阴离子交换树脂对磺基水杨酸的吸附解吸性能

用阴离子交换树脂(D201)吸附的方法研究了磺基水杨酸的富集及回收。测定了溶液的pH值、温度、吸附时间等因素对吸附的影响,探讨了吸附的热力学和动力学特性。结果表明:D201树脂在pH=2—11时,吸附能力最好,等温吸附服从Freundlich经验式,吸附动力学符合Lagergren一级速率方程,颗粒内扩散是速率控制步骤之一,膜扩散也共同影响着吸附过程。在295—313 K条件下,磺基水杨酸吸附质量分数为380—420 mg/g的吸附焓变为-13.73—-8.422 kJ/mol,自由能变为-19.89—-21.45 kJ/mol,吸附熵变为20.88—41.62 J/(K.mol),吸附速率常数为0.025 3—0.056 5 min-1,吸附活化能为34.04 kJ/mol。315 K下用质量分数10%NaCl+2%NaOH溶液可定量洗脱,洗脱率达99%。     

D201树脂对水杨酸的吸附热力学与动力学

以D201大孔阴离子交换树脂对水溶液中水杨酸的吸附热力学和动力学特性进行了研究。结果表明:在pH=3~12时,吸附能力最好。等温吸附服从Freundlich经验式。在298~318K条件下,水杨酸吸附量为100~120 mg/g的吸附焓变为-7.38~-5.00 kJ/mol、自由能变为-8.46~-9.37 kJ/mol、吸附熵变为3.62~13.74 J/(K.mol)。吸附动力学符合Lagergren一级速率方程,吸附速率常数为0.0472~0.124/min,吸附活化能为38.1 kJ/mol。颗粒内扩散是速率控制步骤之一,膜扩散也共同影响着吸附过程。303 K下用5%NaCl+2%NaOH溶液可定量洗脱,洗脱率达99%。     

离子交换树脂吸附苯酚的性能研究

研究了717强碱阴离子交换树脂对苯酚的吸附性能。结果表明,在pH=10~13时,吸附能力最好。等温吸附符合Freundlich和Langmuir经验式。在293~313 K条件下,苯酚吸附量为220~260 mg/g的吸附焓变为-13.69~-12.02 kJ/mol,吸附自由能变为-7.02~-7.21 kJ/mol,吸附熵变为-22.76~-15.37 J/(K.mol)。吸附动力学符合Lagergren准二级速率方程,吸附速率常数为8.5×10-4~2.74×10-3g/(mg.min),吸附活化能为44.1 kJ/mol。303 K下其静态累积饱和吸附容量为399.8 mg/g(4.253 mmol/g)。用0.05 mol/L HCl溶液能定量洗脱苯酚,洗脱率达99%。     

D201树脂吸附钒的静态性能及动力学研究

采用D201树脂对钒溶液进行了静态吸附性能和动力学研究,考察了钒浓度、pH值、温度等因素对静态吸附钒的影响,探讨吸附钒的动力学过程。结果表明,在温度303 K,pH为2.0,五氧化二钒浓度为12 g/L条件下,树脂的饱和吸附容量达306 mg/g;在钒溶液流速为0.02 mL/(min.g)条件下,动态吸附量为270 mg/g。吸附过程遵循Freundlish方程,吸附过程的控制步骤为粒扩散过程,反应级数为拟二级,表观吸附活化能为14.165 kJ/mol。     

大孔树脂对有机废水中苯酚的吸附性能

研究了新型大孔树脂XDA-200对苯酚的吸附性能.实验结果表明,大孔树脂XDA-200对苯酚的最佳吸附pH=6.4,在温度298K时其静态平衡吸附容量为277mg/g树脂.用0.5mol/L NaOH溶液作为解吸剂,一次解吸率可达82.8%.树脂吸附苯酚的过程,符合Freundlich经验式以及Langmuir经验式.树脂吸附苯酚的表观反应速率常数为k298=2.38×10-2/S,表现吸附活化Ea=1.74kJ/mol,测得热力学参数分别为吸附过程热效应AH=5.31kJ/mol,熵变△S=50.8J/mol·K,以及温度288K,298K和308K时的自由能变为:△G288=9.32kJ/mol,AG198=9.83kJ/mol,AG308=-10.34kJ/mol.     

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.     

