Exchange Resin Research Articles

Measurement of 160Tb and 161Tb in nuclear forensics samples

160Tb and 161Tb are important radionuclides to measure when analysing a Nuclear Forensics sample. An analytical method for the measurement of both 160Tb and 161Tb was developed in this study. Terbium was separated and purified using exchange resin and TrisKem LN Resin. The purified fraction containing 160Tb and 161Tb was measured by gamma spectrometry and liquid scintillation counting. The counting efficiencies of 160Tb and 161Tb were determined using the CIEMAT/NIST efficiency tracing method. The LSC count rate ratio, \({{R_{{{}^{160}{\text{Tb}}}} } \mathord{\left/ {\vphantom {{R_{{{}^{160}{\text{Tb}}}} } {R_{{{}^{161}{\text{Tb}}}} }}} \right. \kern-0pt} {R_{{{}^{161}{\text{Tb}}}} }}\), on the reference date was determined by sequential counting and calculated using a custom script based on their half-lives.

Determination of an engineering model for exchange kinetics of strong acid cation resin for the ion exchange of sodium chloride & sodium bicarbonate solutions

This study identified an appropriate engineering model which described the exchange kinetics of sodium ions with a strong acid cation resin. Synthetic resins have potential application for the demineralization of coal seam (CS) water prior to beneficial reuse. However, there is limited data regarding the kinetic behaviour of strong acid cation (SAC) resin for the removal of sodium ions, the most prevalent ions in the water collected from coal seams (produced water) during natural gas extraction. In particular, exchange kinetics need to be understood in relation to estimating how full scale columns of resin may perform. Kinetic analysis revealed that the exchange of sodium ions from both sodium chloride and sodium bicarbonate solutions with SAC resin reached equilibrium within minutes at ambient temperature. Optimal simulation of the kinetic data for both chloride and bicarbonate containing solutions was achieved by application of the Brouers, Weron and Sotolongo (BWS) fractal equation; and this should be used as the basis for development of an engineering model. The model parameters varied depending upon the ratio of resin to liquid employed in the tests, with rates showing substantial enhancement once an excess of resin exchange sites were present. The exchange process was apparently controlled in part by intraparticle diffusion, with three phases inferred for sodium chloride solutions and two for sodium bicarbonate solutions. Other rate limiting phenomena such as film diffusion appeared to play a role under certain conditions.

A simple and rapid method for isotopic analysis of nickel, copper, and zinc in seawater using chelating extraction and anion exchange

Stable isotope ratios of nickel, copper, and zinc are powerful tools for elucidating the biogeochemical cycling of trace metals in the ocean. However, analytical difficulties have impeded isotopic studies of these metals. We present a simple and rapid method for simultaneous analysis of Ni, Cu, and Zn isotope ratios in seawater using NOBIAS Chelate-PA1 resin and anion exchange resin. A NOBIAS Chelate-PA1 resin column was used to quantitatively collect Ni, Cu, and Zn from seawater and thoroughly remove the seawater matrix. Subsequent anion exchange purified and separated the Ni, Cu, and Zn from each other. The blanks used in this method (0.22 ng for Ni, 0.29 ng for Cu, and 0.53 ng for Zn) were sufficiently low to determine the isotope ratios of Ni, Cu, and Zn in surface seawater. Using this method, we analyzed GEOTRACES reference seawater samples (i.e., SAFe D1 and SAFe D2), National Research Council Canada certified materials (i.e., CASS-5 and NASS-6), and seawater samples collected from different depths in the subarctic South Pacific. The results were consistent with previously reported values. This method is expected to accelerate isotopic research and contribute to our understanding of biogeochemical cycling in the ocean.

TASTE MASKING TECHNIQUES: A REVIEW

Taste masking is of critical importance for active ingredients with an undesirable taste, due to the need for increased patient compliance, especially in pediatric and geriatric population. Various techniques for taste masking involve addition of flavours, sweeteners and amino acids, use of effervescent agents, prodrug formation, salt preparation, adsorption, formation of complex with ion- exchange resins, inclusion complexes and molecular complexes, microencapsulation, granulation, viscosity modifiers, multiple emulsion, liposomes and solid dispersion systems. In pharmaceutical industry, taste masking involves the development of a system that prevents the active substance from interacting with taste buds, thereby reducing the negative sensory response. This article reviews the different technologies which are used for masking the bitter taste and methods for evaluation of taste masking efficacy.

