Iron element is one of the main impurities in wet-process phosphoric acid and it has a significant impact on the subsequent phosphorus chemical products. This paper studied the feasibility of using Sinco-430 cation ex...Iron element is one of the main impurities in wet-process phosphoric acid and it has a significant impact on the subsequent phosphorus chemical products. This paper studied the feasibility of using Sinco-430 cation exchange resin for iron removal from phosphoric acid. The specific surface area and the total exchange capacity of resin were 8.91 m2·g-1 and 5.18 mmol·g-1, respectively. The sorption mechanism was determined by FTIR and XPS and the results indicated that iron was combined with-SO3 H in resin. The removal process was studied as a function of temperature, H3 PO4 content and mass ratio between resin and solution. The unit mass of resin to remove iron was 0.058 g·g-1 resin when the operating parameters were T = 50 ℃, H3 PO4 content = 27.61 wt%and S/L = 0.1, respectively. Kinetics study demonstrated that pseudo-second-order reaction model fits this study best and the calculated activation energy of overall reaction is 29.10 kJ·mol-1. The overall reaction process was mainly controlled by pore diffusion.展开更多
The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influenc...The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influences of experimental parameters such as pH, temperature, initial concentration and adsorption rate were investigated. The experimental results show that in the studied concentration range, 001×7 resin has a good sorption ability for Cd2+, and the equilibrium adsorption data fit to Freundlich isotherms. The adsorption is an exothermic process which runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best adsorption condition is pH 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the desorption efficiency is over 98%. The maximal static saturated adsorption capacity is 355 mg/g (wet resin) at 293 K. The adsorption mechanism of Cd2+ on 001×7 resin was discussed based on IR spectra.展开更多
In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxide...In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment.Characteristics of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray diffraction.The results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH 5.In addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.展开更多
Classic physical and chemical treatments applied to separating clay minerals from the host sediments are often difficult or aggressive for clay minerals. A technique using cation exchange resins (amberlite IRC\|50H an...Classic physical and chemical treatments applied to separating clay minerals from the host sediments are often difficult or aggressive for clay minerals. A technique using cation exchange resins (amberlite IRC\|50H and amberlite IR\|120) is used to separate clay minerals from the host sediments. The technique is based on the exchange of cations in the minerals that may be associated clay minerals in sediments, such as Ca and Mg from dolomite; Ca from calcite, gypsum and francolite with cations carried by resin radicals. The associated minerals such as gypsum, calcite, dolomite and francolite are removed in descending order. Separation of clay minerals using cation exchange resins is less aggressive than that by other classic treatments. The efficiency of amberlite IRC\|50H in the removal of associated minerals is greater than that of amberlite IR\|120.展开更多
This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins(SCER). The effects of the mass ratio of methanol to acidified ...This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins(SCER). The effects of the mass ratio of methanol to acidified oil,reaction temperature,and catalyst loading were studied to optimize the conditions for maximum conversion of free fatty acids(FFAs). The results showed that the optimal conversion rate of FFAs was 91.87% at the mass ratio of methanol to acidified oil of 2.5:1.0,reaction temperature of 65.0 °C,catalyst loading of 5.0 g and reaction time of 8.0 h. The external and internal mass transfer resistances were negligible based on the experimental results and a pseudo-homogeneous kinetic model was proposed for the esterification. The activation energy and thermodynamic parameters including G,S and H were determined. The conversion rates of FFAs obtained from the established model were in good agreement with the experimental data.展开更多
