Exchange Reaction Characteristics of Anion Exchange Resin for Diclofenac Sodium

Aim To study the exchange reaction characteristics of anion exchange resin for diclofenac sodium. Methods The drug-resin complexes were prepared by a batch method with diclofenac sodium as the model drug and the strong anion exchange resin (201 × 7) as the carrier. The effects of different forms (OH~ - and Cl~ - ) of the strong anion exchange resin, the particle size of the resin, and the reaction temperature on the exchange behavior were described. The exchange kinetic profiles were fitted. The related exc...

A New and Original Method to Produce Ca(OH)<SUB>2</SUB>Nanoparticles by Using an Anion Exchange Resin

Ca(OH)2 nanoparticles in hydro-alcoholic dispersion (nanolime) were successfully employed in Cultural Heritage conservation, thanks to the ability to overcome the limiting aspects of traditional lime treatments. Nanolime were currently produced by chemical precipitation process, at high temperature, with long times of synthesis, and after several purification steps to remove undesired secondary phases. In this paper, an innovative, simple and original method for nanolime production was described. The method was based on an ion exchange process between an anionic resin and a calcium chloride aqueous solution, operating at room temperature. A pure Ca(OH)2 nanoparticles suspension can be rapidly obtained after separating the resin from suspension, and any purification step was necessary. The exhausted resins can be regenerated and reused for a cyclic nanolime production. Structural and morphological features of the produced nanolime were preliminarily characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Moreover, XRD measurements allowed estimating nanoparticles reactivity by following their carbonatation process in air, in relation to different water/alcohol ratios and medium or high relative humidity conditions. The produced Ca(OH)2 nanoparticles appeared hexagonally plated, with dimension less than 100 nm and, compared with those obtained by typical wet precipitation method, they proved to be more reactive.

A New Method for Preparation of Anion Exchange Resins Based on Crosslinked Polvstvrene

This paper presents a new method for preparing anion exchange resins based on crosslinked polystyrene which consists in the acylation of crosslinked polystyrene by FriedelCrafts reaction followed by reductive amination. Aminated resins are quaternized to formcorresponding strong base anion exchange resins. The method avoids the use of carcinogenic chloromethyl methyl ether which is widely used in the preparation of commercial anion exchange resins.

A more precise method to evaluate kinetic leakage of anion exchange resin used in condensate polishing of power plant

Sulfate mass transfer coefficient(MTC) is a sensitive parameter to evaluate the kinetic leakage of anion exchange resin used in condensate polishing system of thermal and nuclear power plant.However,a sufficiently precise determination method has not been well established.In this paper,the final expression of sulfate MTC derived based on plug flow reactor model is the same as Harries' model,which is widely acknowledged in this field.In the determining system we constructed,in-situ calibration of the concentration of sulfate and its cation conductivity was conducted and sulfate MTCs of four typical strongly basic anion exchange resin samples were determined.The systematic error is 8.26% and the calibrated curve used for quantifying sulfate is obtained.The repeatability and reproducibility standard deviation are 0.05×10^(-4) m·s^(-1) and 0.07×10^(-4) m·s^(-1) respectively,which are lower than previous works.By controlling test condition accurately,this study has developed a more precise sulfate MTC determining method.This method provides a basis for further research.

Adsorption characteristics of thorium on silica-based anion exchange resins

To isolate and separate thorium from nitric acid solutions, three silica-based anion exchange resins were synthesized. Batch experiments were carried out to investigate adsorption behavior of thorium in nitric acid solutions. Adsorption at different concentrations of nitric acid and thorium, influence of contact time and coexisting metal ions, and effect of NO3– were investigated in detail. It was found that at high HNO3 concentrations,the resins exhibited higher adsorption capacity and better affinity towards thorium. The adsorption kinetics could be described by the pseudo-second order model equation, while the adsorption isotherms were well correlated by the Langmuir model. The maximum capacity towards thorium species on SiPyR-N4 was evaluated at 27–28 mg/g-resin. The thermodynamic parameters indicated the adsorption was an exothermic reaction. The presence of NO3– was found to promote the retention of the thorium species.

