Ion Exchange Resin Research Articles

Feasibility study for industrial conditioning of spent ion-exchange resins by impregnation with a polymer binder

Feasibility study for industrial conditioning of spent ion-exchange resins by impregnation with a polymer binder

Degradation of the AMP/PZ-based solvent CESAR1 and effects of solvent management in two longtime pilot plant tests

Two 24/7 longtime testing campaigns at the CO2 capture pilot plant at Niederaussem with an accumulated testing time of more than 40,000 h with the CESAR1 solvent, an aqueous solution of 26.7 wt% 2-amino-2-methylpropan-1-ol (AMP) and 12.9 wt% piperazine (PZ), provide a unique data base for the development of solvent management technologies and the evaluation of hypotheses on amine degradation. In the first campaign with a testing time of 34,000 h without replacement of the solvent inventory, three solvent management strategies with different effect mechanisms were investigated: adsorptive removal of trace elements from the solvent by two kinds of active carbon, removal of ionic contaminants by ion exchange using cation and anion exchange resins, and removal of NO2 from the flue gas by treatment with a thiosulfate/sulfite solution. After replacement of the solvent inventory the second campaign was conducted, in which none of the solvent management technologies mentioned have been applied for 10,000 h. The results of the two campaigns allow a direct comparison of the solvent degradation behavior. It is shown that active carbon does not significantly affect the accumulation rate of degradation products in CESAR1, and that an inappropriate kind of active carbon can cause foaming. Anionic degradation products, metal complexes, trace components and cationic contaminants can be effectively removed from the aged solvent by ion exchange. However, after their removal, accelerated formation of oxidative degradation products by a factor of up to 3 higher than before the anion exchange was observed. Removal of NO2 from the flue gas did not affect the NH3 emissions from the CO2 absorber, but it led to the highest observed increase rate of the accumulation of acidic degradation products for aged CESAR1. The results show that exaggerated efforts for solvent management are contra-productive and that a reassessment of the effect mechanisms of solvent management technologies is necessary.

Effect of feeding amount on tail gas and waste salt obtained from molten salt oxidation process of cation exchange resins

ABSTRACT The effective treatment of spent radioactive ion exchange resins generated during the operation of nuclear facilities is of great significance to reduce its potential hazards to the environment. This work innovatively provides a simple and low-cost molten salt oxidation (MSO) system includes air intake, feeding, waste salt discharge and exhaust gas treatment and analysis system for disposal of spent cation exchange resins (CERs). By studying three feeding amounts that injection of 25 g, 125 g and 1250 g CERs in 10 times under air conditions, the oxidation efficiency of CERs in MSO system was further evaluated. The scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) results indicated the sulfur can be trapped in the melt. Sulfur in functional group can be converted to Na2S and KLi(SO4) via Li2CO3-Na2CO3-K2CO3, which is proved by XRD patterns. The experimental results presented that degradation rates of CERs are 99.31%, 99.80%, and 99.91% in different feeding amounts, respectively. Furthermore, the volume reduction of residue gathered by feeding 1250 g CERs in 10 times was the highest, which can reach 9.19. Therefore, the bench-scale MSO system is a potential and promising treatment for spent CERs volume reduction.

Electrochemical production of HO2- and O2 for sulfide removal from sewage

In this study, a comparative analysis of two electrochemical methods for sulfide control in sewer networks was performed for the first time. In addition, the mechanism of sulfide control by HO2- was elucidated, and an analysis of the device operation and electrolyte selection was performed. The two-electron oxygen reduction reaction (2e--ORR) using untreated gas diffusion electrode (GDE) was superior to the hydrogen evolution reaction (HER) using stainless-steel mesh in terms of cell voltage, product formation, and sulfide suppression. The GDE maintained a stable HO₂⁻ production capacity, achieving a concentration of 4566.6 ± 173.3 mg L⁻¹ with a current efficiency (CE) of 84.13 ± 3.5 %. During the electrolysis period, a stable dissolved oxygen (DO) level in sewage was consistently observed due to continuous in-situ oxygen production in anode. HO2- exhibited a notable increase in sewage pH (10.20 ± 0.01), effectively inhibiting the release of 99.93 % of sulfides. Moreover, the combined treatment of HO2- and DO significantly surpassed that of individual treatments. Seawater treated with cation exchange resin (CER) emerged as the most promising alternative to freshwater as the electrolyte. Overall, this study demonstrates that in-situ generation of HO₂⁻ and oxygen is a more effective strategy for sulfide control in sewer systems.