Operating experience and developments of G-REX and AuRIX®100 resin exchange technology

Operating experience and developments of G-REX and AuRIX®100 resin exchange technology

Ionic Behavior Assessment of Surface‐Active Compounds from Corn Steep Liquor by Exchange Resins

AbstractDepending on their ionic nature, biosurfactants can be classified as nonionic, anionic, cationic, or amphoteric. The ionic behavior of biosurfactants is an important characteristic that dictates their use in industrial applications. In this work, a biosurfactant extract obtained from corn steep liquor was subjected to anionic or cationic resins, in order to study the ionic behavior under different operational conditions using response surface methodology. The independent variables included in the study are the dilution of biosurfactant solution, the amount of cationic or anionic resin, and the extraction time, whereas the dependent variables studied consisted of the surface tension of biosurfactant aqueous solution, after contacting with anionic or cationic resin. The results showed that biosurfactant extracted from corn steep liquor is amphoteric, since both resins were able to entrap this biosurfactant, making it particularly suited for use in personal care preparations for sensitive skin.

A New Method for Extraction and Heavy Metals Removal of Abalone Visceral Polysaccharide

This study developed a new method to extract abalone visceral polysaccharide (AVP) and remove its heavy metals (except for mercury) by combining enzymatic hydrolysis, plate frame filtration, alcohol precipitation, high activated clay absorption with cation exchange resin and anion exchange resin. Alcohol precipitation, dialysis, activated carbon adsorption and high activated clay adsorption were used to remove mercury in AVP, respectively. Results indicated that these technologies are credible that both AVP with higher purity and heavy metals in AVP met the limit of standard. High activated clay could remove mercury more efficiently and increase the yield of AVP compared with other methods. The methods of inductively coupled plasma mass spectrometry and atomic absorption spectrophotometer were established to detect cadmium, lead, arsenic, chromium, nickel and mercury of AVP, respectively. Results indicated that the established methods were credible and effective by analyzing uncertainty evaluation, recovery rates and precision. Practical Applications AVP with higher purity and yield, content of heavy metals in AVP also met the limit of standard by the technologies of extraction and heavy metals removal of AVP. It was credible and effective for using ICP-MS and AAS to detect cadmium, lead, arsenic, chromium, nickel and mercury of AVP, respectively. The application of these methods can help food industry to develop AVP into healthcare products and researchers in the production of abalone visceral polysaccharide.

Assessment of N Mineralization and N Leaching in Soil Using a New in situ Incubation Method

ABSTRACTField incubations have been pointed out as the more realistic method to provide estimates of nitrogen (N) mineralization. The aim of this study is to evaluate the quality of the results obtained in a field incubation using an open reactor to estimate net N mineralization and N leaching. The incubation experiment was initiated with 24 reactors. At each date, the reactors were destructed and mineral N in the soil and adsorbed on the exchange resins was determined. Net N mineralization and N leaching were estimated as 23.3 and 18.0 mg/kg, respectively. The results revealed an acceptable repeatability, with coefficient of variation (CV) of 9.0%, a significant adjustment (r2 = 0.991), and a low root mean square error (Syx = 4.2) for the regression model used. The use of this type of reactor may be considered as a reliable alternative to assess N mineralization kinetics from native organic matter and probably for organic residues applied to soils in field studies.

Improved lactic acid productivity by simultaneous recovery during fermentation using resin exchanger

Lactic acid is a versatile organic acid that can be used in various applications. One of the promising applications of lactic acid is in bioplastic industry. Lactic acid is used as the monomer building block in polylactic acid synthesis. Unlike the existing applications in food and pharmaceutical industries in which lactic acid is used as the additive, it becomes the major raw material in polylactic acid production. This, therefore, raises the demand of lactic acid and eventually increases the market price. In order to expedite the bioplastic industry, cost competitiveness to the existing plastic is a big concern. The cost effectiveness and process robustness are the key success factors in bioplastic industry. Currently, lactic acid is produced via bacterial fermentation using the lime-based process. After fermentation, lactic acid was recovered from the fermentation broth by various techniques including solvent extraction, reactive distillation, ion exchanger, and electrodialysis. To achieve low production cost, not only high fermentation rate is necessary, effective recovery process is also required. In this study, we attempted simultaneous recovery of lactic acid coupled with fermentation to drive the productivity and long-term operation in continuous culture. Anion exchange resin, Amberlite IRA-400, was selected for recovering lactic acid from the bacterial culture. The preliminary results in batch adsorption showed that among other resins studied, Amberlite IRA-400 provided the best separation efficiency. Further study on fixed bed adsorption and simultaneous fermentation and lactic acid recovery using this resin were conducted and the results will be discussed in this presentation.

Reactive ion exchange processes of nonferrous metal leaching and dispersion material synthesis

Two combining reactive ion exchange processes with the application of cation exchange resins have been considered: the cation resin exchange leaching of metal ions from mineral and technogenic raw materials using cation exchange resin in the form of hydrogen and the anion resin exchange precipitation of metal ions in the insoluble compound form with the application of anion exchange resin in hydroxide and salt forms. The applications of methods are illustrated by examples for selective leaching of metals from its oxides, hydroxides, and silicates, as well as by the synthesis of hydroxides, carbonates, oxalates of nickel, cobalt, and other metals.

