Commercial Ion Exchange Resin Research Articles

Selective and Efficient Removal of Fluoride from Water: In Situ Engineered Amyloid Fibril/ZrO2 Hybrid Membranes.

We report a new strategy for efficient removal of F- from contaminated water streams, and it relies on carbon hybrid membranes made of amyloid fibril/ZrO2 nanoparticles (<10 nm). These membranes exhibit superior selectivity for F- against various competitive ions, with a distribution coefficient (Kd ) as high as 6820 mL g-1 , exceeding commercial ion-exchange resins (IRA-900) by 180 times and outdoing the performance of most commercial carbon-activated aluminum membranes. At both low and high (ca. 200 mg L-1 ) F- concentrations, the membrane efficiency exceeds 99.5 % removal. For real untreated municipal tap water (ca. 2.8 mg L-1 ) under continuous operating mode, data indicates that about 1750 kg water m-2 membrane can be treated while maintaining drinking water quality, and the saturated membranes can be regenerated and reused several times without decrease in performance. This technology is promising for mitigating the problem of fluoride water contamination worldwide.

Highly Defective UiO-66 Materials for the Adsorptive Removal of Perfluorooctanesulfonate

Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant that is bioaccumulative and toxic. While its use in most countries has been restricted to certain industrial applications due to environmental and health concerns, chrome plating and semiconductor manufacturing facilities are industrial point sources of PFOS-containing wastewater. Current remediation technologies are ineffective at treating these highly concentrated industrial effluents. In this work, UiO-66 metal–organic frameworks (MOFs) of several defect concentrations were studied as sorbents for the removal of PFOS from concentrated aqueous solutions. PFOS sorption isotherms indicated that defective UiO-66, prepared with HCl as a modulator, had a maximum Langmuir sorption capacity of 1.24 mmol/g, which was ∼2× greater than powdered activated carbon (PAC), but ∼2× less than that of a commercial ion-exchange resin. Defective UiO-66 adsorbed PFOS 2 orders of magnitude faster than the ion-exchange resin. Large pore defects (∼16 and ∼20 A) ...

The Acid and Radiation Stability of Some Commercial Ion Exchangers

This paper addresses the stability of commercial cation exchangers when in contact with nitric acid that are under consideration for UCLan’s alternative reprocessing process. The paper describes the acid tolerance of four commercial ion exchange resins when exposed to 7M nitric acid for one year. The acid degradation was measured by FT-IR and TGA before and post acid exposure. Zirconium uptake was measured pre and post acid exposure as a means of determining degradation of functional sites. The resins undergo a degree of acid degradation depending on their chemical composition i.e., polymeric backbone, in some instances loss of functionality but also the introduction of new functional sites. The likely radiation dose that ion exchange resins would receive from spent nuclear fuel dissolver liquor and from adsorbed radioactive cesium 137 were estimated. It was inferred that the radiation dose the exchangers would receive from adsorbed cesium isotopes would be comparatively low when compared with the radiation background of the spent fuel dissolver liquor.

Synthesis and Characterization of Methyl Amino Polystyrene as Resin Material of Chromatography

Ion-exchange chromatography has been widely used in various separation process and purification. Commercial ion-exchange resin mostly uses polystyrene as stationer phase. This study reviewed the synthesis of cation-exchange resin with polystyrene as starting material. Polystyrene must be activated in order to make one of aromatic carbon chains being able to be binding with acetamide n-hidroxymethyl electrophilic. Polystyrene activation was conducted through two stages, i.e. (1) the formation of amidomethyl polystyrene (AMDP), and followed with (2) elimination of acyl group. The activation of polystyrene generated white methylamino polystyrene (MAP) resin, of which its characterization used spectrophotometry UV, Fourier Transform-Infrared (FTIR), and density of MAP resin confirmed by pycnometer. The results showed that the characterization of FTIR and spectrophotometer UV for AMP exhibited forming amino propyl group at 3374.52 cm-1 with ?max 230 nm due to N–H bond; and the average of density of AMP resin sample was 1.7158 g/mL.