The polystyrene cation exchange resin was exchanged by La 3+ and then were carbonized to make resin carbon material. The electrochemical properties of the resin carbon material as the electrode of the lithium ion...The polystyrene cation exchange resin was exchanged by La 3+ and then were carbonized to make resin carbon material. The electrochemical properties of the resin carbon material as the electrode of the lithium ion cell were investigated. The test results show that comparing with the polystyrene cation exchange resin without adulterating, the contents of hydrogen, oxygen and sulfur are changed obviously for the resin carbon material derived from the La 3+ adulterating polystyrene cation exchange resin. The contents of hydrogen and oxygen are increased, and the one of sulfur is decreased. The test results also indicate that it is more easily to form the stratum graphite minicrystal structure with bigger diameter for the La 3+ adulterating resin. According to the electrochemical test results, the electrode derived from La 3+ adulterating polystyrene cation exchange resin has much better electrochemical property, and the capacity of charge and discharge of the electrode is increased about 30 mAh·g -1 in average.展开更多
The retention mechanism of monocarboxylic acids on a cation-exchange resin column was investigated. It was assumed that both Donnan membrane equilibrium and adsorption equilibrium were involved in the chromatographic ...The retention mechanism of monocarboxylic acids on a cation-exchange resin column was investigated. It was assumed that both Donnan membrane equilibrium and adsorption equilibrium were involved in the chromatographic process. On the basis of the proposed mechanism, an equation was derived for correlating distribution coefficient, Kd, dissociation constant, Aa, and adsorption equilibrium constant, K, of the analyzed acid. By this approach, retention data for some aliphatic acids under different operating conditions were predicted. Results are reasonably in agreement with experiment.展开更多
Strongly acidic cation exchange resin(1x1,H form)has been successfully used as a catalyst in synthesis of diphenyl N-benzyloxycarbonyl-1-aminobenzylphosphonate, N-benzyloxycarbonyl-1-aminobenzylphenylphosphinic acid a...Strongly acidic cation exchange resin(1x1,H form)has been successfully used as a catalyst in synthesis of diphenyl N-benzyloxycarbonyl-1-aminobenzylphosphonate, N-benzyloxycarbonyl-1-aminobenzylphenylphosphinic acid and N-p-tolylsulfonyl-1-aminobenzyl phenylphosphinic acid in high yields.展开更多
In this paper, it was investigated that the effect of parameters such as the ionic strength, pH, counter-ion type of release medium, particle size, and cross linkage of cation exchange resin on the release of model dr...In this paper, it was investigated that the effect of parameters such as the ionic strength, pH, counter-ion type of release medium, particle size, and cross linkage of cation exchange resin on the release of model drug pseudoephedrine hydrochloride (PE) from uncoated drug-resin complex. The drug-resin complex was prepared by the reaction of PE with strongly acidic cation exchange resin (001×4, 001×7, 001×14). The result showed that the loading of PE increased with the increase of temperatures. The release of PE from drug-resin complex at 37℃ was monitored in vitro. From the experiments, it was found that the release rate of PE depends on the pH, composition of the releasing media, increased at lower pH media or with increase of ionic strength of media. Moreover, the release rate of PE was inversely proportional to the cross-linkage and particle size of the cation exchange resin.展开更多
The treatment and disposal of radioactive waste are presently facing great challenges.Spent ion exchange resins have become a focus of attention due to their high production and serious environmental risks.In this pap...The treatment and disposal of radioactive waste are presently facing great challenges.Spent ion exchange resins have become a focus of attention due to their high production and serious environmental risks.In this paper,a simplified model of cationic exchange resin is proposed,and the degradation processes of cationic resin monomer initiated by hydroxyl radicals(·OH)are clarified by combining statistical molecular fragmentation(SMF)model and density functional theory(DFT)calculations.The prediction of active sites indicates that the S-O bonds and the C-S bond of the sulfonic group are more likely to react during the degradation.The meta-position of the sulfonic group on the benzene ring is the most active site,and the benzene ring without the sulfonic group has a certain reactivity.The C11-C14 and C17-C20 bonds,on the carbon skeleton,are the most easily broken.It is also found that dihydroxy addition and elimination reactions play a major role in the process of desulfonation,carbon skeleton cleavage and benzene ring separation.The decomposition mechanisms found through the combination of physical models and chemical calculations,provide theoretical guidance for the treatment of complex polycyclic aromatic hydrocarbons.展开更多
