Commercial Ion Exchange Resin Research Articles

Representative longevity testing of direct air capture materials

Direct-air CO2 capture (DAC) is a rapidly expanding field of research driven by a growing need for net-negative technologies. One leading class of materials for DAC isamine-based adsorbents, however these may have limited lifetime due to oxidative degradation. Material longevity is a critical parameter; however, most studies test the stability of thesematerials under inert atmospheres, removing the oxidation pathway. Consequently, more realistic longevity testing is needed.This work presents a method using ambient air andpartial vacuum conditions to assess the stability of DAC materials realistically. A custom-built, automated system was developed whereby CO2 adsorption was conducted in ambient air and desorption under vacuum.In this study, the novel method presented here is compared to a TGA methodfor analysis of the commercial ion exchange resin Lewatit VP OC 1065. A novel crosslinked polyamine designated here as CA-1 is also examined using the system undervarious conditions.The method involves the measurement and re-measurement of adsorption capacity between adsorption/desorption cycles. The Lewatit resin was cycled 180 times with desorption at 80 °C and 100 mbar absolute. In this test, itlost 31.20 % of original capacity, contrasted with a 5.47 % loss from the inert TGA method. The CA-1 crosslinked polyamine was thencycled 500 times at three sets of desorption conditions: 80 °C and atmospheric pressure, 80 °C and 500 mbar absolute, and 75 °C and 200 mbar absolute. The sample at 200 mbar lost only 2.79 % original uptake, compared to 28.74 % in atmospheric pressure.

Pseudo-affinity capture of K. phaffii host cell proteins in flow-through mode: Purification of protein therapeutics and proteomic study

K. phaffii is a versatile expression system that is increasingly utilized to produce biological therapeutics – including enzymes, engineered antibodies, and gene-editing tools – that feature multiple subunits and complex post-translational modifications. Two major roadblocks limit the adoption of K. phaffii in industrial biomanufacturing: its proteome, while known, has not been linked to downstream process operations and detailed knowledge is missing on problematic host cell proteins (HCPs) that endanger patient safety or product stability. Furthermore, the purification toolbox has not evolved beyond the capture of monospecific antibodies, and few solutions are available for engineered antibody fragments and other protein therapeutics. To unlock the potential of yeast-based biopharmaceutical manufacturing, this study presents the development and performance validation of a novel adsorbent – PichiaGuard – functionalized with peptide ligands that target the whole spectrum of K. phaffii HCPs and designed for protein purification in flow-through mode. The PichiaGuard adsorbent features high HCP binding capacity (∼25 g per liter of resin) and successfully purified a monoclonal antibody and an ScFv fragment from clarified K. phaffii harvests, affording > 300-fold removal of HCPs and high product yields (70–80%). Notably, PichiaGuard outperformed commercial ion exchange and mixed-mode resins without salt gradients or optimization in removing high-risk HCPs – including aspartic proteases, ribosomal subunits, and other peptidases – thus demonstrating its value in modern biopharmaceutical processing.

Role of cationic surfactants in palladium adsorption of commercial ion exchange resins using electroless plating solutions

AbstractThis work investigates the role of cationic surfactants in the adsorption of palladium ions from synthetic electroless plating solutions using a commercial resin, Lewatit TP-214. This would also help us in determining the batch adsorption experiments elaborated on the optimal parameters such as surfactant concentration, pH, dosage, initial metal ion concentration for the development of an ion-exchange resin with high metal removal efficiency. Critical micelle concentration (CMC) appears to be an important parameter in determining the adsorption behavior of ion-exchange resins with palladium ions. Equilibrium models were measured for their fitness with the obtained Pd (II) batch adsorption characteristics and Freundlich isotherm confirms the heterogeneous Pd (II) adsorption on Lewatit TP-214. FTIR analysis confirmed that the Pd (II) metal uptake of Lewatit TP-214 resin largely depends on amine groups (-NH2+ and -NH+) and the donor atoms attached to cationic surfactant. The optimized choice of adsorption parameters (pH of 8, dosage of 1 g/L, and contact time of 300 min) of Lewatit TP-214 adsorbent provided the highest metal uptake and removal efficiency as 201.7 mg/g and 90.16%, respectively, for the lowest Pd concentration of 300 mg/L.

