Strong Base Anion Exchange Resin Research Articles

Sorption purification of sodium molybdate solutions to remove vanadium(V) impurity

Possibility of performing deep purification of concentrated sodium molybdate solutions to remove vanadium(V) impurity by selective sorption of vanadium(V) from the solutions with fixed pH values on a strong base anion exchange resin Purolite A500/2788 was demonstrated.

Enhancement of UV/H2O2 Efficacy Using Strong Base Anion Exchange Resins

Four surface drinking water sources were selected to investigate the impact of strong base anion (SBA) exchange resins—as a pretreatment to ultraviolet/hydrogen peroxide (UV/H2O2)—on dissolved organic carbon (DOC), nitrate, UV transmittance, and hydroxyl radical (·OH) scavenging of the water samples. Results demonstrated good efficiency of SBA exchange resins at increasing UV transmittance (up to 75%) and reducing DOC (up to 80%), nitrate (up to 75%), and sulfate (up to 75%) within the ion exchange (IX) conditions applied. Additionally, data confirmed the positive effect of IX treatment at reducing the ·OH scavenging characteristics of the water, especially for high‐DOC/low‐transmittance water sources. Electrical energy per order for removing a probe compound (4‐chlorobenzoic acid) was reduced 20 to 40%, indicating improvement in the efficacy of UV/H2O2 treatment. Study findings demonstrated the potential of using the IX process to improve the quality of water undergoing UV/H2O2 treatment and its subsequent benefits on UV/H2O2 efficacy and electrical energy consumption.

Equilibrium Studies on Phenol Removal from Industrial Wastewater Through Polymeric Resins

The efficient removal of phenol from industrial wastewaters has increasingly become a significant environmental concern due to its high toxicity even at low concentrations. In this research work, phenol removal from aqueous solution was evaluated by using Amberlyst A26, a strong-base anion exchange resin, and Amberlite IRA-67, a weak-base anion exchange resin. The influence of phenol concentration in the feedstream was investigated as well as the effect of recirculation time. In addition, equilibrium data fitted to theLangmuir, Freundlich and Temkin isotherms showed that the best correlation is given by Langmuir isotherm for both resins (R2 = 0.99). Experimental results revealed that phenol uptake is a spontaneous process for Amberlyst A26 (?G° = -1.55 kJ mol-1), whereas it is not spontaneous for Amberlite IRA-67 (?G° = 3.06 kJ mol- 1). Finally, Amberlyst A26 was confirmed to be considerably more efficient than Amberlite IRA-67 for thepotential removal of phenol from industrial effluents.

Dowex 1X4 and Dowex 1X8 as substitute of Diaion MA03SS in simulated moving bed chromatographic separation of sulfuric acid and sugars in concentrated sulfuric acid hydrolysates of bamboo

Abstract To find commercially available ion exchange resins comparable to a strong-base anion exchange resin Diaion MA03SS, which is specialized for the separation of sulfuric acid and sugars in concentrated sulfuric acid hydrolysates of non-food biomass by means of a simulated moving bed (SMB) chromatography, the screening test of 6 kinds of commercially available resins containing quaternary ammonium groups was carried out by a batch column-mode chromatographic separation of glucose and sulfuric acid at 50 °C. Based on results of the screening test, Dowex 1X4 and Dowex 1X8 were selected as replacements of Diaion MA03SS. The following SMB study using Diaion MA03SS, Dowex 1X4 and Dowex 1X8 at 50 °C clarified that Dowex 1X8 showed performances almost the same as those of Diaion MA03SS in the separations of sulfuric acid and sugars (mainly glucose and xylose) in hydrolysates of bamboo with 27 wt% sulfuric acid under the averaged flow rate of feed loading from 0.136 to 0.273 L/(h L-resin). For Dowex 1X8, recoveries of sulfuric acid were 90.5–93.4% and recoveries of glucose and xylose were 94.9–99.7% and 82.8–88.3%, respectively. Dowex 1X4 showed slightly higher recoveries for three solutes; namely sulfuric acid recoveries were 95.0–95.5% and glucose and xylose recoveries were 100–101% and 86.1–91.7%, respectively. However, the highest averaged flow rate of feed loading for Dowex 1X4 was 0.205 L/(h L-resin) because of the higher column pressure loss owing to its high shrinking in 30 wt% sulfuric acid. Thus, it became clear that Dowex 1X8 exhibit excellent performances comparable to or higher than those of Diaion MA03SS in the SMB chromatographic separation of sulfuric acid and sugars in concentrated sulfuric acid hydrolysate of bamboo.