This study assessed the adsorption process and the reaction kinetics involved in the selective recovery of vanadium from an acid solution containing iron as an impurity.Four commercial resins were studied:Lewatit^(...This study assessed the adsorption process and the reaction kinetics involved in the selective recovery of vanadium from an acid solution containing iron as an impurity.Four commercial resins were studied:Lewatit^(®)MonoPlus TP 209 XL,Lewatit^(®) TP 207,Dowex^(TM)M4195(chelating resin)and Lewatit^(®) MonoPlus S 200 H(strong cationic exchange resin).To investigate the effect of time on the adsorption process,batch experiments were carried out using the following initial conditions:pH 2.0,298 K,and a proportion of 1 g of resin to 50 mL of solution.The variation of pH over time was analyzed.Chelating resin released less H+ions as the adsorption occurred,resulting in a lower drop of pH when compared to S 200 H resin.Ion adsorption by the resins was also evaluated through FT-IR and SEM−EDS before and after the experiments.Among the evaluated kinetic models(pseudo-first order,pseudo-second order,Elovich and intraparticle diffusion models),the pseudo-second order model best fits the experimental data of the adsorption of vanadium and iron by all of the four resins.M4195 resin showed the highest recovery of vanadium and the lowest adsorption of iron.Kinetic data,which are fundamental to industrial processes applications,are provided.展开更多
To develop a simple and rapid purification method of rohitukine from the stem bark of Dysoxylum binectariferum. A L9 (34) orthogonal test was designed to optimize the extraction condition. Rohitukine in the plant e...To develop a simple and rapid purification method of rohitukine from the stem bark of Dysoxylum binectariferum. A L9 (34) orthogonal test was designed to optimize the extraction condition. Rohitukine in the plant extract was purified by using solvent-solvent partition and cation exchange resion (CER). Five different types of packing materials, including XAD-2 resin, polyamide, Sephadex LH-20, ODS and CER, were compared and CER showed the best capacity for rohitukine separation. The purification procedure was optimized as follows: the plant material powder was extracted with 70% ethanol (v/m = 60) by ultrasonic agitation for 60 min, then the 70% ethanol extract was dissolved in aqueous solution (pH 1, adjusted with 0.5 mol/L HCl) and extracted with equal volume of n-butanol. The aqueous layer was retained and the pH was adjusted to 10 with 25% aqueous ammonia and a solventsolvent partition was performed with equal volume of n-butanol. The obtained n-butanol extract was dissolved in aqueous solution (pH 1, adjusted with 0.5 mol/L HCl), and purified by a CER column eluting with H2O and 70% ethanol (pH 10, adjusted with 25% aqueous ammonia), successively. Rohitukine existed in 70% ethanol eluate, with a purity up to 53.3%. The method developed in this study provides a simple and rapid approach for the preparation of rohitukine from the stem bark ofD. binectariferum.展开更多
基金Supported by the National Basic Research Program of China(2016YFD0200404)
文摘Iron element is one of the main impurities in wet-process phosphoric acid and it has a significant impact on the subsequent phosphorus chemical products. This paper studied the feasibility of using Sinco-430 cation exchange resin for iron removal from phosphoric acid. The specific surface area and the total exchange capacity of resin were 8.91 m2·g-1 and 5.18 mmol·g-1, respectively. The sorption mechanism was determined by FTIR and XPS and the results indicated that iron was combined with-SO3 H in resin. The removal process was studied as a function of temperature, H3 PO4 content and mass ratio between resin and solution. The unit mass of resin to remove iron was 0.058 g·g-1 resin when the operating parameters were T = 50 ℃, H3 PO4 content = 27.61 wt%and S/L = 0.1, respectively. Kinetics study demonstrated that pseudo-second-order reaction model fits this study best and the calculated activation energy of overall reaction is 29.10 kJ·mol-1. The overall reaction process was mainly controlled by pore diffusion.
基金Project(2005) supported by the Basic Technology Research Item of Explosive Industry, China
文摘The adsorption behavior of Cd2+ on 001×7 strong-acid cation exchange resin was studied with the static adsorption method. The adsorption process was analyzed from thermodynamics and kinetics aspects. The influences of experimental parameters such as pH, temperature, initial concentration and adsorption rate were investigated. The experimental results show that in the studied concentration range, 001×7 resin has a good sorption ability for Cd2+, and the equilibrium adsorption data fit to Freundlich isotherms. The adsorption is an exothermic process which runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best adsorption condition is pH 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the desorption efficiency is over 98%. The maximal static saturated adsorption capacity is 355 mg/g (wet resin) at 293 K. The adsorption mechanism of Cd2+ on 001×7 resin was discussed based on IR spectra.