SQD201树脂对钒的吸附-解吸行为及机理

通过静态吸附-解吸实验研究了SQD201树脂吸附-解吸钒的交换平衡和动力学特性,考察了pH值、温度和溶液浓度对离子交换过程的影响. 结果表明,在298 K、pH=2.0、溶液浓度为0.040 mol/L条件下,SQD201树脂的静态饱和吸附量为573.80 mg/g;钒在SQD201树脂上的吸附是吸热过程,符合Langmuir等温吸附方程. 吸附和解吸过程主要受颗粒扩散控制,吸附过程的表观活化能为20.41 kJ/mol,解吸表观活化能为22.21 J/mol. 吸附机理分析表明,SQD201树脂主要吸附的钒阴离子为H2V10O284-,H2V10O284-与树脂的理论摩尔比为1:4.     

新型交联壳聚糖树脂颗粒对铂的吸附行为

以甲醛为预交联剂、环硫氯丙烷为交联剂,合成了新型交联壳聚糖树脂,用扫描电镜、X射线衍射仪及红外光谱表征了树脂的结构,考察了交联剂用量对铂吸附量的影响,研究了树脂对铂的吸附动力学、等温吸附特性及解吸特性. 结果表明,壳聚糖与交联剂的最佳用量比为壳聚糖:甲醛:环硫氯丙烷=1 g:7 mL:2 mL;树脂吸附铂的动力学符合Boyd液膜扩散方程,其吸附控制过程以液膜扩散为主,表观吸附活化能为14.28 kJ/mol,其等温吸附过程符合Freundlich等温吸附方程;以硫脲(1%)-盐酸(1 mol/L)作为铂的解吸剂,解吸时间为1 h,解吸率达到99.75%.     

低温碱熔-晶化SiO2/Al2O3复合物合成沸石及其对Cd2+的吸附

以SiO2/Al2O3含量较高的粉煤灰(FA)为原料,NaOH为改性剂,采用低温碱熔-水热晶化法合成沸石(ZE)。通过SEM-EDS、XRD、XRF、XPS、FTIR和BET对ZE进行了物相表征,通过静态吸附实验考察了ZE对Cd2+的吸附性能及机理。结果表明：经NaOH改性,FA中Si—O—Si和Si—O—Al 键断裂形成[SiO4]4-和[AlO6]5-单体,ZE比表面积增至21.54m2/g。当ZE投加量为0.1g、Cd2+初始质量浓度为100 mg/L、吸附时间为30min时,平衡吸附量为49.38mg/g,比FA提高57.29%。在pH=4~9时,ZE对Cd2++的去除率在90%以上。在35℃条件下,ZE对Cd2+吸附符合准二级动力学方程,速率常数为0.0586g/(mg·min);ZE对Cd2+的吸附过程符合Langmiur等温模型,1/n为0.4324;热力学实验表明,△G在-20~0 kJ/mol,吸附过程为自发的吸热反应;D-R模型中吸附能均大于16 kJ/mol,ZE对Cd2+吸附过程是物理吸附和化学吸附共同作用的结果。     

硫脲改性壳聚糖对水中Cr(Ⅵ)与Ni~(2+)的吸附性能研究

以壳聚糖和硫脲为原料,经环氧氯丙烷交联,制得硫脲改性壳聚糖颗粒,通过吸附实验考察了pH、吸附时间对Cr(Ⅵ)、Ni2+吸附的影响。结果表明,硫脲壳聚糖颗粒对Ni2+吸附的最佳pH为6,对Cr(Ⅵ)吸附的最佳pH为1,最佳吸附t为2h。利用准一级反应动力学模型和准二级反应动力学模型对实验数据进行拟合,并分别采用Freundlich模型、Langmuir模型对吸附等温线进行拟合。结果表明,吸附符合准二级动力学模型,以化学吸附为主。吸附等温线用Langmuir模型拟合结果最好。在初始质量浓度80mg/L,θ为25℃时,Ni2+,Cr(Ⅵ)的饱和吸附量可达40.98mg/g和33.33mg/g。     

硫脲改性D301树脂的制备及其对AuCl_4~–的吸附性能

使用硫脲对一种苯乙烯系阴离子交换树脂——D301树脂进行改性,先在D301树脂大分子链上接枝聚甲基丙烯酸缩水甘油酯(PGMA),然后通过硫脲与PGMA的环氧基的开环反应制得硫脲改性D301树脂(TD301)。对TD301进行了扫描电子显微镜、傅里叶变换红外光谱、元素分析等表征,研究了硫脲改性条件对TD301吸附性能的影响,并考察了TD301对AuCl_4~–的吸附动力学行为。结果表明,TD301适宜的硫脲改性条件为硫脲用量2 g,反应温度90℃,反应时间8 h;在环境温度25℃,氯金酸溶液pH值为2的情况下,所制得的TD301对AuCl_4~–的吸附量可以达到300.4 mg/g;此外,TD301具有优良的再生与重复使用性能。     