Rational design of the nanocomposite by in-situ sub-10 nm La(OH)3 formation for selective phosphorus removal in waters

Phosphate removal by nanocomposite is a promising approach in water remediation. But it is still challenged by the small size nanoparticles formation and kinetic diffusion under the nanopore confinement. Herein, we report a different strategy, which relies on the deposition of nano-La(OH)3 particles inside the porous biomass Artemia Cyst-shells matrix. The charged amino acid components of matrix drivers for the in-situ growth of rod-like nano-La(OH)3 with size below 10 nm, while the broad-porous skeleton structures enable and accelerate the accessibility of trace phosphate to nano-La(OH)3 sorption sites available, resulting in the efficient and fast phosphate removal performance. This nanocomposite exhibited excellent adsorption capacity as high as 180.5 mg/g, which is beyond of most adsorbents by recent-ten-year survey. It also revealed superior selectivity against various competing ions with a distribution coefficient (Kd) up to ∼ 34000 mL/g, exceeding commercial ion-exchange resin by 15 times and outdoing 10 times the performance of well-known Fe based nanocomposites Lewatit FO36. An outstanding treatment capacity of 10980 L/kg under the continuous operation and the satisfactory regeneration property (> 95 %) further proves its applicability. This technology provides a new perspective approach for nanocomposite design and wastewater determination. It is also promising alleviating problems of trace phosphate deep purification in drinking water and wastewater medium.

Revealing the roles of biomass components in the biosorption of heavy metals in wastewater by various chemically treated hemp stalks

BackgroundLead is a typical heavy metal contaminant that can result in severe health problems even at ultralow concentrations. Current state-of-the-art technology relies on expensive synthetic ion-exchange resins, but hemp can be an economical and ecological sustainable alternative to synthetic sorbents. In addition, the roles of various components in biomass are not clear in the biosorption process. MethodsThe various roles of biomass components in the biosorption of heavy metals were determined by investigating removing aqueous lead(II) ions by biosorbents derived from raw and chemically treated hemp stalks, such as delignification and mercerization. Various biosorbents were characterized by FTIR, SEM, and XRD to rationalize the biosorption process. Significant findingsLead(II) biosorption exhibited pseudo-second-order kinetics with intraparticle diffusion as the rate-limiting step, and the biosorption process was exothermic and favorable. Based on the biosorption capacities of various chemical-treated biosorbents, the capacities for cellulose, hemicellulose, and lignin were 277.39, 878.46, and 17.96 mg/g. Due to its hydrophilic nature and multi-functional groups, hemicellulose exhibited superior performance to commercial ion-exchange resins. Lignin is not suitable as biosorbents for removing aqueous heavy metals because of its hydrophobic property. The obtained results demonstrate the feasibility of using biosorbents derived from hemp stalks as sustainable and economical materials for wastewater treatment.

Catalyst screening and reaction kinetics of liquid phase DME synthesis under reactive distillation conditions

While conventional DME synthesis is exclusively operated in a gas phase heterogenous reaction system, reactive distillation unveils the potential for a process intensified, compact and efficient DME production. In a catalyst screening, various solid acid catalysts were examined in the liquid phase dehydration of methanol to DME. Ion exchange resins proofed to be more active than zeolites and more stable than perfluorsulfonic acids. Reaction kinetics on the two most promising commercial ion exchange resins, the oversulfonated resin Amberlyst® 36 and the chlorinated resin TreverlystCAT400 were studied in a profile reactor setup over the full range of water fractions relevant for DME reactive distillation processes. CAT 400 was found to show a lower activity than Amberlyst® 36 at identical temperatures, however, due to the higher thermal stability, significantly higher conversions could be achieved. In the kinetic fitting, it was found that the conventional Eley-Rideal and Langmuir-Hinshelwood mechanisms are not capable to describe the experimental data over the wide range of water fractions due to the highly non-linear inhibition by water resulting from the distinct swelling properties of ion exchange resins. To account for this behavior, a new kind of kinetic model with dedicated water inhibition term is introduced and discussed. This model allows the precise description of reaction kinetics over the whole studied operating range for both investigated catalysts and reflects the temperature-dependent inhibition by water. The new kinetic model is an essential building block for the design of industrial scale DME reactive distillation processes.