Novel assessment of molten salt oxidation for cation exchange resin treatment: Effective neutralization of sulfurous gas with Li2CO3-Na2CO3-K2CO3 system

The conventional thermal treatment of cation exchange resin substantially releases sulfurous gases, causing significant equipment corrosion and air pollution. In contrast, the Li2CO3-Na2CO3-K2CO3 as an alkaline molten system effectively neutralizes sulfur gas and mitigates waste gas production inherent in thermal oxidation methods. In the molten salt oxidation process, the volume concentration of SO2 was reduced by 81.7 % compared to that in the traditional thermal oxidation process, and this method reduces the generation of hazardous gases such as CO, CH4, and C2H6. The integration of online gas mass spectrometry and phase stability diagrams for carbonate and sulfur interception products demonstrate excellent thermodynamic stability during the molten salt oxidation (MSO) process. Moreover, a more accurate assessment of the acid gas neutralization capacity of the molten salt system is provided, and the acid gas neutralization capacity of the Li2CO3-Na2CO3-K2CO3 carbonate system can reach 82.58 % at 800 °C. The predominant contributors to acid gas neutralization are Na2CO3 and K2CO3, as evidenced by waste salt composition and ternary phase diagrams. The stable presence of Li2CO3 throughout the MSO process contributes to the lowering of the melting point of the carbonate system to 393 °C.

Epoxidation of neem oil via in situ peracids mechanism with applied ion exchange resin catalyst

Epoxidation of neem oil via in situ peracids mechanism with applied ion exchange resin catalyst

Optimized Lithium(I) Recovery from Geothermal Brine of Germencik, Türkiye, Utilizing an Aminomethyl phosphonic Acid Chelating Resin

ABSTRACT This study investigates the performance of Lewatit TP 260 ion exchange resin for the efficient recovery of lithium (Li(I)) from geothermal water sourced from the Germencik Geothermal Power Plant in Türkiye. A series of batch sorption experiments were performed to evaluate the influence of key parameters, including resin dosage, solution pH, temperature, initial Li(I) concentration, and contact time, on the Li(I) recovery process. The optimal conditions were determined to be a resin dose of 0.5 g per 25 mL of geothermal water, pH in the range of 6–8, and a temperature of 25°C. Under these conditions, the resin achieved a maximum Li(I) recovery rate of 71% from the geothermal water. Sorption isotherms were further analyzed using the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models. Among these, the Langmuir model provided the best fit (R² = 0.9841), suggesting a maximum sorption capacity (qm) of 4.31 mg/g. Continuous recovery experiments conducted in column mode confirmed the practical applicability of Lewatit TP 260, achieving a total sorption capacity of 0.41 mg Li(I)/mL resin. The findings exhibit the potential of this resin as a viable sorbent for sustainable Li(I) extraction from geothermal brines, supporting the development of green energy technologies and contributing to the circular economy.

Kalimate-Associated Gastric Ulcer

Kalimate (calcium polystyrene sulfonate) is a cation-exchange resin commonly used in clinical practice to treat hyperkalemia. However, Kalimate has been demonstrated to also cause serious gastrointestinal injuries, such as colonic necrosis, ulcerations, and perforations, in a subset of patients with chronic renal failure; these cases have been reported with and without the administration of hypertonic sorbitol. These lesions usually occur in the large or small intestine; lesions occurring in the stomach are rarely reported. We present the case of a 62-year-old woman with very large Kalimate-induced gastric ulcers that were mistaken for advanced gastric cancer in patients with chronic renal failure who had been taking Kalimate for the previous 3 months. The patient was successfully treated by discontinuing Kalimate and initiating a proton pump inhibitor.

Adsorption of per- and polyfluoroalkyl substances on biochar derived from municipal sewage sludge

Granular activated carbon (GAC) and ion exchange resin (IXR) are widely used as adsorbents to remove PFAS from drinking water sources and effluent waste streams. However, the high cost associated with GAC and IXR generation has motivated the development of less expensive adsorbents for treatment of PFAS-impacted water. Thus, the objective of this research was to create an economically viable and sustainable PFAS adsorbent from sewage sludge. Stepwise pyrolysis at temperatures from 300 °C to 1000 °C yielded biochars whose specific surface area (SSA) and porosity increased from 41 to 148 m2/g, and from 0.062 to 0.193 cm3/g, respectively. On a per organic char basis, the SSA of the biochar was as high as 1183 m2/g, which is comparable to commercially-available activated carbons. The adsorption of perfluorooctane sulfonic acid (PFOS) on sludge biochar increased with increasing pyrolysis temperature, which was positively correlated with increasing porosity and SSA. When 1000 °C processed biochar was tested with a mixture of eight PFAS, preferential adsorption of longer carbon chain-length species was observed, indicating the importance of PFAS hydrophobic interactions with the biochar and the availability of a wide range of mesopores. The adsorption of each PFAS was dependent upon both chain length and head group, with longer chain-length species exhibiting greater adsorption than shorter chain-length species, along with greater adsorption of species with sulfonic acid head groups compared to their chain length counterparts with carboxylic acid head groups. These findings demonstrate that biochar derived from municipal solid waste can serve as a cost-effective and sustainable adsorbent for the removal of PFOS and PFAS mixtures from source waters. The circular economy benefits and waste reduction potential associated with the use of sewage sludge-derived biochar supports the development of a viable sludge-derived biochar for the removal of PFAS from water.

