Response surface methodology for optimizing adsorption performance of gel-type weak acid resin for Eu(Ⅲ)

The conditions relating to enhanced adsorption procedure of earth element europium（Eu） onto gel-type weak acid resin（110-H） in aqueous solution were optimized by means of the response surface methodology（RSM）, which proved that 110-H owned satisfactory adsorption capacity（346.85 mg/g） in optimum conditions, belonging to one of the high adsorption capacity materials. Then, the adsorption and desorption behaviors were investigated by batch studies. The adsorption performance showed high agreement with the Lagergren-first-order model and Langmuir isotherm with thermodynamic adsorption parameters of ΔH= 36.1 k J/mol and ΔS=200 J/（mol·K）. Desorption study revealed that 110-H could be effectively eluted by a low concentration of HCl solution（0.1 mol/L） to regenerate and reuse. Finally, the 110-H and Eu（III） loaded 110-H were characterized by IR spectroscopy and scanning electron microscope（SEM） to analyze the mechanism of adsorption, which proved to be chemisorbed.

Adsorption behavior of gel-type weak acid resin (110-H) for Pb^(2+)

The adsorption properties of a novel gel-type weak acid resin (110-H) for Pb2+ were investigated using chemical methods and IR spectrometry.The optimal adsorption condition of 110-H for Pb2+ is at pH=6.49 in HAc-NaAc medium and the statically saturated adsorption capacity is 485 mg/g at 298 K.Pb2+ adsorbed on 110-H resin can be eluted with 0.025 mol/L HCl quantificationally.The adsorption rate constants determined under the temperatures of 288,298,308 and 318 K are 2.46×10-5,3.82×10-5,4.46×10-5 and 5.71×10-5 s-1,respectively.The apparent activation energy,Ea,is 18.1 kJ/mol and the thermodynamic parameters of adsorption,ΔH=20.9 kJ/mol,ΔS=161 J/(mol.K) and ΔG298 K =-48.0 kJ/mol,respectively.The adsorption behavior of 110-H resin for Pb2+ accords with the Langmuir isotherm.Infrared spectra show that the oxygen atoms of the functional group of resin coordinate with Pb2+ to form the coordination bands.

Adsorption behavior of ytterbium (Ⅲ) on gel-type weak acid resin

The adsorption and desorption behaviors of Yb（Ⅲ） on gel-type weak acid resin （110） were investigated. The influence of operational conditions such as contact time,initial concentration of Yb（Ⅲ）,initial pH of solution and temperature on the adsorption of Yb（Ⅲ） were also examined. The results showed that the optimal adsorption condition of 110 resin for Yb（Ⅲ） was achieved at pH=5.5 in HAc-NaAc medium. The maximum uptake capacity of Yb（Ⅲ） was 265.8 mg/g at 298 K. Yb（Ⅲ） could be eluted by using 3.0 mol/L HCl solution and the 110 resin could be regenerated and reused. The adsorption of Yb（Ⅲ） followed the Langmuir isotherm,and the correlation coefficients were evaluated. Various thermodynamic parameters such as standard enthalpy change （△H）,standard entropy change （△S） and standard free energy change （△G） were evaluated. The adsorption of Yb（III） on the 110 resin was found to be endothermic in nature. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristics parameters of the column useful for process design. And the resin sample both before and after adsorption was described by IR spectroscopy.

Adsorption of Pb^(2+) on macroporous weak acid adsorbent resin from aqueous solutions: Batch and column studies

The adsorption properties of a novel macroporous weak acid resin （D152） for Pb^2＋ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb^2＋ is at pH 6.00 in HAc-NaAc medium. The statically saturated adsorption capacity is 527 mg/g at 298 K. Pb^2＋ adsorbed on D152 resin can be eluted with 0.05 mol/L HCI quantitatively. The adsorption rate constants determined under various temperatures are k288 n=2.22×10-5 s^-1, k298 K=2.51 × 10^-5 s^-1, and k308 K= 2.95 × 10^-5 s^-1, respectively. The apparent activation energy, Ea is 10.5 kJ/mol, and the adsorption parameters of thermodynamics are ΔH^Θ=13.3 kJ/mol, ΔS^Θ=119 J/（mol·K）, and ΔG^Θ298 K =-22.2 kJ/mol, respectively. The adsorption behavior of D152 resin for Pb^2＋ follows Langmuir model.

