过的棉花秸秆去除废水中的Pb2+和Cu2+,探究不同因素对Pb2+、Cu2+的吸附效果的影响,确定最佳吸附工艺条件。结果表明,Pb2+最佳吸附条件为:投加量为33.33 g/L,振荡时间为110 min,吸附温度为25℃,溶液初始浓度为15 mg/L,pH值为5.0,去除率达92%;对Cu2+的最佳吸附条件为:投加量26.67 g/L,振荡时间为110 min,吸附温度为55℃,溶液初始浓度为15 mg/L,pH值为5.0,去除率达90.4%。     

Removal of Copper and Lead from Aqueous Solution by Adsorption onto Cross-Linked Chitosan/Montmorillonite Nanocomposites in the Presence of Hydroxyl–Aluminum Oligomeric Cations: Equilibrium,Kinetic, and Thermodynamic Studies

Adsorption removal of Cu (II) and Pb (II) on cross-linked chitosan/Al₁₃-pillared montmorillonite (CCPM) was examined in solutions. The chitosan dosage was drastically reduced in the new nanocomposite, which is made from the treated clay (Al₁₃-pillared montmorillonite). Several important parameters that influenced the adsorption of Cu (II) and Pb (II) ions, such as cross-linked chitosan-to-clay ratio, pH, temperature, initial concentration, dosage, and contact time effect, were systematically investigated. Result showed that in the nanocomposite with cross-linked chitosan-to-clay ratio of 0.45:1, the maximum removal efficiencies of Cu (II) [pH 6.5, dosage 10 g/L, initial Cu (II) concentration 100 mg/L, contact time 2 h, 298 K] and Pb (II) [pH 6.0, dosage 5 g/L, initial Pb (II) concentration 100 mg/L, contact time 2 h, 298 K] were 96.0% and 99.5%, respectively. Kinetic and isotherm studies have indicated that the adsorption process of Cu (II) or Pb (II) nanocomposites was better fitted by the pseudo-second-order equation and the Freundlich equation, with chemical adsorptions as the rate-limiting step. The metal–ion affinity to the functional groups of CCPM followed the order Pb (II) > Cu (II). The thermodynamic parameters ΔH and ΔS values showed that the sorption process of Cu (II) or Pb (II) was spontaneous (ΔG < 0), was endothermic (ΔH < 0), and had decreased entropy (ΔS < 0). HNO₃ (0.1 M) could be a good desorbent in the recovery of metal ions after adsorption and regeneration of the adsorbent.     

大孔吸附树脂XAD-4对聚乙二醇的吸附性能

以大孔吸附树脂XAD-4为吸附剂,采用静态平衡吸附法吸附模拟聚乙二醇(PEG)废水,考察了初始pH值、吸附时间、吸附剂投加量和温度等因素对PEG去除效果的影响. 结果表明,pH值对吸附过程的影响可忽略不计. 当XAD-4树脂投加量为0.3 g/L时,PEG去除率可达89%,平衡吸附量Qe=59.95 mg/g. PEG在XAD-4树脂表面上均一分布,Langmuir, Dubinin-Radushkevich和Sips模型可较好地模拟其等温吸附过程. 不同温度下均为自发的放热吸附过程. 动态吸附数据符合拟二级动力学方程.     

Preparation and characterization of an IPN type chelating resin containing amino and carboxyl groups for removal of Cu(II) from aqueous solutions

A novel IPN type chelating resin, amino-functionalized poly (glycidyl methacrylate)/poly (acrylic acid), (pGMA/pAA), was synthesized by a combination of serial reactions including, conventional radical polymerization, amination and photopolymerization. To assess the efficacy and characteristics of the resin in removal of Cu (II), batch adsorption experiments were carried out, and the effects of different parameters such as contact time, adsorbent dosage, initial metal ion concentration, temperature, and pH on the adsorption process were investigated. The results showed that 0.5 g/L dosage and pH 5 are the optimum values to achieve the maximum adsorption capacity and the adsorption kinetic of Cu (II) was well represented by pseudo-second-order kinetic model. In addition, it was found that the adsorption was mainly controlled by the film diffusion mechanism, along with a considerable contribution of the intra-particle diffusion mechanism, and Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models can be used for interpreting the adsorption process. Moreover, FT-IR analysis results and the mean free energies of adsorption clearly indicate that the ion exchange and chelation mechanisms took place as dominating mechanisms simultaneously during the adsorption process. It was also found to be that IPN resin could be used at least four times without losing its original activity.     