Glycerol conversion towards valuable fuel blending compounds with the assistance of SO3H-functionalized carbon xerogels and spheres

The SO3H-functionalized carbon xerogels and carbon spheres were obtained via modification of the initial materials with sulfuric acid or in situ generated diazonium salt (4‑benzenediazonium sulfonate). The catalytic activity of the prepared samples was evaluated in glycerol acetylation leading to valuable fuel blending compounds. The process was conducted at 80 °C, at a glycerol/acetic acid molar ratio of 1:6. The catalysts tested in the reaction were characterized by texture and elemental analysis, potentiometric titration, FTIR measurement, and also using SEM. The catalytic data obtained demonstrate that oxygenated fuel additives can be produced with a combined selectivity of 75% to diacetin and triacetin (DA and TA, respectively), and a selectivity of 25% to monoacetin (MA), with the glycerol conversion of about 97%. These results are comparable to those obtained for a commercial ion exchange resin (Amberlyst 15), indicating a great potential of modified carbons in the glycerol esterification process and other acid-catalyzed reactions.

Ionic Exchange Resins and Hydrogels for Capturing Metal Ions in Selected Sweet Dessert Wines.

Samples of sweet and dessert wines, Vin Santo (VSR) from Malvasia grapes, and Granello (GR) from Sauvignon grapes were collected and analyzed for the content of selected macro- and micro-nutrients (Na, K, Mg, Ca, Mn, Fe, Cu and Zn) and of Pb. GR wines had low levels for Fe, Cu and Zn, when compared to VSR and in particular Zn was two orders of magnitude lower. Methods to decrease the content of Zn and Cu in VSR, as well as those for reducing, at the same time, the concentrations of Ca, Mg and K in both VSR and GR, to avoid the formation of opalescence and depots of metal tartrates, were studied. Synthetic hydrogels containing l-histidine residue were tested. The overall relative lowering effects were by ca 4, 23, and 12% for K, Mg and Ca contents, and ca 6, 27 and 10%, for Mn, Cu and Zn contents, in GR wine samples. Commercial ion exchange resin Lanxess Lewatit L-207 and L-208 were then assayed, being legally allowed in the agro-food industry. The L-207 resin revealed great lowering effects on the concentrations of Mn, Cu and Zn, being 75, 91 and 97%, respectively, in VSR wines and 77, 76 and 92%, respectively, in GR wines. The content of Zn was reduced from 49.3 ± 1.2 mg/L in the original wine, down to 1.1 ± 0.1 mg/L, within 48 h soaking. The effects on the character of the dessert wines by the resin L-207 was also taken under control, measuring pH and color index. The color index changed by ca 15% and pH by ca 6% upon treatment of VSR wine with L-207 resins (48 h).

Selective Extraction of Rare Earth Elements from Phosphoric Acid by Ion Exchange Resins

Rare earth elements (REE) are present at low concentrations (hundreds of ppm) in phosphoric acid solutions produced by the leaching of phosphate ores by sulfuric acid. The strongly acidic and complexing nature of this medium, as well as the presence of metallic impurities (including iron and uranium), require the development of a particularly cost effective process for the selective recovery of REE. Compared to the classical but costly solvent extraction, liquid-solid extraction using commercial chelating ion exchange resins could be an interesting alternative. Among the different resins tested in this paper (Tulsion CH-93, Purolite S940, Amberlite IRC-747, Lewatit TP-260, Lewatit VP OC 1026, Monophos, Diphonix,) the aminophosphonic IRC-747, and aminomethylphosphonic TP-260 are the most promising. Both of them present similar performances in terms of maximum sorption capacity estimated to be 1.8 meq/g dry resin and in adsorption kinetics, which appears to be best explained by a moving boundary model controlled by particle diffusion.