Adsorption behavior and mechanism of D113 resin for lanthanum

The sorption properties of macroporous weak acid resin （D113） for La^3＋ ion were studied by chemical analysis and IR spectra. Experimental results indicate that the D113 resin has a good adsorption ability for La^3＋ at pH = 6.0 in the HAc-NaAc medium. The statically saturated adsorption capacity is 273.3 mg/g. Separation coefficients of βLa^3＋/Ce^3＋, βLa^3＋/Gd^3＋, βLa^3＋/Er^3＋, and βLa^3＋/Y^3＋ are 2.29, 3.64, 4.27, and 0.627, respectively. The apparent activation energy of adsorption, Ea is 18.4 kJ/mol, the thermodynamics parameters AH, AS, and AG of sorption are 4.53 kJ/mol, 61.8 J/（mol·K）, -13.9 kJ/mol, respectively. The adsorption behavior of D113 for La^3＋ obeys the Freundlich isotherm. La^3＋adsorbed on resin can be eluted by 2.0 mol/L HCl quantitatively.

Sorption Behaviour and Mechanism of Lanthanum (Ⅲ) on HD-2 Resin

La(Ⅲ) was quantitatively adsorbed by macroporous weak acid resin (HD-2) in the medium of pH=6.16. The statically saturated sorption capacity is 231 mg·g -1(resin). 3.0 mol·L -1 HCl can be used as an eluant. The elution percentage is 100%. The sorption rate constant is k_ 298=3.04×10 -5 s -1. The apparent sorption activation energy of HD-2 for La(Ⅲ) is 31.2 kJ·mol -1. The sorption behavior of HD-2 for La(Ⅲ) obeys the Freundlich isotherm. The adsorption parameters of thermodynamic are ΔH=9.56 kJ·mol -1, ΔS=35.7 J·mol -1·K -1, ΔG=-1.08 kJ·mol -1, respectively.

DK-13和DK-3两种大孔弱酸阳离子树脂提取西索米星的吸附热力学和动力学研究

目的采用静态吸附实验考察了DK-13、DK-3两种大孔弱酸阳离子树脂对西索米星的吸附热力学和动力学行为。方法用刚果红分光光度法测定不同温度和不同初始浓度下的吸附等温线和吸附动力学、热力学曲线等。结果两种树脂对西索米星的吸附过程符合Langmuir吸附等温方程(R2>0.998)和拟二级动力学模型(R2>0.995);热力学参数计算结果显示,吉布斯自由能变ΔG、焓变ΔH、熵变ΔS均大于零,说明其吸附过程为非自发吸热的熵增过程。同时,研究还发现DK-13树脂交换带长度为DK-3的5.2倍,表明DK-13树脂适用于固定床而DK-3树脂用于连续离子交换床更有利。结论本研究结果为大孔弱酸阳离子树脂吸附提取西索米星工艺的工业化应用提供了理论指导。

Adsorption behavior of benzenesulfonic acid by novel weakly basic anion exchange resins

Two novel weakly basic anion exchange resins（SZ-1 and SZ-2） were prepared via the reaction of macroporous chloromethylated polystyrene-divinylbenzene（Cl-PS-DVB） beads with dicyclohexylamine and piperidine, respectively. The physicochemical structures of the resulting resins were characterized using Fourier Transform Infrared Spectroscopy and pore size distribution analysis. The adsorption behavior of SZ-1 and SZ-2 for benzenesulfonic acid（BA） was evaluated, and the common commercial weakly basic anion exchanger D301 was also employed for comparison purpose. Adsorption isotherms and influence of solution p H, temperature and coexisting competitive inorganic salts（Na2SO4and Na Cl） on adsorption behavior were investigated and the optimum desorption agent was obtained.Adsorption isotherms of BA were found to be well represented by the Langmuir model.Thermodynamic parameters involving ΔH, ΔG and ΔS were also calculated and the results indicate that adsorption is an exothermic and spontaneous process. Enhanced selectivity of BA sorption over sulfate on the two novel resins was observed by comparison with the commercial anion exchanger D301. The fact that the tested resins loaded with BA can be efficiently regenerated by Na Cl solution indicates the reversible sorption process. From a mechanistic viewpoint, this observation clearly suggests that electrostatic interaction is the predominant adsorption mechanism. Furthermore, results of column tests show that SZ-1possesses a better adsorption property than D301, which reinforces the feasibility of SZ-1for potential industrial application.