High D(−) lactic acid levels production by Sporolactobacillus nakayamae and an efficient purification

This study is the first to report the efficient production of D(−) lactic acid by a strain of Sporolactobacillus nakayamae utilizing inexpensive peanut flour as a nitrogen source and commercial sucrose as a carbon source. A D(−) lactic acid concentration of 112.93 g/L was obtained by fermentation using 110.00 g/L of commercial sucrose, 150.40 g/L of peanut flour, and 0.16 ml/L of Tween 80. The optimal medium composition was determined using experimental design such as a Plackett-Burman, fractional factorial designs, and response surface methodology. The purification and recovery of D(−) lactic acid from the fermentation medium were performed using two purification techniques (filtration with activated carbon, followed by celite and cation resin exchange). This approach showed a high efficiency in protein and sugar removal as well in D(−) lactic acid recovery from the fermentation medium. Thus, the results indicate that S. nakayamae is a promising new D(−) lactic acid producer.

Chromium Removal From Strong Base Anion Exchange Waste Brines

Regeneration of strong base anion (SBA) exchange resin produces concentrated and hazardous brine. In this research, one alternative regenerant and two brine treatment options were investigated to reduce the hazardous characteristics of the brine. These options included replacing sodium chloride with sodium bicarbonate as the regenerant, using ferrous sulfate (FeSO4) to reduce/coagulate hexavalent chromium (CrVI) in the brine, and applying weak base anion (WBA) exchange resin and chemical reductive media (CRM) to adsorb/reduce CrVI. It was found that bicarbonate was as effective as chloride in regenerating chromium‐saturated resins, and the affinity of the bicarbonate‐form resin for chromium was similar to that of the chloride‐form resin. It was observed that FeSO4 applied at doses close to the stoichiometric ratio achieved almost complete removal of total chromium from the SBA brine. In column tests, two CRM exhibited more than 20 times greater removal capacity for total chromium than did the WBA exchange resins.

Complement receptor activity of recombinant porcine CR1-like protein expressed in a eukaryotic system.

Primate complement receptor type 1 (CR1) protein, a single-chain transmembrane glycoprotein, plays an important role in immune adherence and clearing complement-opsonized immune complexes. Here, the mRNA of the porcine primate-like complement receptor (CR1-like) gene was analyzed, and two domain sequences with potential functions were cloned into the pwPICZalpha vector for expression in Pichia pastoris. The recombinant proteins were purified with both Protein Pure Ni-NTA resin and strong anion exchange resin. The activities of the purified recombinant proteins were evaluated by SDS-PAGE, western blotting, and complement receptor assays. The results indicated that two domains of the CR1-like protein, CCP36 and CCP811 with molecular weights of 29.8kDa and 30kDa, respectively, were successfully expressed in P. pastoris. These two recombinant proteins possess some of the functions of the primate CR1 protein. Using these two proteins coupled with an antibody blocking technique, we also showed that CR1-like is expressed on natural porcine erythrocytes.

An optimization-driven novel operation of simulated moving bed chromatographic separation

Improvements of conventional SMB operation, such as in Varicol, Modicon, and Powerfeed, have enhanced SMB performance in the past decade. In this work, we propose a novel strategy that incorporates changing internal flow rates and switching periods periodically to enhance flexibility of operation and simultaneously enhance the purity of key product. This mode of operation, called as a dual switching strategy, has been investigated from a modelling perspective with simulation studies to validate the findings. The study incorporates detailed multiobjective optimization problem formulation focusing on performance metrics such as extract purity, recovery and throughput. Unlike the classical SMB processes, dual switching offers a wider scope with its larger degrees of freedom to mutually enhance purity and concentration of key product without the need for SMB configuration modifications. The results reveal a possible fractionating effect on the product side leading to two different purity fractions. Superior performance over the conventional operation has been validated by comparison with classical operation on an SMBC process for separation of glucose and fructose using Ca++ exchange resin.

Treatment of arsenic wastewater by ion-exchange resin

利用选择性复合树脂处理含砷废水，使出水水质达到国家《地表水环境质量标准》（GB 38382002），同时从选择性复合树脂和阳离子柱上交换下来的离子可以生成H₂O和中性盐类，无二次污染.研究采用201×7苯乙烯系强碱凝胶型树脂（Ⅰ）和D301大孔弱碱阴离子交换树脂（Ⅱ）作为比选树脂，通过小试试验选择具有较高交换容量的201×7苯乙烯系强碱凝胶型树脂用于放大规模的现场中试.实验所用选择性复合树脂制作成本及整个中试系统价格低廉，适合大规模工厂应用.;The selective composite resins were used to treat spring water containing arsenic, and the arsenic concentration in the effluent reached the Environmental Quality Standards for Surface Water(GB 3838-2002). Ions exchanged from the selective composite resin and cation exchange column have yielded H₂O and neutral salt, and this method has no secondary pollution. 201×7 gel type styrene of strong akali resin (Ⅰ) and D301 macroporous have weakened the akali anionic exchange resin (Ⅱ), when compared to choose the suitable resin for arsenic removal in this study. The 201×7 resins with higher exchange capability and lower cost were applied to the pilot scale experiments on site and they were suitable to large-scale applications.