The effect of contaminants on the application of polyamine functionalised ion exchange resins for uranium extraction from sulfate based mining process waters

Three in-house produced polyamine functionalised ion exchange resins and Purolite S985 (a commercial ion exchange resin) have been assessed for their ability to extract UO22+ from a variety of aqueous matrices applicable to current and potential future uranium mining processes. The uptake of common contaminant species in uranium processing liquors at variable acid concentrations has been assessed, with Al3+ and MoO42− showing the most extraction, with AsO43−, Eu3+ and Fe3+ showing extractions >10% at low [H+]. Extraction of MoO42−, AsO43−, Eu3+ and Fe3+ was seen to decrease with increasing [H+]. The impact of increasing [Cl−] on UO22+ and Fe3+ extraction has been determined. Fe3+ showed low extractions by all resins, with no dependence on [Cl−]. In contrast, increasing suppression of UO22+ uptake was seen with increasing [Cl−] up to 80 g L−1, with extraction remaining constant beyond this [Cl−]. At high [Cl−] (>50 g L−1) Purolite S985 was seen to remove UO22+ from solution more effectively than all synthesised polyamine resins. The presence of Fe3+ in solution was seen to suppress UO22+ uptake by around 10% when [Fe3+]/[UO22+] increased from 0 to 2. Fe3+ extraction by all studied resins was promoted by the presence of UO22+ in solution. This was most prevalent with Purolite S985, with an extraction of 30% for [Fe3+]/[UO22+] = 2 by Purolite S985. All resins were tested using a process water from a uranium mine and have shown an ability to selectively extract UO22+ from such solutions, with the best synthetic resin recovering 15.7% more uranium than Purolite S985.

Production of Biodiesel and Triacetin by Interesterification of Rapeseed Oil

Interesterification of vegetable oils is one of the methods which have been considered for biodiesel production. Average yield of fatty acid methyl esters (FAME)/triacetin (TA) containing product mixture obtained under developed optimal rapeseed oil (RO) interesterification reaction conditions reached 117.2%. Treatment of FAME/TA mixture with three different commercial ion exchange resins (Amberlyst-A26 (OH-), Amberlyst-15 (H+), Lewatit GF 202 (Na+)) and water was investigated to improve fuel properties or extract FAME and TA as two separate marketable products. Fuel properties of obtained product mixtures were relatively close to biodiesel obtained from RO by transesterification reaction with methanol. The highest influence on chemical composition of product mixture showed water as treatment agent. Water can be successfully used as extraction agent for separation of TA and other glycerol (G) acetates from fatty acid moiety containing compounds. Two separate product mixtures were obtained after treatment of FAME/TA containing mixture with water. G (~5 wt.%), DAG (~33 wt%) and TA (~61 wt.%) mixture extracted with water using developed method has high potential for application in different industrial areas. Rest of product mixture with high content of FAME (~77 wt.%) could be used as renewable fuel for diesel engine exploitation.

Adsorption behavior of cadmium ions from aqueous solution using pen shells

Pen shells which have some functional groups like amide, amino and carboxyl groups were used as an adsorbent to remove cadmium ions from an aqueous solution. The functional groups in pen shells were investigated by FT-IR and the surface condition of pen shells and existence of cadmium ions onto the pen shells were confirmed by the SEM and EDX analyses. The highest adsorption capacity could be achieved as about 35.652mg/g at the initial pH 4 of aqueous solution. Two adsorption isotherm models namely, Langmuir and Freundlich were used to fit the equilibrium data and the experimental data well follows the Langmuir isotherm model (r2=0.992) and the maximum adsorption capacity (qm) for cadmium ions was achieved as the 37.630mg/g by the Langmuir model. Also, adsorption kinetics for cadmium on the pen shells followed pseudo second order rate equation with 0.999 of correlation coefficient and the calculated qe value (35.594mg/g) was in excellent agreement with the experimental qe value (37.630mg/g). Changing of temperature of the aqueous solution could not greatly affect during the adsorption process between cadmium ions and pen shells. Also, pen shells had a high selectivity to the cadmium ions In addition, the desorption efficiency of cadmium ions was about 98.0% at the 0.5M of HCl and adsorption capacity of cadmium ions for reused pen shells can be still maintained at 31.65mg/g level until the 2nd cycle. From the result, adsorption process using pen shells could be applied to the removal system of cadmium ions from aqueous solution and it was suggested that conventional treatment process using commercial ion-exchange resin can be sufficiently replaced with economical process using waste pen shells with comparative high adsorption capacity.