Isolation of Uranium by Anionic Exchange Resins

A separation methodology to isolate natural uranium from its radioactive daughters： Th, Ra, Bi, Pb, Pa and Po, was developed using an only one anion exchange resin and varying concentrations of HC1 solutions. Three types of anion exchange resins were tested and the separation process was followed by gamma and alpha spectrometry. Uranium can be quantitatively isolated from its descendants using Dowex IX8 （20-50 mesh） or Amerlite IRA （100 mesh） resins in three steps： using 4 and 8 mol/L-1 HCI and water to recover uranium. The method is easy, quick, and inexpensive.

THE EFFECT OF IONIC STRENGTH ON THE UPTAKE OF TAURINE ON A STRONG-BASIC ANION EXCHANGE RESIN

Studied the effect of ionic strength on the uptake of taurine on a strong-basic anion exchange resin The batch phase equilibrium experiments of taurine on the anion exchange resin D290 were conducted at different ionic strength, and then the amounts of uptake of taurine on the resin at different pH were determined. The ion exchange mechanisms of taurine on the anion exchange resin at different pH were discussed. Experimental results showed that with increase of the ionic strength of solution, the adsorbed amount of taurine on the resin D290 decreased; Adding small amounts of NaOH or HCl into the system of taurine aqueous solution/D290 anion resin would nfake the amount of taurine taken up on the resin to decrease due to the competition uptakes of hydroxyl ion with taurine or the decrease in the amount of absorbable zwitterions of taurine in the solution and excluding the cations of taurine from the anion resin.

A STUDY ON THE KINETICS OF EXCHANGE REACTIONS OF W（Ⅵ） OR Mo（Ⅵ） WITHIN MACROPOROUS ANION EXCHANGE RESIN（D290） PHASE

The exchange behaviors of WO_4￣(2-) MoO_4￣(2-), H_2 W_(12) O_(40)￣(6-) and Mo8 O_(26)￣(4-) anions within macrOPorous exchange resin (D290) phases have been studied.The values of diffusion constant (B), inner diffusion coefficient (D), retarted time (td) half - exchange-period (t1/2), and activation energy (△E) were found from the kinetic analyses. A new method to separate W(Ⅵ) and Mo (Ⅵ) from each other was also suggested.

离子交换树脂法规模化生产乳源酪蛋白糖巨肽及其对流感病毒的血凝抑制活性

目的:优化规模化生产乳源酪蛋白糖巨肽(CGMP)的工艺条件,并探讨其对流感病毒的血凝抑制能力。方法:以阴离子交换树脂为分离介质,唾液酸含量为产品的活性检测指标,分别从上样体积、上样流量、洗脱液浓度、洗脱液体积和树脂使用周期5个工艺条件,在前期小试和中试的基础上,考察从乳清粉中规模化生产CGMP;同时利用血球凝集抑制试验验证产品CGMP对流感病毒的抑制活性。结果:优化的CGMP产品技术路线为上样体积3BV、上样流量0.8 L/min、洗脱体积1BV、洗脱液浓度0.6 mol/L、树脂适宜使用周期4次。该工艺条件下处理乳清粉溶液体积为108 L(2160 g)、树脂36 L,得到CGMP产品21.183 g,得率为0.981 g/100 g,产品纯度为89.032%,回收率为51.972%,唾液酸含量为21.503 g/100 g,蛋白CGMP产品对流感病毒A(H1N1)和流感病毒B的最低抑制质量浓度分别为1.0000,1.2500 mg/mL。结论:利用优化的技术路线生产获得CGMP产品的纯度和唾液酸含量均优于市售商品CGMP,且对流感病毒有明显的抑制作用。