离子交换法提取发酵液中乳酸的工艺研究

选用弱阴离子树脂D301G和D311从发酵液中提取乳酸,研究过程中对时间、温度、发酵液浓度、转速、pH值、流速和树脂填充量等影响因素加以系统考察。通过单级工艺研究确定最佳操作条件为:时间3h、发酵液浓度86.0g/L、pH3,此条件下的交换容量为237mg/g。另外对特定树脂吸附乳酸的动力学和热力学也进行了研究,得到了D301G的等温吸附曲线,符合Freundish吸附等温方程,方程为Qc=KC1/n,其吸附过程的动力学方程为Qt=Q0+aet/b。

螯合树脂D751和弱酸性树脂112×1的碱土、稀土和过渡金属树脂盐的研究

测定了在加有乙酸钠的弱碱性溶液中,碱土、稀土和过渡金属离子在具有亚胺二乙酸功能基的D751和具有羧酸功能基的112×1树脂上吸附达到饱和时,树脂中功能基和金属离子的摩尔数之比,测定了各种纯金属离子式树脂的红外光谱,并由此讨论了上述三种金属离子与两种树脂上功能基的成键性质。

D113弱酸性树脂对铟(Ⅲ)的吸附性能

研究了D113弱酸性树脂在NaAc-HAc缓冲体系中对铟(III)的吸附性能及机理。对影响树脂吸附容量的不同因素,如溶液的pH、吸附时间和温度进行了研究。结果表明:D113弱酸性树脂对铟(III)的吸附在pH=5.00的NaAc-HAc缓冲体系中最佳,每克树脂在298 K下的静态饱和吸附容量为185 mg;在不同温度下,树脂吸附铟(III)的表观吸附速率常数分别为k288K=2.72×10.5 s.1,k298K=3.69×10.5 s.1,k308K=4.48×10.5 s.1,表观吸附活化能Ea=18.4 kJ.mol.1;测得热力学参数分别为.H=3.27 kJ.mol.1,.S=68.3 J.(mol.K).1,.G298K=.17.1 kJ.mol.1。与Freundlich等温曲线相比,吸附更加符合Langmuir等温曲线。用0.5 mol.L.1 HCl进行解吸时,解吸率为100%。此外,用红外光谱方法探讨了吸附机理,结果显示:D113树脂功能基COOH中的H与In(III)发生了离子交换;同时,C=O中的O与In(III)形成了配位键。

强碱弱酸两性树脂的合成、结构性能及吸附性能

以苯乙烯和丙烯酸为单体、二乙烯苯为交联剂 ,在致孔剂环己烷和甲苯存在条件下 ,用悬浮聚合法制得了一系列的大孔间聚物 .通过测定树脂孔结构性能和对柠檬酸的等温吸附性能 ,讨论了不同交联剂及致孔剂用量和配比对间聚物结构的影响 。

弱酸性交换树脂处理含铅废水动态吸附行为研究

采用110弱酸性树脂对废铅酸蓄电池在回收过程中产生的破碎分选废水(浊环水)进行了脱铅深度处理。通过柱动态试验,考察了树脂形态、温度、流速等因素对吸附及脱附的影响。结果表明,优化的吸附条件为:树脂Na型、流速20 BV/h、温度30℃,吸附过程符合Yoon-Nelson模型,流出液前2000BV Pb2+的质量浓度小于1mg/L,树脂饱和吸附量为592.6mg/g;优化的脱附条件:脱附剂HNO3(浓度1.5mol/L)、流速10BV/h、温度20～30℃,脱附液中Pb2+的质量浓度达45.72g/L。

含醚键的弱酸型酚醛树脂的合成及其对金属离子的吸附性能

以浓硫酸为缩合催化剂，苯氧乙酸和甲醛为原料，合成了一种分子内含醚键的新型弱酸性酚醛树脂，研究了该树脂对几种重金属离子的吸附性能，并对吸附时间、温度、溶液pH值及浓度等因素对吸附性能的影响作了系统考察。结果表明，该树脂对Cu2+，Ni2+，Pb2+，Zn2+的静态吸附容量均可达到2．0mmol／g以上；其中吸附率可分别达到90％，91％，91．3％和100％。吸附了金属离子的树脂可经5％～10％盐酸再生并回收金属离子。文中还对树脂的吸附机理作了初步探讨。