Onsite defluoridation system for drinking water treatment using calcium carbonate

Fluoride in drinking water has several effects on teeth and bones. At concentrations of 1–1.5 mg/L, fluoride can strengthen enamel, improving dental health, but at concentrations above 1.5 to 4 mg/L can cause dental fluorosis. At concentrations of 4–10 mg/L, skeletal fluorosis can occur. There are many areas of the world that have excessive fluoride in drinking water, such as China, India, Sri Lanka, and the Rift Valley countries in Africa. Treatment solutions are needed, especially in poor areas where drinking water treatment plants are not available. On-site or individual treatment alternatives can be attractive if constructed from common materials and if simple enough to be constructed and maintained by users. Advanced on-site methods, such as under sink reserve osmosis units, can remove fluoride but are too expensive for developing areas. This paper investigates calcium carbonate as a cost effective sorbent for an onsite defluoridation drinking water system. Batch and column experiments were performed to characterize F− removal properties. Fluoride sorption was described by a Freundlich isotherm model, and it was found that the equilibrium time was approximately 3 h. Calcium carbonate was found to have comparable F− removal abilities as the commercial ion exchange resins and possessed higher removal effectiveness compared to calcium containing eggshells and seashells. It was also found that the anion Cl- did not compete with F− at typical drinking water concentrations, having little impact on the effectiveness of the treatment system. A fluoride removal system is proposed that can be used at home and can be maintained by users. Through this work, we can be a step closer to bringing safe drinking water to those that do not have access to it.

Sulfonated poly(divinylbenzene) and poly(styrene-divinylbenzene) as catalysts for esterification of fatty acids

Commercial ion-exchange resins (Amberlyst 35 and Amberlyst 36) and a resin synthetized in the laboratory, sulfonated poly(divinylbenzene) were evaluated as catalysts in the esterification of fatty acids (palmitic and oleic) with alcohols (methanol, ethanol and butanol). The study was developed in order to obtain a high rate of fatty acid conversion. The esterification reactions with fatty acids and methanol presented satisfactory conversion to methyl esters achieving a final conversion over 90% in both palmitic and oleic acid. A sample of waste vegetable oils with a high acid content from the residue of the palm oil and soybean oil refining industry were evaluated in the esterification with methanol. The best results were achieved with the new sulfonic resin, poly(divinylbenzene), which was synthesized in the laboratory and has proved efficient for the reaction in the study. Maximum biodiesel production was achieved from a fatty acid residue of the soybean oil refining industry and methanol (93%) which showed conversions very close to those obtained from their respective fatty acids.

Fabrication of Stable and Regenerable Amine Functionalized Magnetic Nanoparticles as a Potential Material for Pt(IV) Recovery from Acidic Solutions

MnFe2O4@SiO2-NH2 magnetic nanocomposite (AFMNC) adsorbent with a particle size of ∼50 nm was successfully synthesized using a facile approach. The as-prepared composite particles showed a fast binding of Pt(IV) with easy magnetic solid-liquid separation. The kinetic data were fitted to both pseudo-first and second-order rate models, indicating that AFMNC exhibited a much higher rate of Pt(IV) binding (0.125 g mg-1 min-1) compared to that of commercial ion-exchange resin Amberjet 4200 (0.0002 g mg-1 min-1). The equilibrium adsorption data were fitted to the Langmuir isotherm model with a relatively high sorption capacity of 380 mg/g. Scanning transmission electron microscopy analysis demonstrated the presence of platinum chloride after sorption on AFMNC, suggesting an adsorbate-adsorbent anion-exchange interaction. In addition, due to its magnetic characteristics, AFMNC can be easily separated from the aqueous medium after the sorption process. The novel nanocomposite may facilitate recovery of Pt(IV) from waste solutions.