基金Vietnam National University-Ho Chi Minh City under grant number A2020-16-01.
文摘In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal salts.The cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water environment.Characteristics of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray diffraction.The results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH 5.In addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.
文摘Classic physical and chemical treatments applied to separating clay minerals from the host sediments are often difficult or aggressive for clay minerals. A technique using cation exchange resins (amberlite IRC\|50H and amberlite IR\|120) is used to separate clay minerals from the host sediments. The technique is based on the exchange of cations in the minerals that may be associated clay minerals in sediments, such as Ca and Mg from dolomite; Ca from calcite, gypsum and francolite with cations carried by resin radicals. The associated minerals such as gypsum, calcite, dolomite and francolite are removed in descending order. Separation of clay minerals using cation exchange resins is less aggressive than that by other classic treatments. The efficiency of amberlite IRC\|50H in the removal of associated minerals is greater than that of amberlite IR\|120.
基金support from the Natural Science Foundation of Shandong Province (Grant no.ZR2013BL010)the Research Excellence Award of Shandong University of Technology and the Zibo Technology Research and Development Program of China (Grant no.2013GG04110)
文摘This study describes the kinetics and thermodynamics of the esterification of acidified oil with methanol catalyzed by sulfonated cation exchange resins(SCER). The effects of the mass ratio of methanol to acidified oil,reaction temperature,and catalyst loading were studied to optimize the conditions for maximum conversion of free fatty acids(FFAs). The results showed that the optimal conversion rate of FFAs was 91.87% at the mass ratio of methanol to acidified oil of 2.5:1.0,reaction temperature of 65.0 °C,catalyst loading of 5.0 g and reaction time of 8.0 h. The external and internal mass transfer resistances were negligible based on the experimental results and a pseudo-homogeneous kinetic model was proposed for the esterification. The activation energy and thermodynamic parameters including G,S and H were determined. The conversion rates of FFAs obtained from the established model were in good agreement with the experimental data.
文摘The polystyrene cation exchange resin was exchanged by La 3+ and then were carbonized to make resin carbon material. The electrochemical properties of the resin carbon material as the electrode of the lithium ion cell were investigated. The test results show that comparing with the polystyrene cation exchange resin without adulterating, the contents of hydrogen, oxygen and sulfur are changed obviously for the resin carbon material derived from the La 3+ adulterating polystyrene cation exchange resin. The contents of hydrogen and oxygen are increased, and the one of sulfur is decreased. The test results also indicate that it is more easily to form the stratum graphite minicrystal structure with bigger diameter for the La 3+ adulterating resin. According to the electrochemical test results, the electrode derived from La 3+ adulterating polystyrene cation exchange resin has much better electrochemical property, and the capacity of charge and discharge of the electrode is increased about 30 mAh·g -1 in average.
文摘The retention mechanism of monocarboxylic acids on a cation-exchange resin column was investigated. It was assumed that both Donnan membrane equilibrium and adsorption equilibrium were involved in the chromatographic process. On the basis of the proposed mechanism, an equation was derived for correlating distribution coefficient, Kd, dissociation constant, Aa, and adsorption equilibrium constant, K, of the analyzed acid. By this approach, retention data for some aliphatic acids under different operating conditions were predicted. Results are reasonably in agreement with experiment.
文摘Strongly acidic cation exchange resin(1x1,H form)has been successfully used as a catalyst in synthesis of diphenyl N-benzyloxycarbonyl-1-aminobenzylphosphonate, N-benzyloxycarbonyl-1-aminobenzylphenylphosphinic acid and N-p-tolylsulfonyl-1-aminobenzyl phenylphosphinic acid in high yields.
文摘In this paper, it was investigated that the effect of parameters such as the ionic strength, pH, counter-ion type of release medium, particle size, and cross linkage of cation exchange resin on the release of model drug pseudoephedrine hydrochloride (PE) from uncoated drug-resin complex. The drug-resin complex was prepared by the reaction of PE with strongly acidic cation exchange resin (001×4, 001×7, 001×14). The result showed that the loading of PE increased with the increase of temperatures. The release of PE from drug-resin complex at 37℃ was monitored in vitro. From the experiments, it was found that the release rate of PE depends on the pH, composition of the releasing media, increased at lower pH media or with increase of ionic strength of media. Moreover, the release rate of PE was inversely proportional to the cross-linkage and particle size of the cation exchange resin.