Evaluation of Weak and Strong Basic Anion Exchange Resins for NOM Removal

The feasibility of using ion exchange resins in stirred (suspended) mode operation for the removal of natural organic matter (NOM) from surface water was investigated. Resins were compared in terms of their NOM removal capacity, kinetics, and regeneration efficiency under batch and consecutive batch loading conditions. The dominant mechanism for NOM removal with the strong basic A860 resin was ion exchange whereas a combination of ion exchange and surface adsorption governed the removal with the weak basic A847. The estimated limiting capacity (qm) and the equilibrium constant (α) for A860 were higher than the ones for A847, showing greater affinity of A860 for natural organic matter. Also, under consecutive batch loadings, the strong basic resin showed greater removal (∼10% higher) compared to A847. Different regeneration scenarios were also examined and A860 resin showed a superior regeneration efficiency (∼20%) compared to A847. Overall, findings indicated the strong basic resin as a better candidate for the removal of NOM from surface water. This paper proposes an evaluation scheme for the selection of appropriate ion exchange resins aiming to reduce NOM in surface waters.

Pilot Testing Strong Base Anion Exchange for CrVI Removal

California, the first state in the nation to regulate hexavalent chromium (CrVI) in drinking water, has set a maximum contaminant level (MCL) of 10 µg/L. To comply with the MCL, a California utility conducted extensive pilot studies to determine the best‐performing ion exchange resin, empty bed contact time (EBCT), and hydraulic loading rate (HLR). The CrVI removal capacities of four strong base anion exchange resins were tested at seven wells. Results showed that between 12,000 and 37,000 bed volumes of treatment can be expected before an 8‐µg/L breakthrough threshold. HLR was shown to have little effect on CrVI removal within the range tested (7.5 to 30 gpm/ft2), whereas longer EBCTs (>45 s) appeared to improve performance. The presence of co‐occurring anions in the raw water—namely, sulfate and nitrate—had substantial effect on the resin's chromium loading capacity.

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.

Integrated adsorptive technique for efficient recovery of m-cresol and m-toluidine from actual acidic and salty wastewater

An integrated adsorptive technique combining an m-cresol adsorption unit, an acid retardation unit and an m-toluidine adsorption unit in sequence was designed to recover m-cresol and m-toluidine from highly acidic and salty m-cresol manufacturing wastewater. In the first column packed with hypercrosslinked polymeric resin (NDA-99), most m-cresol was captured through π-π and hydrogen-bonding interactions as well as the salting-out effect, while m-toluidine was not absorbed due to protonation. To separate acid from salt, an acid retardation unit was introduced successively to adsorb sulfuric acid by strong base anion exchange resin (201×7). After the acid retardation unit and mild neutralization reaction, the last column filled with NDA-99 was applied to trap neutral m-toluidine from the salty effluent. Moreover, the eluent of the acid retardation unit was utilized as the regenerant to recover m-toluidine, and the recycled high-acidity and low-salinity solution of m-toluidine was directly used to produce m-cresol as the raw material. Therefore, the proposed method not only efficiently recycled m-cresol and m-toluidine, but also reduced the consumption of alkali dramatically (saving 0.1628t/t wastewater). These findings will inspire design of integrated adsorptive techniques for treating complex organic wastewater with high efficiency and low cost.

Selectivity of bicarbonate-form anion exchange for drinking water contaminants: Influence of resin properties

Abstract Bicarbonate was investigated as a new counterion for six strong-base anion exchange resins considering the selective removal of six drinking water contaminants: nitrate, bromide, perchlorate, sulfate, chromate, and Suwannee River natural organic matter (SRNOM). The most selective bicarbonate-form resin for each contaminant was evaluated based on qualitative binary ion exchange plots and quantitative separation factor calculation. The influence of resin properties and ion characteristics was evaluated on resin selectivity for each contaminant. The type of functional group and polymer composition of the resin were shown to influence selectivity for inorganic contaminants, and the pore structure and polymer composition of resin were shown to influence selectivity for SRNOM. Bicarbonate-form resin with wide spacing of functional groups (i.e., triethylamine) and polystyrene composition was favorable for monovalent, hydrophobic contaminants, including nitrate, bromide, and perchlorate, whereas resin with close spacing of functional groups (i.e., trimethylamine) and polystyrene composition was favorable for relatively hydrophobic chromate and resin with same functional group and polyacrylic composition was favorable for relatively hydrophilic sulfate ion. For organic contaminant, bicarbonate-form resin with macroporous structure and polyacrylic composition was most selective for SRNOM. In addition, the resin selectivity sequence for each contaminant based on separation factor calculations was compared with adsorption isotherm parameters, and the similarities and differences are discussed. The separation factor method is based on ion exchange stoichiometry, whereas adsorption method is robust in terms of simplifying calculation.