Recovery of Lead (II) Ions from Aqueous Solutions Using G-26 and MTS9570 Resins with Sulfonic/Phosphonic Functional Groups

This study presents Pb(II) recovery/removal from water solutions using two different commercial ion-exchange resins, i.e., Dowex G-26 with sulfonic functional group and Puromet™ MTS9570 with sulfonic and phosphonic functional groups. Overall, 100% Pb(II) recovery/removal by both resins was obtained at solution pH 3.5, resin dosage 25 g/L, adsorption time 30 min, room temperature, and initial Pb(II) concentration 1000 mg/L. Langmuir, Freundlich, and Temkin isotherms were used to model the experimental data. The mechanism of the adsorption process was investigated using kinetic and thermodynamic models. The experimental data fitted very well with the pseudo-second-order kinetic model, and thermodynamic analysis showed that the adsorption of Pb(II) from acidic solution onto both resins was a spontaneous and endothermic process in nature. Regeneration of the resins loaded with lead ions was tested for three cycles to evaluate the resin recyclability. Good stability of G-26 and performance degradation of MTS9570 resin was observed.

Functionality screening to help design effective materials for radioiodine abatement

This paper is part of a growing body of research work looking at the synthesis of an optimal adsorbent for the capture and containment of aqueous radioiodine from nuclear fuel reprocessing waste. 32 metalated commercial ion exchange resins were subjected to a two-tier screening assessment for their capabilities in the uptake of iodide from aqueous solutions. The first stage determined that there was appreciable iodide capacity across the adsorbent range (12-220mg·g-1). Candidates with loading capacities above 40mg·g-1 were progressed to the second stage of testing, which was a fractional factorial experimental approach. The different adsorbents were treated as discrete variables and concentrations of iodide, co-contaminants and protons (pH) as continuous variables. This gave rise to a range of extreme conditions, which were representative of the industrial challenges of radioiodine abatement. Results were fitted to linear regression models, both for the whole dataset (R 2 = 59%) and for individual materials (R 2 = 18-82%). The overall model determined that iodide concentration, nitrate concentration, pH and interactions between these factors had significant influences on the uptake. From these results, the top six materials were selected for project progression, with others discounted due to either poor uptake or noticeable iodide salt precipitation behaviour. These candidates exhibited reasonable iodide uptake in most experimental conditions (average of >20mg·g-1 hydrated mass), comparing favourably with literature values for metallated adsorbents. Ag-loaded Purolite S914 (thiourea functionality) was the overall best-performing material, although some salt precipitation was observed in basic conditions. Matrix effects not withstanding it is recommended that metalated thiourea, bispicolylamine, and aminomethylphosphonic acid functionalized silicas warrant further exploration.

Hydrolytically Stable Ionic Fluorogels for High-Performance Remediation of Per- and Polyfluoroalkyl Substances (PFAS) from Natural Water.

PFAS are known bioaccumulative and persistent chemicals which pollute natural waters globally. There exists a lack of granular sorbents to efficiently remove both legacy and emerging PFAS at environmentally relevant concentrations. Herein, we report a class of polymer networks with a synergistic combination of ionic and fluorous components that serve as granular materials for the removal of anionic PFAS from water. A library of Ionic Fluorogels (IFs) with systematic variation in charge density and polymer network architecture was synthesized from hydrolytically stable fluorous building blocks. The IFs were demonstrated as effective sorbents for the removal of 21 legacy and emerging PFAS from a natural water and were regenerable over multiple cycles of reuse. Comparison of one IF to a commercial ion exchange resin in mini-rapid small-scale column tests demonstrated superior performance for the removal of short-chain PFAS from natural water under operationally relevant conditions.

Hydrolytically Stable Ionic Fluorogels for High‐Performance Remediation of Per‐ and Polyfluoroalkyl Substances (PFAS) from Natural Water

AbstractPFAS are known bioaccumulative and persistent chemicals which pollute natural waters globally. There exists a lack of granular sorbents to efficiently remove both legacy and emerging PFAS at environmentally relevant concentrations. Herein, we report a class of polymer networks with a synergistic combination of ionic and fluorous components that serve as granular materials for the removal of anionic PFAS from water. A library of Ionic Fluorogels (IFs) with systematic variation in charge density and polymer network architecture was synthesized from hydrolytically stable fluorous building blocks. The IFs were demonstrated as effective sorbents for the removal of 21 legacy and emerging PFAS from a natural water and were regenerable over multiple cycles of reuse. Comparison of one IF to a commercial ion exchange resin in mini‐rapid small‐scale column tests demonstrated superior performance for the removal of short‐chain PFAS from natural water under operationally relevant conditions.