基金supported by the National Natural Science Foundation of China (No.22176067).
文摘The treatment and disposal of radioactive waste are presently facing great challenges.Spent ion exchange resins have become a focus of attention due to their high production and serious environmental risks.In this paper,a simplified model of cationic exchange resin is proposed,and the degradation processes of cationic resin monomer initiated by hydroxyl radicals(·OH)are clarified by combining statistical molecular fragmentation(SMF)model and density functional theory(DFT)calculations.The prediction of active sites indicates that the S-O bonds and the C-S bond of the sulfonic group are more likely to react during the degradation.The meta-position of the sulfonic group on the benzene ring is the most active site,and the benzene ring without the sulfonic group has a certain reactivity.The C11-C14 and C17-C20 bonds,on the carbon skeleton,are the most easily broken.It is also found that dihydroxy addition and elimination reactions play a major role in the process of desulfonation,carbon skeleton cleavage and benzene ring separation.The decomposition mechanisms found through the combination of physical models and chemical calculations,provide theoretical guidance for the treatment of complex polycyclic aromatic hydrocarbons.
基金provided by Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq,grant 130978/2020-5)to the Fundação de AmparoàPesquisa do Estado de São Paulo(FAPESP,grant 2019/11866-5)to CAPES for the financial support.
文摘This study assessed the adsorption process and the reaction kinetics involved in the selective recovery of vanadium from an acid solution containing iron as an impurity.Four commercial resins were studied:Lewatit^(®)MonoPlus TP 209 XL,Lewatit^(®) TP 207,Dowex^(TM)M4195(chelating resin)and Lewatit^(®) MonoPlus S 200 H(strong cationic exchange resin).To investigate the effect of time on the adsorption process,batch experiments were carried out using the following initial conditions:pH 2.0,298 K,and a proportion of 1 g of resin to 50 mL of solution.The variation of pH over time was analyzed.Chelating resin released less H+ions as the adsorption occurred,resulting in a lower drop of pH when compared to S 200 H resin.Ion adsorption by the resins was also evaluated through FT-IR and SEM−EDS before and after the experiments.Among the evaluated kinetic models(pseudo-first order,pseudo-second order,Elovich and intraparticle diffusion models),the pseudo-second order model best fits the experimental data of the adsorption of vanadium and iron by all of the four resins.M4195 resin showed the highest recovery of vanadium and the lowest adsorption of iron.Kinetic data,which are fundamental to industrial processes applications,are provided.
基金Scientific Research Foundation for the Returned Overseas Chinese Scholars by Ministry of Education of China (Grant No.[2004]527).
文摘To develop a simple and rapid purification method of rohitukine from the stem bark of Dysoxylum binectariferum. A L9 (34) orthogonal test was designed to optimize the extraction condition. Rohitukine in the plant extract was purified by using solvent-solvent partition and cation exchange resion (CER). Five different types of packing materials, including XAD-2 resin, polyamide, Sephadex LH-20, ODS and CER, were compared and CER showed the best capacity for rohitukine separation. The purification procedure was optimized as follows: the plant material powder was extracted with 70% ethanol (v/m = 60) by ultrasonic agitation for 60 min, then the 70% ethanol extract was dissolved in aqueous solution (pH 1, adjusted with 0.5 mol/L HCl) and extracted with equal volume of n-butanol. The aqueous layer was retained and the pH was adjusted to 10 with 25% aqueous ammonia and a solventsolvent partition was performed with equal volume of n-butanol. The obtained n-butanol extract was dissolved in aqueous solution (pH 1, adjusted with 0.5 mol/L HCl), and purified by a CER column eluting with H2O and 70% ethanol (pH 10, adjusted with 25% aqueous ammonia), successively. Rohitukine existed in 70% ethanol eluate, with a purity up to 53.3%. The method developed in this study provides a simple and rapid approach for the preparation of rohitukine from the stem bark ofD. binectariferum.