Adsorptive Cation Exchanger Mixed Matrix Membrane Chromatography for the Isolation of Lysozyme from Chicken Egg White

Membrane chromatography, which uses an adsorptive membrane, is an alternative technology that overcomes the limitations of packed-bed column chromatography. Mixed matrix membrane (MMM) preparation is a simple method by which adsorptive membranes can be prepared. In the current study, several potential low-cost cation exchange (CEX) resins were screened for their ability to bind lysozyme (LYS) at various pH values prior to the preparation of CEX MMMs. The best binding was shown by Lewatit CNP105 at pH 7. A subsequently prepared Lewatit CNP105—CEX MMM followed the Langmuir adsorption isotherm, with a maximum binding capacity of 223 mg LYS/g membrane. In batch binding from a chicken egg white (CEW) solution at pH 7, both positively charged (LYS, pI 10.7) and negatively charged (conalbumin (CNL), pI 6.1; and ovalbumin (OVL), pI 4.5) proteins were bound onto the MMM. However, CNL and OVL were only loosely bound and were washed out during the washing step. Almost pure LYS was recovered during the elution step, as shown by SDS–PAGE gel analysis.

Sodium Dihydrogen Phosphate Starting From Sodium Chloride and Orthophosphoric Acid Via Cation Resin Exchange

GRAPHICAL ABSTRACT

Removal of Cr(VI) from wastewater by FeOOH supported on Amberlite IR120 resin

Resin-supported FeOOH (R-FeOOH) was synthesized by the chemical reaction of Fe3+-exchange resin with H2O2. R-FeOOH was characterized with scanning electron microscopy and X-ray powder diffraction. The optimum R-FeOOH was synthesized in the presence of 0.5 mol/L Fe3+ and 0.09 mol/L H2O2. Then, R-FeOOH was employed to remove Cr(VI) from aqueous solutions under different conditions. The results indicated that the removal efficiencies of Cr(VI) were all over 98% for initial Cr(VI) concentration of 20.0 mg/L at initial pH of 2.0, 3.0, 5.0, and 7.0, with R-FeOOH dose of 15.0 g/L after reaction for 120 min. The Cr(VI) removal efficiency can attain 100% at pH 3.0 after reaction for 90 min. Besides, a test on the reuse of the R-FeOOH was conducted. The removal of Cr(VI) by R-FeOOH was through adsorption, ion exchange, and reduction. R-FeOOH can be an effective agent for Cr(VI) removal from wastewater.

Optimal strategies for transitions in simulated moving bed chromatography

Simulated moving bed chromatography (SMBC) has emerged as a significant separation technology in the process industry. SMB operating parameters are chosen to satisfy various performance objectives such as maximization of purity or productivity and the choice of the objective is generally guided by process economics. From an industrial perspective, the SMB must be operated flexibly, so that the same unit can be operated to satisfy different objectives. Transiting from one objective to another entails large transition periods, resulting in an economic loss. We propose use of optimal transitions as an approach to minimizing transition time, reducing use of feed and desorbent during transition as well as reduction in off-specification product relative to a non-optimal, step change approach. Optimal transitions can also be used in recovering from feed upset scenarios. The above methods are demonstrated using simulations on a benchmark SMBC process for separation of glucose and fructose using Ca++ exchange resin.

Modeling of esterification in a batch reactor coupled with pervaporation for production of ethyl acetate catalyzed by ion- exchange resins

In the chemical industry, process intensification is needed to meet important goals such as sustainable and eco-friendly processes. For esterification reaction the “produce more with less pollution” objective can be achieved by coupling reaction and separation in a so called integrated process. In this work a model for describing the esterification reaction of ethyl acetate in pervaporation membrane reactor using amberlyst 15 as a heterogeneous catalyst and polydimethylsiloxane (PDMS) membrane, was developed. This earth-friendly method with low pollution and high yield is an alternative to hazardous methods because using pervaporation membrane reactor reduces both waste and energy consumption. The validity of the model was tested by comparing the calculated results with experimental data reported in the literature. It was shown rate of conversion increased by removing ethyl acetate from the reaction mixture. A parametric study was carried out to evaluate the effects of operating conditions on the performance of the pervaporation membrane reactor. Conversion increased by increasing the temperature, molar ratios of reactants and catalyst concentration.