Performance and modeling of continuous ion exchange processes for phenols recovery from olive mill wastewater

A continuous-flow ion exchange (IE) process for phenols recovery from olive mill wastewaters was examined through both strong-base and weak-base anion exchange resins. The effect of initial pH showed that phenols removal efficiency increased with an increase in the pH value up 7 and efficiency remains constant at higher pH values for Amberlyst A26. On the other hand, phenols removal efficiency for Amberlite IRA-67 also increased with an increase in the pH value up 7, reaching phenols removal efficiencies close to 57%. In addition, Thomas, Yoon–Nelson and Clark models were applied to the experimental data to predict the breakthrough curves. The simulation of the best-performing operational condition was used to evaluate the process performances for different inlet phenols concentrations (5, 25 and 100mgL−1). The results showed an increase in initial phenols concentration improved the adsorption capacity. In both cases, the Thomas model was found to give best fit to experiment data for the three initial phenols concentrations, followed by the Yoon–Nelson and Clark models. Finally, column regeneration studies showed almost 100% phenols recovery efficiencies were obtained. IE process led to a phenols solution susceptible to be concentrated and used in food, cosmetic or pharmaceutical sectors.

Non-ionic macroporous polystyrene adsorbents for removal of serum toxins in liver failure by hemoperfusion

Strong base anion exchange resin (e.g., BL-300) is currently used to eliminate bilirubin from blood in clinical hemoperfusion. However, there is a potential weakness of the resin to remove heparin and activation of coagulation. To overcome this weakness, we prepared a novel non-ionic macroporous polystyrene adsorbent (SZ-9) with rich mesopores and high surface area by suspension polymerization. Test results indicated that SZ-9 performed better adsorption capacity for bilirubin than BL-300. In addition, better blood compatibility was observed during whole blood hemoperfusion. Therefore, adsorbent SZ-9 might be an efficient alternative to anion exchange resin for the removal of bilirubin in hemoperfusion.

Phenols removal from industrial effluents through novel polymeric resins: Kinetics and equilibrium studies

Abstract The efficient removal of phenols from wastewaters has increasingly become a significant environmental concern due to its high toxicity even at low concentrations. In this research work, phenols removal from aqueous solution was evaluated by using Amberlyst A26, a strong-base anion exchange resin, and Amberlite IRA-67, a weak-base anion exchange resin. The influence of phenols concentration in the feedstream was investigated as well as the effect of recirculation time. Equilibrium data fitted to the Langmuir, Freundlich and Temkin isotherms revealed Langmuir isotherm provided the best correlation for both resins ( R 2 = 0.99). Kinetic studies performed based on pseudo-first order, pseudo-second order and intraparticle diffusion models showed that although the correlation coefficients of the second-order model were the highest ( R 2 = 1) and also the SSE values were the lowest ( G ° = −1.55 kJ mol −1 ), whereas it is not spontaneous for Amberlite IRA-67 (Δ G ° = 3.06 kJ mol −1 ). Finally, Amberlyst A26 was confirmed to be considerably more efficient than Amberlite IRA-67 for the potential removal of phenols from industrial effluents.

Sorptive recovery of rhodium (III) from multicomponent chloride solutions in presence of tin (II) chloride

The paper studies the effect of tin (II) chloride additive agents on the sorption of rhodium (III) on ion-exchange resin Purolite S920 with isothiouronium functional groups, weak base anion-exchange resin Purolite S985, and a strong-base anion-exchange resin Purolite A500. It is found that introduction of SnCl2 leads to a substantial improving of selectivity of all tested ion-exchange resins to Rh(III), and increases sorption rate on ion-exchange resins S985 and S920. The paper determines the optimum dosage of SnCl2 (0,01 mol/l), at which partition coefficients of Rh(III) during adsorption on all tested ion-exchange resins reach maximum values. It is shown that quantitative recovery of Rh(III) is achieved in practice during flowing of the multicomponent chloride solution composed of, g/l: 0,2 Rh(III); 72,9 HCl; 53,5 NH4Cl; 2,7 Al(III); 1,23 Fe(III); 5,9 Sn(IV) with addition of SnCl2, through the ion-exchange resin Purolite S920 with isothiouronium functional groups. Desorption of Rh(III) from the saturated ion-exchange resin Purolite S920 with the use of an acidified thiourea solution is not full, no more than 60 %.