Development of Adsorptive Membranes for Selective Removal of Contaminants in Water.

The presence of arsenic and ammonia in ground and surface waters has resulted in severe adverse effects to human health and the environment. Removal technologies for these contaminants include adsorption and membrane processes. However, materials with high selectivity and pressure stability still need to be developed. In this work, adsorbents and adsorptive membranes were prepared using nanostructured graphitic carbon nitride decorated with molecularly imprinted acrylate polymers templated for arsenate and ammonia. The developed adsorbent removed arsenate at a capacity and selectivity similar to commercial ion-exchange resins. Ammonia was removed at higher capacity than commercial ion exchange resins, but the adsorbent showed lower selectivity. Additionally, the prepared membranes removed more arsenate and ammonia than non-imprinted controls, even in competition with abundant ions in water. Further optimization is required to improve pressure stability and selectivity.

Ion Exchange Resins to Reduce Boron in Desalinated Seawater for Irrigation in Southeastern Spain

Desalinated seawater (DSW) can provide water resources for irrigation in coastal regions where freshwater is scarce. Reverse osmosis (RO) is the most common technique to obtain DSW worldwide. Nevertheless, using DSW for irrigation could pose an agronomic risk as RO permeates may have a boron concentration above the phytotoxicity thresholds of certain crops, such as woody crops (0.5 to 1.0 mg/L). In this study, an on-farm ion exchange resin system with an average flow of 1 m3/h, designed to reduce the boron concentration of DSW, was evaluated from a technical and economic perspective. The impact of variations in the feed water and operating temperatures on the boron reduction process was assessed. The results show that the system can provide an outflow with a boron concentration below the threshold of 0.5 mg/L over 92 h of operation, with boron rejections of up to 99% during the first 41 h. The estimated cost of boron removal with the on-farm system of the trial was EUR 0.992/m3. However, this cost is expected to decrease to EUR 0.226/m3 for a commercial ion exchange resin (IX) plant (20 m3/h), highlighting the importance of the scale factor. Our results provide novel guidance on the viability of using boron removal IX systems for farms irrigated with DSW, when it is provided by coastal plants with boron concentrations above the crop tolerance.

Use of Ion-Exchange Resins to Adsorb Scandium from Titanium Industry’s Chloride Acidic Solution at Ambient Temperature

Scandium metal has generated a lot of interest during the past years. This is due to the various crucial applications it has found ground in and the lack of production in countries outside China and Russia. Apart from rare earth ores, scandium is present in a variety of wastes and by-products originating from metallurgical processes and is not currently being sufficiently valorised. One of these processes is the production of titanium dioxide, which leaves an acidic iron chloride solution with a considerably high concentration of scandium (10–140 ppm) and is currently sold as a by-product. This research aims to recover scandium without affecting the solution greatly so that it can still be resold as a by-product after the treatment. To achieve this, two commercial ion-exchange resins, VP OC 1026 and TP 260, are used in the column setup. Their breakthrough curves are plotted with mathematical modelling and compared. Results indicate that VP OC 1026 resin is the most promising for Sc extraction with a column capacity of 1.46 mg/mL, but Zr, Ti, and V coextract have high capacities, while Fe does not interfere with the adsorption.