Simultaneous etherification of isobutene with ethanol and 1-butanol over ion-exchange resins

The simultaneous liquid-phase etherification of isobutene with ethanol and 1-butanol to give ethyl tert-butyl ether (ETBE) and butyl tert-butyl ether (BTBE) has been studied, at temperatures in the range of 315–353K and at 2.5MPa, over six commercial acidic macroreticular ion-exchange resins as catalysts. The initial alcohol to isobutene molar ratio was varied in the range of 0.5–5.5 and the initial ethanol to 1-butanol molar ratio in the range of 0.5–2.0. Strongly acidic catalysts with a rigid polymer backbone structure enhance reaction rate. This fact, along with the reduced side reactions extent, makes Amberlyst™ 35 the most promising catalyst, among the tested ones, for the studied simultaneous etherification process. Irrespectively of the used catalyst, initial ETBE synthesis reaction rate is hardly sensitive to the variation of the ethanol to 1‐butanol molar ratio, whereas initial BTBE synthesis reaction rate strongly diminishes at high ethanol concentration. Preferential adsorption of ethanol over 1‐butanol on the catalysts active sites has been detected. As expected, both etherification reaction rates increase at increasing isobutene concentration. At 353K, the highest temperature, both etherification rates are affected by internal mass transfer resistances due to diffusion limitations even when small catalyst beads are used. The simultaneous process has been compared to the individual syntheses of ETBE and BTBE and it has been found that the isobutene selectivity towards ethers is enhanced in the simultaneous system.

Adsorption of Pb2+ ions from aqueous solutions by gelatin/activated carbon composite bead form

Gelatin and activated carbon materials have been combined together to obtain a gelatin/activated carbon composite bead form which is ecofriendly, nontoxic, biocompatible, and inexpensive material. In this paper, gelatin/activated carbon adsorption for Pb2+ ions from aqueous solutions was studied experimentally under various conditions. The experimental conditions such as contact time, solution pH, and gelatin/activated carbon dosage were examined and evaluated by using batch adsorption experiments. The maximum adsorption capacity of gelatin/activated carbon for Pb2+ ions was obtained to be 370.37 mg g−1. This maximum capacity was comparable with that of commercial ion exchange resins and it was much higher than those of natural zeolites. The uptake process for Pb2+ ions was found to be relatively fast with 92.15% of the adsorption completed in about 5 min in batch conditions. The adsorption capacity was also strongly solution pH dependent. Adsorption was observed at pH value as low as 2.0 and maximum adsorption was achieved at a pH of approximately 5. The results indicated that the gelatin/activated carbon was effective to be used as an adsorbent for Pb2+ ions removal in wastewater treatment.

Development of polyethyleneimine-loaded core-shell chitosan hollow beads and their application for platinum recovery in sequential metal scavenging fill-and-draw process

Polyethyleneimine (PEI)-loaded chitosan hollow beads (CHBs) were fabricated through the ionotropic gelation process using sodium tripolyphosphate (TPP) as a counter polyanion. The CHBs were loaded with hydrophilic PEI in pre- and/or post-loading methods. Hence, the sorbent could possess a large number of amine groups which were able to function as the binding sites to recover platinum metal ions. The enhancement of the amine groups was confirmed by Fourier transform infrared spectroscopy (FTIR). Isotherm and kinetic studies were carried out to evaluate the sorption performance of the sorbents. The maximum Pt(IV) uptake by the PEI-loaded CHBs was estimated to be 815.2±72.6mg/g, which was much higher than that of a commercial ion exchange resin, Lewatit® MonoPlus TP214 (330.2±16.6mg/g). A sequential metal scavenging fill-and-draw process was operated using the PEI-loaded CHBs sorbents for ten cycles and the Pt(IV) recovery efficiency was kept above 97.4% even after the last cycle. These results indicated that the ionic polymer-loaded hydrogel hollow beads can be a novel platform to design high-performance sorbents able to recover and/or scavenge anionic precious metal ions even from trace metal solutions.