Comparison between different ion exchange resins combinations for final treatment of olive mill effluent

Abstract Industrial wastewater is subjected to strict environmental legislation, thus making its adequate management a key issue. In this research work, the final purification of two-phase olive mill wastewater (OMW-2) was investigated through four ion exchange resins (a weak-acid cation exchange resin, a strong-acid cation exchange resin, a weak-base anion exchange resin and a strong-base anion exchange resin). Central composite design was used for the optimization of the IE processes. Results revealed that the only final treated OMW-2ST effluent fulfilling the legislated requirements for drinking water was the one from the combination of the strong-acid cation exchange resin and the weak-base anion exchange resin. The proposed IE process yielded up to 88% removal of these pollutants when the initial pH, operating temperature and flow rate were set to 5.1, 26.8 °C and 12.1 L h−1, respectively. Under these conditions, the achieved concentrations for all contaminants in the final stream were maintained below the maximum established limits. Finally, high treated effluent volume recovery (28 L) could be achieved in continuous mode under the optimal operating conditions found, complying with standards for reuse in the production process.

Regeneration of a perchlorate-exhausted highly selective ion exchange resin: Kinetics study of adsorption and desorption processes

Perchlorate is a stable and soluble ion that can last for decades in the environment and can cause a number of environmental and health issues. Perchlorate is commonly removed using highly-selective ion-exchange resins that are replaced after exhaustion and incinerated or disposed in a landfill since there is no viable regeneration method. The major limitations in regeneration of single use resins is achieving complete desorption of perchlorate. The sustainability of treatment processes for perchlorate contaminated water can be achieved by regenerating the exhausted resin. As the first step of resin bioregeneration study, research on the adsorption and desorption kinetics of the perchlorate ion from a strong base anion exchange resin was conducted. Different chemical reaction and diffusion models were analyzed using experimental data. Both adsorption and desorption experimental data were best described by the Pseudo-second order model with adsorption rate constants of 2 × 10−3 ± 0.001 (g/mg/min) and desorption rate constants of 5 × 10−2 ± 0.01 (g/mg/min). These results suggest that the rate limiting stage for adsorption and desorption of perchlorate ion into the resin can be chemisorption.

Removal of phosphorus by a high rate membrane adsorption hybrid system

Membrane adsorption hybrid system (MAHS) was evaluated for the removal of phosphate from a high rate membrane bioreactor (HR-MBR) effluent. The HR-MBR was operated at permeate flux of 30L/m2h. The results indicated that the HR-MBR could eliminate 93.1±1.5% of DOC while removing less than 53% phosphate (PO4-P). Due to low phosphate removal by HR-MBR, a post-treatment of strong base anion exchange resin (Dowex∗21K-XLT), and zirconium (IV) hydroxide were used as adsorbent in MAHS for further removal of phosphate from HR-MBR effluent. It was found that the MAHS enabled to eliminate more than 85% of PO4-P from HR-MBR effluent. Hence, HR-MBR followed by MAHS lead to simultaneous removal of organics and phosphate in a reliable manner. The experiments were conducted only for a short period to investigate the efficiency of these resins/adsorbents on the removal of phosphorus and high rate MBR for organic removal.

M-PGMA as a new water treatment agent to remove oxytetracycline from water

Magnetic ion exchange resin is a strong base anion exchange resin with magnetic properties that can be used to remove negatively charged materials from water. Magnetic poly glycidyl methacrylate resin (m-PGMA), a new type of resin, has shown better removal performance for humics than MIEX®. Removal of oxytetracycline (OTC) in water by m-PGMA, and factors influencing the removal, were examined, and in addition, the removal of OTC by MIEX and powdered activated carbon (PAC) were used as a comparison. Results showed that m-PGMA could remove more OTC than MIEX and PAC. The removal performance was greatly affected by dosage of m-PGMA, inorganic anions, organics and pH value. At a contact time of 30 min, the removal rates of OTC were 45%, 52% and 63% when the dosage was 5 ml/L, 10 ml/L and 20 ml/L, respectively. In comparison the removal rate of OTC by MIEX was 45% with a dosage of 10 mL/L and a contact time of 30 min. The removal of OTC was significantly increased when the pH value was above 7.3, as the OTC molecule exists as an anion in alkaline medium. In conclusion, m-PGMA is more effective than MIEX and PAC in the removal of OTC in water, and can be one of the choices to remove trace organics like OTC.