地质样品铊同位素分析预处理方法优化

铊同位素体系可以示踪天体演化、古环境变化、矿床成因及污染物迁移等地质过程。然而,目前用于铊同位素分析的样品消解和离子交换方法耗时较长,往往需要两周甚至更久;为了提高化学前处理效率,本文采用微波消解法分解样品,以AG1-X8阴离子交换树脂纯化铊,采用多接收器电感耦合等离子体质谱(MC-ICP-MS)测试,仪器的质量歧视用铅同位素标准溶液(NIST SRM981)校正。通过考察消解条件、淋洗曲线和基质效应,结果表明:采用微波消解法,在2mL硝酸-2mL氢氟酸-0.5mL高氯酸的混合酸体系中选用适当的消解程序可以将0.2g土壤标准物质GBW07406消解完全,总耗时不超过2h;利用AG1-X8树脂,上样后,依次以2mL 2mol/L硝酸-1%溴水淋洗6次、2mL超纯水淋洗1次和2mL 0.1mol/L盐酸-6%二氧化硫淋洗5次(收集铊),可有效地纯化铊;常见共存元素的干扰实验结果显示,树脂填充量为2mL时,该淋洗流程所允许上样溶液中含有三价铁和三价铝离子的量分别不应超过2.56mmol和4.90mmol,否则会使铊的回收率降低。将此方法应用于4个地质标准物质中铊同位素比值的测定,ε^(205)TlGSB Tl的精密度(2SD,n=6)均优于0.3;与文献的结果对比显示,标准物质NOD-P-1、GBW07406和GSP-2的ε^(205)Tl差值(ε^(205)Tl_(NIST 997)-ε^(205)Tl_(GSB Tl))均为0.8,NOD-A-1的ε^(205)Tl差值为0.7,说明方法具有较好的准确性;此外,可以估算标准物质GSB 04-1758-2004相对于NIST 997的ε^(205)Tl值应约等于0.8。

液体闪烁法测量退役混合土中^(63)Ni和^(55)Fe

为监测退役核设施中的放射性及其排放,将经过400℃灰化4 h后的样品,用浓盐酸、浓硝酸及氢氟酸的混合酸溶解后加热至干燥,用9 mol/L盐酸溶解,处理后用氢氧化钠沉淀、阴离子交换色谱法及镍特效树脂萃取分离纯化^(63)Ni和^(55)Fe,再用液体闪烁法进行测量,建立了一种反应堆退役混合土样品中^(63)Ni和^(55)Fe的分析方法。结果表明,最终稳定Ni、Fe的回收率分别达98.8%和95.8%,对^(63)Ni的最小探测限和最小可探测活度分别为208(计数)和0.041 Bq,对^(55)Fe的最小探测限和最小可探测活度分别为208(计数)和0.144 Bq,实际样品的^(63)Ni、^(55)Fe活度浓度分别为76.9和30.4 Bq/g。采用标准土壤物质进行回收率模拟实验,达到了95%以上的回收率。分别进行了碱沉淀法、阴离子交换色谱法从多种元素中分离Ni、Fe的实验,其中氢氧化钠沉淀法在pH值处于8.7~11.1时便可以有效使Ni、Fe共沉淀,并去除大部分Re、Sr和全部Cs;阴离子交换色谱法洗脱的镍组分中对Co、Fe、Zn的去污因子均在660以上,铁组分中对Co、Eu、Mn、Ni、Sr、Zn、Zr的去污因子均达2000以上。还分别考察了DMG沉淀法和镍特效树脂法对Ni的纯化效果,DMG沉淀法的Ni回收率为87.14%,镍特效树脂法在镍-干扰元素比例达10∶1以上时,Ni的回收率即接近100%,且干扰元素如Ba、Eu、Fe、Mn、Sr的去污效果达到最佳,因此在使用镍树脂前,宜采用其他方法(如碱沉淀法、离子交换树脂法)进行初步分离。建立的方法操作简单,回收率高,能够满足监测退役核设施中^(63)Ni和^(55)Fe的需求。

Control strategies for disinfection byproducts by ion exchange resin,nanofiltration and their sequential combination

Disinfection byproducts (DBPs) are emerging pollutants in drinking water with high health risks. Precursor reduction before disinfection is an effective strategy to control the formation of DBPs. In this study, three types of anion exchange resins (AERs) and two types of nanofiltration (NF) membranes were tested for their control effects on DBP precursors, DBPs, and total organic halogen (TOX). The results showed that, for AER adsorption, the removal efficiencies of DBP precursors, DBPs, and TOX increased with the increase of resin dose, and the strong basic macroporous anion exchange resin (M500MB) had the highest removal efficiencies. For NF, the highest removal efficiencies were achieved at an operating pressure of 4 bar, and the membrane (NF90) with a smaller molecular weight cut-off, had a better control efficiency. However, AER adsorption was inefficient in removing dissolved organic carbon (DOC);NF was inefficient in removing Br− resulting in insufficient control of Br-DBPs. Accordingly, a sequential approach of AER (M500MB) adsorption followed by NF (NF90) was developed to enhance the control efficiency of DBPs. Compared with single AER adsorption and single NF, the sequential approach further increased the removal efficiencies of DOC by 19.4%–101.9%, coupled with the high Br− removal efficiency of 92%, and thus improved the reduction of cyclic DBPs and TOX by 3.5%–4.9%, and 2.4%–8.4%, respectively;the sequential approach also reduced the cytotoxicity of the water sample by 66.4%.