Speciality commercial ion exchange resins for use in nuclear industries for antimony removal: A systematic study

Antimony, a metalloid, is present in effluents generated in diverse industries. Antimony is of high concern in nuclear industries in particular due to the presence of its active isotopes. Safe management of such antimony containing effluents is a crucial problem which currently lacks viable solution. One of the reasons is the lack of availability of well-studied antimony removal agents. In this context, three commercially available speciality ion exchange resins (Tulsion® CH-87, CH-90 and CH-99) were evaluated for their antimony removal ability. Among the three resins evaluated, Tulsion® CH-99, a polyhydroxy amine-based resin, showed favourable results and its antimony binding properties were studied in detail. Tulsion® CH-99 showed fast uptake kinetics, selectivity, and antimony removal under wide solution pH conditions. Saturation capacities obtained were found to be 83 mg.g−1 (0.68 mmol.g−1) for Sb(V) and 73.1 mg.g−1 (0.6 mmol.g−1) for Sb(III). Batch and column studies carried out with simulated decontamination and reprocessing effluents of nuclear industry showed selective antimony uptake. Antimony uptake from typical reprocessing effluent (referred to as High Level Waste (HLW)), which has highly acidic and complex matrix (3 M HNO3 and a suite of competing ions such as Cr(VI)), demonstrated the high stability and antimony selectivity of the investigated resin.

Fixed-bed column study of phosphate adsorption using immobilized phosphate-binding protein

Bio-adsorption using high-affinity phosphate-binding proteins (PBP) has demonstrated effective phosphorus removal and recovery in batch-scale tests. Subsequent optimization of design and performance of fixed-bed column systems is essential for scaling up and implementation. Here, continuous-flow fixed-bed column tests were used to investigate the adsorption of inorganic phosphate (orthophosphate, Pi) using phosphate-binding proteins immobilized on resin (PBP–NHS) targeting Pi removal to ultra-low levels followed by recovery. Time to breakthrough decreased with higher influent Pi concentration, smaller bed volume, and higher influent flow rates. The Thomas and Yoon-Nelson breakthrough models adequately described PBP-NHS resin performance with a correlation coefficient of R2 > 0.95. The sharp S-shape of the breakthrough curves for both Pi-only solution and multi-ion solution indicated highly favorable and selective separation of Pi using PBP-NHS resin, beyond that achieved using LayneRT™, a commercial ion exchange resin. The Pi adsorption capacity of the PBP-NHS column was unaffected by competing anions, whereas capacity of the LayneRT™ column dropped by 20%. Tertiary wastewater effluent was also successfully treated in PBP-NHS column tests with a typical S-shaped breakthrough curve. Operating the fixed-bed column in multi-cycle mode evidenced the reusability of PBP-NHS resin with no significant decline in column performance. The results of this study contribute to efforts to scale up designs of PBP-NHS adsorption systems.

THE STUDY OF THE SORPTION PROPERTIES OF FILTERING MATERIALS BASED ON TITANIUM PHOSPHATE - POROUS TITANIUM COMPOSITION

Inorganic sorbents are more selective in comparison with commercial ion exchange resins towards of metal ions. However, inorganic sorbents characterized not high kinetic properties. One of the way to increase the kinetic rate of inorganic sorbents is to reduce the particle size of these materials, other way is synthesizing inorganic sorbents as porous products from powder materials. A sample of such inorganic sorbents is titanium phosphate of various compositions. Studying the properties of microfilters based on composition titanium phosphate - porous titanium has been developed. The sorbents based on acidic titanium phosphate Ti(HPO4)2∙H2O were used for filtering solution with Fe(II) content. It is found that the number of impregnations with inorganic sorbent modificator is important and influence filtration process. The obtained results demonstrated that after the first impregnation of porous material with a smaller pore size, it is possible to obtain such sorbent as a mass content of powder material. By varying the ionic form of titanium phosphate, the porosity of titanium, the amount of impregnation, it could be possible effect on the sorption Fe(II). The sorption properties of titanium-titanium phosphate microfilters were studied by potentiometric titration in the NaCl-NaOH system, as well as the sorption of Fe2+ ions. The degree of purification for Fe(II) from solution with a concentration of 10 mg/l is 64 %. Application an electric potential to the microfilter of porous titanium - phosphate titanium increases the degree of purification of Fe(II) to 88 %.

Separation of Indium from Acid Sulfate‐Containing Solutions by Ion Exchange with Impregnated Resins

AbstractIndium separation using ion exchange resins from acidic polymetallic and very diluted solutions are investigated. Since the selectivity of commercial ion exchange resins have proven to be too low for an effective separation from solutions with high content of other metals, Lewatit® TP 208 was impregnated with common extractants to enhance its properties. By resin impregnation with D2EHPA and Cyanex 272, not only the selective indium recovery was reached but also the resin capacity was increased approx. two times. The best loading and elution performance were shown by Cyanex 272‐impregnated Lewatit® TP 208, increasing the indium purity in the eluate from 0.75 % to 85 %.