Enrichment of deoxynojirimycin in mulberry using cation exchange resin: Adsorption/desorption characteristics and process optimization

Deoxynojirimycin (DNJ) is an α-glucosidase inhibitor with high food values. However, the complex and costly enrichment processes have greatly prevented its application. Herein, this study aimed to propose a simple and efficient enrichment process for DNJ from Morus alba L. extracts using cation exchange resins. The LSI and D113 resins were chosen due to their excellent adsorption and desorption properties. The adsorption characteristics agreed with the pseudo-first-order kinetic model and the Langmuir isotherm model. This adsorption was chemisorption, spontaneous, endothermic and entropy-driven. Furthermore, the concentration and pH of the extracts, desorption solvent, breakthrough and elution curves, sample loading and elution rate were investigated to optimize the enrichment process by resin column chromatography. The results also showed that the purity of DNJ was improved to 44.00 % with a total recovery of 78.21 % using the LSI-D113 combination strategy. This research demonstrated the industrial feasibility of DNJ enrichment using cation exchange resins.

Enhancing Resource Recovery through Electro-Assisted Regeneration of an Ammonia-Selective Cation Exchange Resin

Enhancing Resource Recovery through Electro-Assisted Regeneration of an Ammonia-Selective Cation Exchange Resin

Opportunity and Challenge of Advanced Porous Sorbents for PFAS Removal.

Per- and polyfluoroalkyl substances (PFASs), comprising over 9,000 persistent synthetic organic contaminants, are extensively found in the environment and pose significant risks to both human and ecological health. Among the strategies for addressing PFAS contamination, adsorption processes have proven to be cost-effective. Traditional sorbents such as ion-exchange resins and activated carbon have been found to exhibit low adsorption capacities and slow equilibration times. Recent innovations in porous materials, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and porous organic polymers (POPs), however, offer significant improvements in the efficiency of PFAS adsorption. This review thoroughly examines the latest advancements in these materials, analyzing their mechanisms of adsorption, and concludes by suggesting directions for future research that could further enhance their effectiveness in PFAS management.

Efficient synthesis of acetylsalicylic acid over Y-immobilized cation exchange resin conjoined ultrasonic collaborative method under mild conditions

Efficient synthesis of acetylsalicylic acid over Y-immobilized cation exchange resin conjoined ultrasonic collaborative method under mild conditions

The efficient degradation of carbamazepine by Cu-Fe bimetallic composite carbon derived from the waste cation exchange resins: Mechanism, ecotoxicity, and continuous flow catalysis

The Cu-Fe bimetallic composite carbon (CuFeO2@CR) was synthesized by using the waste cation exchange resins as the carbon source to degrade carbamazepine (CBZ) by activating peroxymonulfate (PMS). Results found that 91.3 % of CBZ was degraded under the optimal condition ([PMS] = 0.2 g/L, [CuFeO2@CR] = 0.3 g/L, T = 25℃). CuFeO2@CR could efficiently degrade CBZ at pH 3.03–9.02 and maintain the degradation at 83.6 % in the fifth cycle. The reactive oxygen species (ROS) were SO4•−, •OH, and 1O2 with the relative contribution of 35 %, 29 %, and 36 %, respectively. DFT calculation demonstrated that CuFeO2@CR exhibited a preferential affinity for PMS and greater transfer electrons capacity than CR. Three reaction pathways were proposed in the CuFeO2@CR/PMS system, and the degradation could effectively reduce the toxicity into non-toxic. The continuous flow catalytic experiment indicated the promising application in the treatment of antibiotic wastewater. This work provides guidance and theoretical support for CBZ degradation mechanisms.