纳米羟基铁改性阴离子交换树脂用于富营养化水体中磷的吸附净化

为探索一种改良的磷酸盐吸附材料,以优化其在去除富营养化水体中无机磷的应用效果,提出了一种纳米羟基铁(FeOOH)与阴离子交换树脂D-201复合的方法。首先将FeOOH分散于阴离子交换树脂D-201中,得到FeOOH@D-201复合树脂。然后进行批量吸附实验,通过比较FeOOH@D-201与纯D-201对磷酸盐的吸附量来评估其改善程度。并采用准二级动力学模型和Langmuir吸附等温线模型进行拟合,从而分析复合树脂的吸附过程及其机理。结果表明,FeOOH@D-201复合树脂的最大磷酸盐吸附量达到了132.1 mg/g,比纯D-201的吸附量提高了46%,突破了常规阴离子交换树脂在去除无机磷应用中的局限性。模型拟合结果表明,其吸附过程与准二级动力学模型和Langmuir模型较吻合,推断吸附机理主要是静电吸引和配位络合的共同作用。FeOOH@D-201经过5次醋酸脱附-吸附再生循环后,吸附剂去除磷酸盐的能力仍然保持在70.4%以上,证实了复合树脂的良好再生性能。

强碱性阴离子交换树脂的钨钼解吸试验研究

研究了以NaOH+NaNO_(3)为解吸剂、H_(2)O_(2)为强氧化剂,联合从ZGA351大孔强碱性阴离子交换树脂中解吸钨、钼。考察了联合解吸剂组成、NaOH浓度、NaNO_(3)浓度、H_(2)O_(2)浓度及加入量、NaOH+NaNO_(3)/H_(2)O_(2)流速比、解吸次数对钨、钼解吸效果的影响。结果表明:在NaOH浓度1.5 mol/L、NaNO_(3)浓度5%、H_(2)O_(2)加入量为理论量1.2倍、H_(2)O_(2)浓度30%、NaOH+NaNO_(3)/H_(2)O_(2)流速比40条件下进行6次解吸,钨、钼解吸率分别达99.48%、99.38%,树脂的钼穿透吸附量107.10 g/L,与新树脂的钼穿透吸附量107.77 g/L相当,说明ZGA351树脂进行一次解吸—循环吸附后对钼的吸附性能基本保持不变;一次解吸液中钨质量浓度3.82 g/L,钼质量浓度10.71 g/L,钼钨比2.80,调酸后可直接投入工业生产后续工段用于制备钼酸铵产品;30次解吸—吸附循环试验结果表明,树脂使用寿命可满足工业生产成本要求。该法同步完成了解吸液氧化和树脂再生,可简化工艺流程,降低生产成本,为大孔强碱性阴离子交换树脂的解吸工艺提供一种可行的工艺路线。

强碱性阴离子交换树脂从粗钨酸铵溶液中分离钼的研究

研究了采用ZGA351大孔强碱性阴离子交换树脂从粗钨酸铵溶液中吸附分离钼的工艺方法,考察了树脂型号、料液硫含量、料液陈化时间、料液陈化温度、料液pH值、吸附流速、吸附温度对树脂吸附分离钼效果的影响。结果表明:使用100 mL ZGA351树脂进行动态吸附试验,在料液硫含量为理论量1.1倍、料液陈化时间48 h、料液陈化温度40℃、料液pH值10.0、吸附流速15 mL/h、吸附温度40℃的最优条件下,料液钨损失率仅为0.54%,树脂钼穿透容量为107.77 g/L_(湿树脂),相比目前工业生产应用的HBDM-1树脂钼穿透容量提高了3.15倍。另外,重复试验稳定性良好,ZGA351树脂吸附后得到的纯钨酸铵溶液平均钼钨比为0.88×10^(-4),满足工业生产APT产品用纯钨酸铵溶液钼钨比小于2×10^(-4)的需求。综合而言,采用强碱性阴离子交换树脂从粗钨酸铵溶液中分离钼具有钼穿透容量高、钨损失率低、钨钼分离效率高等优势,为工业化应用提供了一种有效技术参考。