弱酸性条件起始合成MUF树脂工艺研究

为了开发一种新的在"弱酸—弱碱—弱酸—弱碱"条件下合成三聚氰胺-尿素-甲醛树脂(MUF)的工艺,对弱酸性条件下起始合成MUF工艺进行研究.探讨了在不同酸性阶段加入的三聚氰胺对脲醛树脂性能的影响,找出最佳的三聚氰胺改性脲醛树脂的合成工艺.在最佳工艺基础上,评价三聚氰胺用量对MUF树脂性能的影响以及对胶合板性能的影响,并对MUF树脂和普通脲醛树脂进行红外分析.结果证明:三聚氰胺在甲醛与尿素一次缩聚之后加入,对脲醛树脂改性效果最好,其胶合板湿剪切强度与甲醛释放量之间达到较好平衡,胶合板甲醛释放量为0.63mg/L,湿剪切强度为1.03MPa.红外谱图分析表明:三聚氰胺分子以亚甲基与脲醛树脂分子链相连并有可能嵌入脲醛树脂分子链中,形成一定数量的醚键,使三聚氰胺在脲醛树脂中真正起到骨架作用.

S-腺苷-L-蛋氨酸在弱酸树脂上的离子交换平衡

结合Donnan膜平衡理论与树脂的弱电解质性质,在假设S-腺苷-L-蛋氨酸(SAM)分子带一价正电荷的基础上,建立了SAM在D113弱酸树脂上的离子交换平衡模型.实验测定了初始pH值为2.30、5.01、7.13及8.13时的等温离子交换平衡数据,通过实验数据拟合得到了两个模型参数.实验数据拟合结果表明,在初始pH值为5～8时,两参数的模型较好地描述了离子交换平衡.

适合海上油田配聚水软化的弱酸型树脂性能研究

针对渤海绥中36-1油田配聚水硬度高、黏度损失大的问题,通过静态与动态试验研究了弱酸薄壳型离子交换树脂BHS-1的软化性能。结果表明:该树脂耐温可达75℃,最高耐矿化度可达20 000 mg/L,耐铁可以达到5mg/L。在油藏条件下,树脂的泄漏点能保证在7 h以上,具有良好的除钙能力;BHS-1树脂的耐铁性试验结果表明:随着原水中铁离子浓度的增大,泄漏点将会提前。在铁离子达到5 mg/L时,树脂在5 h内产水基本不发生泄漏,且容易再生,不会产生铁污染问题。

固定床吸附法提取发酵液中乳酸的工艺条件优化

预处理后的乳酸发酵液,经过5种树脂对吸附及解吸性能的筛选,确定选用弱阴离子树脂D301G从发酵液中提取乳酸.在正交试验优化基础上,得到该树脂单级工艺最佳操作条件为:时间3h、发酵液浓度86.0g/L、pH值为3,此时交换容量为237mg/g.又测定了流速和高径比对固定床吸附操作的影响,最终确定流速为1mL/min,高径比为10.8:1是最优固定床吸附工艺条件,并绘制该条件下的穿透曲线,此时穿透时间为60min,交换容量为193mg/g.

弱酸性树脂吸附低浓度游离碱行为的研究

利用电导实验技术 ,跟踪观察弱酸性树脂吸附低浓度游离碱的行为 ,研究温度对吸附的影响 ,测定吸附活化能 ( Ea)和吸附剂 -吸附质相互作用能 ( U)。实验结果表明 ,温度升高 ,吸附剂 -吸附质相互作用能增加 ,表观吸附速率常数 ( k)增大 ,而且 U与 T存在良好的线性相关 ( r=0 .995 1 )

火电厂循环水弱酸树脂处理工艺的研究与应用

为了确定弱酸树脂处理工艺的控制参数,在实验室对D113弱酸树脂的运行基本规律、工作交换容量、出水特性、树脂层高、流速、再生剂比耗等因素进行了试验研究;列举了弱酸处理工艺的成功应用案例;指出了弱酸处理工艺在火电厂循环水实现高浓缩倍数运行的技术优势。