Ammonium persulfate oxidized activated carbon fiber as a high capacity adsorbent for aqueous Pb(II)

An activated carbon fiber was oxidized with ammonium persulfate solutions (APS) and used for the adsorption of Pb(II) from aqueous solutions. A comprehensive study on the effect of the oxidation process conditions—oxidant concentration, oxidation temperature and time—on the obtained fibers Pb(II) adsorption capacity and their chemical and physical properties was done. Samples were characterized by elemental analysis, Boehm titration, N2 adsorption–desorption isotherms and infrared spectroscopy. Adsorption isotherms were obtained for the activated carbon fibers and for two commercial ion-exchange resins, and they showed good agreement with the Langmuir model. For the first time, an activated carbon fiber with a high adsorption capacity for aqueous Pb(II) was obtained (2.70mmolg−1, ca. 559mgg−1). This value was more than 10 times higher than that of the pristine fiber and superior to those of the commercial ion-exchange resins. The adsorption kinetics data of the oxidized activated carbon fiber were studied by different kinetic models and found to be better described by the pseudo-second order model, while the adsorption equilibrium could be reached in less than 2h. It was confirmed that the adsorption process mainly occurred by an ion-exchange mechanism. The obtained results showed that APS oxidation is capable of producing activated carbon fibers with high adsorption capacities for aqueous Pb(II), making them promising materials for industrial wastewater treatment applications.

Esterification of free fatty acids in non- edible oils using partially sulfonated polystyrene for biodiesel feedstock

Partially sulfonated polystyrene (PSS), synthesized from expanded polystyrene waste (EPS), was used as a catalyst for free fatty acid (FFA) conversion in non-edible oils. Acidic and water absorbing properties of the PSS facilitated the catalytic action for the FFA conversion by esterification reaction. The reaction was done on simulated acid oil (WCO) containing oleic acid and sunflower oil, and rubber seed oil (RSO). Effects of temperature, catalyst amount and alcohol to acid molar ratio were studied. FFA conversion increased with each of these factors. The advantage of this heterogeneous catalyst is that it is efficient as commercial ion exchange resin and easily removable from the reaction mixture. PSS is found to substantially reduce the acid value of WCO and RSO from 17 to 3.2mg KOH/g and from 28.8 to 4.8mg KOH/g respectively at 75°C. The WCO and RSO with reduced acid value may be used as a feedstock for biodiesel production.

Valorization of an Electronic Waste-Derived Aluminosilicate: Surface Functionalization and Porous Structure Tuning

This study involves the sustainable development of an ion exchange material with ultrahigh heavy metal uptake capacity from a waste material, originally destined for landfills. In this study, a promising thermo-alkaline reaction has been employed to simultaneously alter the surface chemistry and tune the textural properties of the waste-derived aluminosilicate. The effects of several reaction variables on the formation of mesotunnels in the structure of the material have been examined. Also, the surface characterization of the functionalized aluminosilicate has demonstrated that the functionalization reaction results in the cleavage of the robust T–O–T′ linkages (where T and T′ = Si or Al) into T–O– moieties, counterbalanced by an alkali metal cation, resulting in the coverage of the aluminosilicate surface with active ion exchange sites. Comparison of the ion exchange capacity of the functionalized aluminosilicate with those of the commercial ion exchange resins has proven exceptionally higher heavy metal uptake for the former. The ultrahigh heavy metal uptake of this material is ascribed to the high concentration of developed counterbalancing cations on the material surface. The attractiveness of this innovative approach is manifested by the dual environmental benefit, i.e., sustainable upcycling of a waste formerly deposited in landfills and its utilization for heavy metal-laden wastewater treatment.

Application of carbon foam for heavy metal removal from industrial plating wastewater and toxicity evaluation of the adsorbent

Electroplating wastewater contains various types of toxic substances, such as heavy metals, solvents, and cleaning agents. Carbon foam was used as an adsorbent for the removal of heavy metals from real industrial plating wastewater. Its sorption capacity was compared with those of a commercial ion-exchange resin (BC258) and a heavy metal adsorbent (CupriSorb™) in a batch system. The experimental carbon foam has a considerably higher sorption capacity for Cr and Cu than commercial adsorbents for acid/alkali wastewater and cyanide wastewater. Additionally, cytotoxicity test showed that the newly developed adsorbent has low cytotoxic effects on three kinds of human cells. In a pilot plant, the carbon foam had higher sorption capacity for Cr (73.64 g kg−1) than for Cu (14.86 g kg−1) and Ni (7.74 g kg−1) during 350 h of operation time. Oxidation pretreatments using UV/hydrogen peroxide enhance heavy metal removal from plating wastewater containing cyanide compounds.