Microwave-assisted melamine-based polyaminals and their application for metal cations adsorption

Three new cross-linked melamine-based polyaminal networks containing phenyl (MA-iPh), pyridine (MA-Py) or thiophene (MA-Th) moieties were easily prepared by microwave irradiation (MW) in shorter reaction times (between 1.5 and 4 h) than conventional heating (72 h). The networks showed high nitrogen content (27–37%), specific surfaces between 34 and 424 m2g−1 and high thermal stability (300 °C). The adsorption capacity of these polyaminals was determined over different toxic metals such as Cr(VI), Cu(II), Cd (II) and Pb(II) at different pH. The results showed greater chromium adsorption capacity in acid medium (pH 2), while the divalent cations were mainly adsorbed at pH 5. MA-Py that displayed the highest nitrogen content (37%) and highest specific surface area (424 m2g−1) also showed the highest adsorption capacities of this series, with values of 27.22, 26.42, and 53.13 mg/g for Cr(VI), Cd(II) and Pb(II); respectively. Additionally, MA-Py and MA-iPh with adsorption capacities of 29.12 and 25.02 mgg−1 for Cr(VI) and Cd(II), were competitive in terms of adsorption capacities regarding commercial ion exchange-resins which shown adsorptions in the range 13.7–21.3 mg/g.

Dihydroxyacetone Production: From Glycerol Catalytic Oxidation with Commercial Catalysts to Chromatographic Separation

A process for catalytic production of dihydroxyacetone through glycerol oxidation and dihydroxyacetone purification by chromatographic processes is herein presented. Glycerol oxidation over commercial Pt/AC and Pt–Bi/AC catalysts was performed on a batch reactor operating under base-free conditions, using water as a solvent and oxygen as the oxidant agent. The highest dihydroxyacetone yield obtained was 36%, using the Pt5%-Bi1.5%/AC catalyst, whereas the monometallic Pt/AC catalyst was selective to glyceric acid. It is herein reported for the first time dihydroxyacetone separation from unreacted glycerol and reaction byproducts (organic acids). Two commercial polystyrene-divinylbenzene ion-exchange resins were used as a stationary phase, one in the hydrogen form and the other in the calcium form, and water was used as the mobile phase. Adsorption equilibrium data for the species present in the reaction mixture were determined in both resins through single-component adsorption breakthrough experiments. A continuous chromatographic separation process was designed based on the simulated moving bed (SMB) technology and simulated using the gPROMS model builder software. A two SMB cascade was then considered, performing the pseudobinary mixture separation on the first SMB. The extract stream from the first SMB containing dihydroxyacetone and glycerol was fed to the second SMB, obtaining dihydroxyacetone with a purity of 97%. Considering the overall unit, a dihydroxyacetone productivity of 64 kgDHA (LAds day)−1 was obtained with an eluent consumption of 1218 LDes kgDHA–1.

New Bio-Based Furanic Materials Effectively Absorb Metals from Water and Exert Antimicrobial Activity.

Development of sustainable bio-based materials for removal of toxic contaminants from water is a high priority goal. Novel bio-based binary and ternary copolymers with enhanced ion-exchange, adsorption and antibacterial properties were obtained by using plant biomass-derived diallyl esters of furandicarboxylic acid (FDCA) as crosslinking agents and easily available vinyl monomers. The synthesized copolymer materials showed higher sorption capacities for NiII , CoII and CuII compared to the commercial ion-exchange resins, and they maintained their high metal adsorption capacities for over 10 cycles of regeneration. The synthesized copolymer gels containing 1-5 wt % of the crosslinker showed excellent water absorption capacities. The synthesized copolymers with 1 % crosslinker content showed swelling ratios high enough to also act as moisture absorbents. Synthesized copolymers with crosslinker content of 10 wt % performed as contact-active antibacterials by inhibiting the growth of Gram-positive (S. aureus) and Gram-negative bacteria (E. coli, K. pneumonia) in suspension tests.