大孔吸附树脂对芦丁的吸附实验探索

以芦丁为吸附质,考察不同种类的大孔吸附树脂对芦丁水溶液的吸附、树脂活化处理方法、吸附实验的实施方法和树脂的最佳用量。结果表明,最佳操作条件如下:树脂活化时间5 d,吸附前用95%乙醇浸泡会明显增加吸附量,吸附实验增重物确定为玻璃珠子,树脂适宜用量约为1.20000 g。并做了6种大孔树脂在芦丁水溶液中的吸附等温线,得出大孔树脂在芦丁中的吸附,会发生毛细下降效应,通过对大孔树脂的物化参数分析,发现大孔树脂的比表面积并不是决定吸附量的最主要因素,而由大孔树脂的物化参数以及溶剂的性质等协同作用决定。     

一种高吸水树脂对电镀废水中铜离子的吸附研究

以废弃聚乙烯(PE)塑料与具有亲水性基团的丙烯酸(AA)及其盐接枝共聚合成一种高吸水性树脂,并将所得高吸水树脂用于溶液中Cu2+的吸附。通过分光光度法研究了树脂去除水溶液中Cu2+的情况,考察了起始pH、树脂用量、金属离子起始浓度和吸附时间对金属离子去除率的影响。结果表明,该树脂对Cu2+具有较强的吸附性能。树脂初期吸附速率大,吸附达到平衡时的接触时间为30 min。当溶液pH为7.0,Cu2+初始浓度为25 mg/L,树脂用量在8 g/L时,树脂对Cu2+的去除率可达95.0%以上。     

交联壳聚糖树脂的制备及对Cr（Ⅵ）的吸附研究

以壳聚糖为原料,通过反相悬浮交联法制备交联壳聚糖树脂,将其用于吸附Cr（Ⅵ）,考察了吸附时间、溶液pH、树脂用量、Cr（Ⅵ）的初始浓度和介质等因素对吸附的影响。实验结果表明,吸附平衡时间为20 min,最佳吸附pH为6.0,最佳用量为10 mg,Cr（Ⅵ）起始浓度为6 mg/mL,介质对吸附的影响大小顺序：Cu2＋〉Na＋。重复使用3次,再生性能好。     

螯合树脂对铜离子的吸附动力学和热力学

针对以谷氨酰胺-铜(II)配合物为供体酶法制备茶氨酸体系,研究了D401螯合树脂对Cu2+的吸附,探讨了吸附过程的热力学和动力学,通过红外光谱鉴定了树脂的配位结构. 结果表明,树脂吸附量随离子浓度和温度升高而增加,当pH为5.6时吸附量最大,达1.887 mmol/g. 不同温度下Langmuir方程均呈现很好的拟合度. 热力学平衡方程计算得DG<0, DH=21.5 kJ/mol, DS>0,表明该吸附过程是自发的、吸热、熵增加的过程. 动力学研究表明,该过程符合准二级动力学模型,吸附反应速率由颗粒扩散和液膜扩散共同控制. 该树脂在较宽的pH范围内对Cu2+具有很好的选择吸附性,可用于酶转化茶氨酸体系中Cu2+的去除.     

Selective adsorption of the gold–cyanide complex from waste rinse water using Dowex 21K XLT resin

The Dowex 21K XLT resin which is a strong basic resin was used to selectively adsorb gold–cyanide complex only, in the actual waste rinse water which coexisted with lead–cyanide complexes. The existence of gold–cyanide complex on the surface of the Dowex 21K XLT resin was proved by SEM and EDX analysis. The maximum removal efficiency value for gold–cyanide complex was about 93% for 10 g/L of resin concentration while adsorption for lead–cyanide complexes did not almost happen at pH 13. The adsorption capacity of Dowex 21K XLT resin for gold and lead–cyanide complexes was about 32 and 0.8 mg/g-dry mass, respectively. Also, most of adsorption process for gold–cyanide complex was completed within 1 h. The exothermic nature of gold–cyanide complex adsorption onto the Dowex 21K XLT resin was revealed because the removal efficiency for gold–cyanide somewhat decreased as temperature increased. It was concluded that the Dowex 21K XLT resin, which has excellent selectivity to gold–cyanide complex, can be applied to the recovery system for gold–cyanide complex in actual waste rinse water.