酸性硫脲浸金液中金的富集研究

研究了D072大孔强酸性阳离子交换树脂从硫脲[Tu=CS(NH2)2]浸金液中吸附Au(Tu)2^ 的性能和机理。结果表明：在pH=2.0时,树脂对Au(Tu)2^ 有优良的吸附性能,1gD072大孔强酸性阳离子交换树脂金的交换容量为78．95mg,吸附的硫脲金可用乙醇-硫酸水溶液洗脱,洗脱率可达96．5％。D072树脂对Au(Tu)2^ 的吸附符合Langmuir吸附模型。     

聚酰基硫脲树脂对Cu~(2+)的吸附性能研究

采用对苯二甲酰基二异硫氰酸酯与苯二胺通过界面缩聚反应制备了含有硫脲基团的螯合树脂。通过静态吸附方法,考察了不同的pH值、时间、温度以及Cu2+的初始浓度条件下树脂对Cu2+的吸附性能,初步探讨了树脂对Cu2+的吸附热力学和动力学。结果表明,吸附过程符合Boyd液膜扩散方程,液膜扩散为吸附主要控制步骤;等温吸附可较好符合Langmuir吸附模型,吸附过程为单分子层吸附;吸附容量随温度的升高而增加,吸附为吸热过程。     

CHARACTERISATION OF METALFIX-CHELAMINE AND ITS APPLICATION IN PRECIOUS METAL ADSORPTION

ABSTRACT

The physical and chemical characteristics of the chelating resin Chelamine, which contains a pentamine ligand, are investigated in order to consider its application in the separation of precious metals- Adsorption isotherm experiments for Pt, Pd and Au and kinetic experiments were carried out under batch procedures. The resin presents a high level of adsorption selectivity for Pt(IV), Au(III) and Pd(II) giving a capacity of 2.8 mmol/g, 3.1 mmol/g and 2.0 mmol/g respectively. Acidic solutions, complexing agents, lipophilic anions and ammonia were used for metal elution. NaClO₄ solutions are the most effective eluting agents for Pt(IV) while thiourea is the best stripping agent for both Pd(II) and Au(III). Selective separation of the three metals can be achieved by sequential elution from the resin with NaClO₄ solutions in different HCl concentrations and thiourea 0.5 M.     

Selective adsorption of Au3+ from aqueous solutions using persimmon powder‐formaldehyde resin

A new adsorption resin has been developed by immobilizing persimmon powder with formaldehyde, and its adsorption properties to Au³⁺ were investigated in detail. The resin exhibited outstanding selective adsorption capacity towards Au³⁺ from acidic aqueous solutions (pH 2.0), which the equilibrium adsorption capacity was high up to 3025.20 mg g^?1 at 323 K. The resin exhibited 100% adsorption of Au³⁺ within 8 h, and the experimental data were well fitted with the pseudo‐first/second‐order rate model. The adsorption isotherms could be well described by Freundlich equation. The column studies suggested that the resin was effective for the adsorption of Au³⁺ from aqueous solutions, and the loaded Au³⁺ could be easily desorbed by acidic thiourea solution. The adsorption of Au³⁺ was an endothermic reductive adsorption process. This suggested that the resin can be used as an active biosorbent for the recovery of Au³⁺ from aqueous environment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3937–3946, 2013     

硫脲改性磁性壳聚糖微球对Hg~(2+)的吸附特性

利用悬浮分散以及化学交联技术制备磁性壳聚糖微球,并经硫脲改性(SMCS),用于吸附水溶液中Hg2+。用光学显微图、红外、热重分析等对微球进行了表征;考察了pH值、Hg2+初始浓度、吸附时间以及振荡速率对Hg2+吸附的影响。结果表明,SMCS为球形,粒径50—80μm。SMCS对Hg2+有良好的吸附性能,饱和吸附容量(1.2—6.5 mmol/g)随pH值升高而增加,pH值为5.0时饱和吸附容量约为2.9 mmol/g。等温吸附线可用Freundlich等式拟合。吸附动力学结果表明,振荡速率为150—200 r/min时,为内扩散控制;50—150 r/min时,由外扩散和内扩散同时控制;振荡速率<<50 r/min时,为外扩散控制。吸附动力学可用拟二级模型拟合,初始吸附速率为0.22—1.77 mmol/(g.h),随振荡速率加快而增加。     