树脂吸附苯磺酸类废水工艺探究

选择高水溶性的对甲苯磺酸作为研究对象,利用大孔弱碱性苯乙烯系阴离子交换树脂对其模拟水、实际工业废水进行吸附研究,探讨苯磺酸类废水资源化处理工艺。研究发现,两级D301树脂可将12%对甲苯磺酸钠模拟废水TOC去除72.5%,且用2 BV(BV为树脂装填层体积)6%氢氧化钠溶液作为脱附剂,其脱附率可达到61.2%。针对实际废水,两级D301树脂串联吸附5 BV(0.25 BV/h流速),TOC去除率可达到48.1%,且能实现脱色。一级树脂第2 BV脱附液与第1 BV洗水混合补碱度至6%后,套用脱附二级吸附树脂,可实现两级树脂再生利用,节约工程中树脂脱附运行成本。

Dissolved organic matter removal using magnetic anion exchange resin treatment on biological effluent of textile dyeing wastewater

This study investigated the removal of dissolved organic matter（DOM） from real dyeing bio-treatment effluents（DBEs） with the use of a novel magnetic anion exchange resin（NDMP）.DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight（MW）（〈3 kDa） DOM fractions constituted a major portion（〉50%） of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254absorbance（SUVA254）,and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon（DOC） removal via NDMP treatment was performed by comparing it with that of particle active carbon（PAC）. Results indicated that the removal of DOC from DBEs via NDMP was 60%,whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC,NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants,with selected concentrations of 10% NaCl（m/m）/1%NaOH（m/m）,could improve desorption efficiency.

Selective removal of nitrate by using a novel macroporous acrylic anion exchange resin

An anion exchange resin NDP-5 has been prepared successfully and applied on the selective removal of nitrate from SO_4^（2-）/ NO_3^- binary co-existence system.The composition and morphology of NDP-5 were confirmed by FT-IR and SEM.The NDP-5 resin exhibits the completely different behavior on the adsorption capacity,adsorption kinetic and the effect of the completing anion in the absence or presence of sulfate,compared to D213.And,the resultants of kinetic are well fitted by the pseudo-first-order and pseudo-second-order models.These results are very important to develop novel resins with great features.

Adsorption of Ce(IV) in nitric acid medium by imidazolium anion exchange resin

N-methylimidazolium functionalized anion exchange resin in NO3 form （RNO3） was prepared and used for adsorption of Ce（Ⅳ） in nitric acid medimn. The adsorption amount increased with shaking time increasing and the adsorption equilibrium was obtained within 180 rain. Ce（Ⅳ） was partially reduced to Ce（Ⅲ） and the reduction percent of Ce（Ⅳ） increased with shaking time increasing. But RNO3 was more stable than other resins due to the high resistance to oxidation. A little increase of adsorption amount was found with concentration of HNO3 increasing. However, the reduction percent of Ce（Ⅳ） decreased with the increase of HNO3 concentration. The addition of NaNO3 decreased the adsorption amount of Ce（Ⅳ） on RNO3 due to the competitive anion exchange reaction. Ce（Ⅳ） was adsorbed on RNO3 in the form of Ce（Ⅳ） anion nitrato-complex. RNO3 and Ce（Ⅳ）-loaded RNO3 were characterized by fourier transform infrared （FT-IR） and thermogravimeric analysis （TGA）. Ce（Ⅳ） could be easily separated from RE（Ⅲ） solution by RNO3.

Effect of dissolved organic matter on nitrate-nitrogen removal by anion exchange resin and kinetics studies

The effects of dissolved organic matter （DOM） on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 （A300） and Purolite A 520E （A520E）, would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them. Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Fretmdlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.