Optimization of polyphenol recovery from mango peel extracts by assessing food-grade adsorbent and ion exchange resins and adsorption parameters using a D-optimal design

Seven adsorbent and anion exchange resins with different polymeric backbones and functional groups were evaluated in the present study regarding their polyphenol adsorption efficiency. A food-grade strong basic anion exchange resin proved to be most suitable for gallic acid adsorption from a model solution, presumably due to its cross-linked polystyrene matrix and functional quaternary ammonium groups. Besides gallic acid, the nonionic mangiferin was efficiently adsorbed by this resin. Optimum conditions for gallic acid binding were identified by means of a D-optimal design at the independent process parameters of pH 7, temperature of 293 K, 50 mg/L gallic acid concentration, and 0.12 g DM resin per 100 mL gallic acid model solution. Optimum adsorption conditions were transferred from batch experiments to column adsorption experiments using a complex phenolic mango peel extract. Polyphenol binding from the crude peel extract was excellent as demonstrated by an exhaustive adsorption of ≥99.9 % of differently structured polyphenols. Moreover, the desorption, i.e., recovery rate, of polyphenols was studied using both acidic and alkaline eluents. Polyphenol adsorption by anion exchange resins may contribute to optimized adsorption processes, thus, being useful for the industrial exploitation of sensory acceptable mango byproducts.

Preparation of thiacalix[4]arenetetrasulfonate-modified D201 resin and its adsorption of heavy metal ions

A thiacalix[4]arenetetrasulfonate-modified resin has been prepared by loading thiacalix[4]arenetetrasulfonate onto resins for the adsorption of heavy metal ions. Various factors affecting the adsorption capacities such as different resins, resin size, pH, contact time, and temperature were investigated by batch adsorption experiments, and the adsorption isotherms, thermodynamics, kinetics, selectivity, and regeneration were also studied. It was found that the loading capacity of the D201 resin (macroporous strong basic anion exchange resin) for thiacalix[4]arenetetrasulfonate was substantially higher than those of the D301 (macroreticular weak basic styrene anion exchange resin) and the 717 (strong base styrene anion exchange resin) resins and increased with decreasing particle size of the D201 resin. The adsorption kinetics followed the pseudo-second-order rate law for heavy metal ions, indicating that chemical sorption is the rate-limiting step of the adsorption mechanism. The adsorption of heavy metal ions onto the thiacalix[4]arenetetrasulfonate-modified resin was analyzed and was found to fit better to the Langmuir isotherm than to the Freundlich isotherm, and the maximum adsorption capacities were 78.1, 65.8, 54.3, and 49.8 mg/g for Cu2+, Zn2+, Cd2+, and Pb2+ ions, respectively. The prepared modified resin has high adsorption selectivity for heavy metal ions under the co-occurrence of alkali metal and alkaline earth metal ions. The regeneration efficiencies still exceed 90% after five cycles, indicating that the thiacalix[4]arenetetrasulfonate-modified resin could be favorably recycled.

음이온교환수지를 이용한 CO2흡수 공정시 발생하는 열안정성염 처리 특성

In this study, we studied the characteristics of ion exchange for treatment of HSS (heat stable salts) which cause performance reduction in CO2 gas capture amine solution using anion exchange resins. The optimum HSS removal efficiency, 96.1% was obtained when using strong base anion exchange resin SAR10 at dosage 0.05 g/mL, 316 K, pH 12 and the best resin regeneration efficiency, 78.8% was obtained using NaOH solution of 3 M at 316 K. The adsorption data were described well by the Freundlich model and the sorption intensity(n) was 2.0951 lying within the range of favorable adsorption. The adsorption selectivity coefficients were increased by increasing valences and size of ion and desorption selectivity coefficients showed a contradictory tendency to adsorption selectivity coefficients. By continuous HSS removal experiments, 13.3 BV of HSS con- taminated solution was effectively treated and the optimum NaOH solution consumption was 5.2 BV to regenerate resins.