Elution behavior of carbohydrates using core-shell ion-exchange resin St-60 with different numbers of methylene groups in the porous shell and a constant cross-linking degree of 55%

Elution behavior of carbohydrates using core-shell ion-exchange resin St-60 with different numbers of methylene groups in the porous shell and a constant cross-linking degree of 55%

Boosting the rate performance of zinc-iodine batteries via electrostatic adsorption and catalysis of strong base ion resin grafted with cobalt phthalocyanine

The shuttle of iodine species is considered the obstacle to the application of aqueous zinc iodine (Zn-I2) batteries. Although cathode hosts with electrostatic adsorption to iodine species have been developed to suppress the shuttle effect of polyiodide, the strong interaction between polyiodide and hosts significantly slow down the kinetics of oxidation–reduction of iodine species. Here, a host with strong constraint and catalytic effects on iodine species based on strong base ion exchange resin is established, while the interaction and catalytic performance of hosts on iodine species is regulated by adjusting the functional group structure and the loading amount of quaternary ammonium cobalt phthalocyanine (QACoPc). UV–vis spectroscopy and electrochemical characterization confirm that the iodine host suppresses the shuttle of polyiodide. Moreover, the kinetic analyses reveal that the introduction of QACoPc into host improves the redox kinetic process of iodine species. Consequently, the polymer-based Zn-I2 battery exhibits stable cycling ability (98.9 % retention rate after 2000 cycles at the current density of 10 C, 1 C: 160 mAh g−1) and excellent rate performance (150.6 mAh g−1 at 1 C and 105.9 mAh g−1 at 50 C) due to the strong constraint and catalytic effects of host on iodine species.

An Alternative Concept in Making Hybrid Flow Batteries into Dendrite-Free Full-Flow Batteries

: In this study, the author proposes an alternative concept of using electrostatic force of cation-exchange resin to attract metal ions and nanoscale conductors onto the polymer matrix to conduct the electrons for the plating/stripping of the metal species. Due to the even distribution of the positively-charged functional groups inside the cation-exchange resin, metal formation can also be well distributed and safety issue caused by metal dendrite can be eliminated. By applying this transformative concept, various hybrid flow batteries could be “upgraded” to dendrite-free full-flow batteries. Interestingly, this new concept could also be generalized for all metal-based aqueous and nonaqueous hybrid systems to upgrade them into next-generation full-flow battery systems. This work offers an alternative concept to deliver unprecedented battery systems and the proof-of-concept would be more easily implemented than anticipated.

Adsorption Equilibrium, Kinetics, and Column Breakthrough Data of Acetic Acid, Butyric Acid, and Lactic Acid on the IRN-78 Ion-Exchange Resin at Initial pH (∼3–7) and Temperature (25–55 °C)

Adsorption Equilibrium, Kinetics, and Column Breakthrough Data of Acetic Acid, Butyric Acid, and Lactic Acid on the IRN-78 Ion-Exchange Resin at Initial pH (∼3–7) and Temperature (25–55 °C)

High purity alumina production by leaching-ion exchange process: Design and flowchart proposal

Growing demand for high-purity Al2O3 for the electronic market and green energy production, allied with the need to decrease waste generation and dam use, will impact the future of mining, and new processes should be developed. The present study aimed to develop a hydrometallurgical process to obtain high-purity Al2O3 from bauxite. Among the samples studied, BX03 had the highest Al2O3 (63.8 %) and lowest Fe2O3 content (4.3 %). Different acids were evaluated – H2SO4, HCl, HNO3, and H3PO4 – and the H2SO4 reaction achieved all Al leaching with the best technical–economic analysis (TEA). Purification experiments were carried out with ion exchange resins in batch reactions. The best purification parameters were 4 h of contacting time and mass of resin/volume of solution ratio as 1/10 at 45 °C in two stages. The iminodiacetate resin (Lewatit TP 207) achieved the best results and removed all Fe ions without losses. High-purity Al2O3 was further obtained by precipitation with NH4OH after calcination. Considering the leaching step costs, the proposed process may achieve up to US$ 63,022.91 in profit.

In silico mediated workflow for rapid development of downstream processing: Orthogonal product-related impurity removal for a Fc-containing therapeutic

Therapeutic formats derived from the monoclonal antibody structure have been gaining significant traction in the biopharmaceutical market. Being structurally similar to mAbs, most Fc-containing therapeutics exhibit product-related impurities in the form of aggregates, charge variants, fragments, and glycoforms, which are inherently challenging to remove. In this work, we developed a workflow that employed rapid resin screening in conjunction with an in silico tool to identify and rank orthogonally selective processes for the removal of product-related impurities from a Fc-containing therapeutic product. Linear salt gradient screens were performed at various pH conditions on a set of ion-exchange, multimodal ion-exchange, and hydrophobic interaction resins. Select fractions from the screening experiments were analyzed by three different analytical techniques to characterize aggregates, charge variants, fragments, and glycoforms. The retention database generated by the resin screens and subsequent impurity characterization were then processed by an in silico tool that generated and ranked all possible two-step resin sequences for the removal of product-related impurities. A highly-ranked process was then evaluated and refined at the bench-scale to develop a completely flowthrough two-step polishing process which resulted in complete removal of the Man5 glycoform and aggregate impurities with a 73% overall yield. The successful implementation of the in silico mediated workflow suggests the possibility of a platformable workflow that could facilitate polishing process development for a wide variety of mAb-based therapeutics.