Separation and Recovery of Silver(I) Ions from Base Metal Ions by Melamine‐formaldehyde‐thiourea (MFT) Chelating Resin

Abstract

Melamine‐formaldehyde‐thiourea (MFT) chelating resin were prepared using melamine (2,4,6‐triamino‐1,3,5‐triazine), formaldehyde, and thiourea and this resin has been used for separation and recovery of silver(I) ions from copper(II) and zinc(II) base metals and calcium(II) alkaline‐earth metal in aqueous solution. The MFT chelating resin was characterized by elemental analysis and FT‐IR spectra. The effect of pH, adsorption capacity, and equilibrium time by batch method and adsorption, elution, flow rate, column capacity, and recovery by column method were studied. The maximum uptake values of MFT resin were found as 60.05 mg Ag⁺/g by batch method and 11.08 mg Ag⁺/g, 0.052 mg Zn²⁺/g, 0.083 mg Cu²⁺/g and 0.020 mg Ca²⁺/g by column method. It was seen that MFT resin showed higher uptake behavior for silver(I) ions than base and earth metals due to chelation.     

Thiourea modified hyper‐crosslinked polystyrene resin for heavy metal ions removal from aqueous solutions

A hyper‐crosslinked resin chemically modified with thiourea (TM‐HPS) was synthesized, characterized, and evaluated for the removal of heavy metal ions (Pb²⁺, Cd²⁺, and Cu²⁺) from aqueous solutions. The structural characterization results showed that a few thiourea groups were grafted on the surface of the resin with a big BET surface area and a large number of narrow micropores. Various experimental conditions such as pH, contact time, temperature, and initial metal concentration of the three heavy metal ions onto TM‐HPS were investigated systematically. The results indicated that the prepared resin was effective for the removal of the heavy metal ions from aqueous solutions. The isotherm data could be better fitted by Langmuir model, yielding maximum adsorption capacities of 689.65, 432.90, and 290.69 mg/g for Pd²⁺, Cd²⁺, and Cu²⁺, respectively. And the adsorption kinetics of the three metal ions followed the pseudo‐second‐order equation. FTIR and XPS analysis of TM‐HPS before and after adsorption further revealed that the adsorption mechanism could be a synergistic effect between functional groups and metal ions and electrostatic attraction, which may provide a new insight into the design of highly effective adsorbents and their potential technological applications for the removal of heavy metal ions from aqueous solutions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45568.     

Separation and recovery of gold(III) from base metal ions using melamine–formaldehyde–thiourea chelating resin

Melamine–formaldehyde–thiourea (MFT) chelating resin has been prepared. Au³⁺ ions uptake behavior and selectivity of the chelating resin were investigated by both batch and column methods. MFT resin showed higher affinity toward Au³⁺ compared with base metal ions, Cu²⁺ and Zn²⁺. The highest Au³⁺ uptake values were obtained at pH 2 and Au³⁺ adsorption capacity of the resin was calculated as 48 mg Au³⁺/g resin (0.246 mmol Au³⁺/g resin) by batch method. It was concluded that Au³⁺ ions could be selectively concentrated from the solution including Cu²⁺ and Zn²⁺ base metal ions by column method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

腐植酸树脂处理含重金属离子废水可行性探讨

利用泥炭为原料制备腐植酸树脂。在动态条件下,研究了腐植酸树脂对重金属离子Zn2+、Ni2+的吸附效果及吸附条件并探讨了吸附与解吸再生机理:主要吸附形式为离子交换吸附和络合吸附。实验结果表明,在20℃,流速为4mL/min,pH值为5.0～7.0条件下,含Zn2+、Ni2+质量浓度均为70mg/L的废水,经腐植酸树脂处理后,Zn2+、Ni2+去除率可达98%以上,且处理后废水近中性。含Zn2+、Ni2+质量浓度分别为32.5mg/L和29.4mg/L,pH值为5.9的电镀废水,经腐植酸树脂处理后,废水中Zn2+、Ni2+含量显著低于国家排放标准允许值。