Adsorption and desorption behaviour of taurine on macroporous adsorption resins

Adsorption of taurine on S‐8, NKA2 and Amberlite XAD‐1 resins was measured with respect to time and the results indicated that equilibrium was reached in 50 min. The adsorption isotherms of taurine on D4006, AB‐8, S‐8, NKA2 were recorded and compared with those using Amberlite XAD‐1, XAD‐3, XAD‐6 and XAD‐7 at 28 °C. For an aqueous concentration range of 0–100 mg g^?1, each isotherm could be represented as a straight line. S‐8 and XAD‐1 resins had the highest solid/liquid distribution coefficients of 0.92 and 0.9. Since the locally produced S‐8 resin is less expensive than XAD‐1 resin, it was selected for further studies with adsorption isotherms being measured over the aqueous concentration range of 0–160 mg g^?1. These experimental results could be fitted by the Langmuir equation. The effects of pH, salting‐out and temperature on the adsorption were studied with the results showing that the influence of temperature was the most important. A temperature‐swing adsorption process was then tested to separate taurine from aqueous solutions and gave a overall yield >90% when taurine was adsorbed at 28 °C and eluted by deionized water at 70 °C. © 2001 Society of Chemical Industry     

Equilibria,Kinetics, and Mechanisms for the Adsorption of Four Classes of Phenolic Compounds onto Synthetic Resins

The adsorption of five phenolic compounds of four different classes from aqueous batch solutions onto four styrene-divinylbenzene and acrylic resins (EXA 90, EXA 118, XAD 7, and XAD 16) was investigated regarding their equilibria, kinetics and surface-energy heterogeneity, and mechanisms of adsorption. The experimental equilibrium data were very well fitted to Langmuir and Freundlich models (R ² > 0.900). Three kinetic models (pseudo-first-order, pseudo-second-order, and an intra-particle diffusion model) were suitable for describing the experimental data, the pseudo-second-order kinetic model being the best one (p < 0.001). The adsorption energy values were low (<19.00 kJ/mol), suggesting a physical adsorption process. Driving forces involved in the adsorption of the phenolic compounds onto the resins were hydrogen bonding, π ? π stacking and hydrophobic interactions.     

Recovery of 1,4‐Dimethyl Piperazine from Aqueous Solutions Using Polymeric Adsorbent and Ion‐Exchange Resins

Abstract

Strong and weakly acidic ion exchange resins and polymeric adsorbents are used for recovery of 1,4‐dimethyl piperazine (DMP) from aqueous solutions. Sorption of the amine in undissociated form is the primary mechanism of uptake of DMP on the ion‐exchange resins. Equilibrium adsorption data for DMP on the resins, at various temperatures, are fitted in Langmuir adsorption isotherm. Kinetic studies show that intraparticle diffusional resistance controls the sorption of DMP into the resin matrix. A mathematical model based on intraparticle diffusion and external mass transfer is used for simulating breakthrough profiles and compared with the experimental results for a fixed bed of weakly acidic Indion‐652 resin. The DMP loaded bed of the resin was effectively regenerated with methanol.     

Methylamino‐group‐modified hypercrosslinked polystyrene resin for the removal of phenol from aqueous solution

Chemical modification was performed for macroporous crosslinked chloromethylated polystyrene. The obtained HJ‐K01 resin was used to remove phenol from aqueous solution, and its adsorption behaviors for phenol were compared with commercial Amberlite XAD‐4. The results indicate that methylamino groups were successfully uploaded onto the surface of the HJ‐K01 resin and the adsorption capacity of phenol onto the HJ‐K01 resin was much larger than that onto XAD‐4. Furthermore, the original phenol solution was suitable for the adsorption, the adsorption isotherms could be fitted by the Freundlich model, and its kinetic curves could be characterized by a pseudo‐second‐order rate equation. The fixed‐bed column adsorption demonstrated that the HJ‐K01 resin was an excellent resin for the removal of phenol. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The Effect of Degree of Impregnation in Amberlite Resins with Organophosphorous Extractants for Y(III), La(III), Ce(III), Th(IV) and U(VI) Ions

Abstract

Background: The sorption of Y(III), La(III), Ce(III), U(VI) and Th(IV) ions with solvent impregnated resins using diphenylphosphate (DPP), and diphenylphosphinic acid (DPPA) as extractant and Amberlite XAD 16 and Amberlite XAD 2000 as a polymeric support has been studied. The impregnated resins containing various amounts of extractants (10/90, 20/80, 50/50, 60/40) have been prepared by a dry method. The effects of pH, types of extractant, extractant content, surface area of polymeric support and contact time have been investigated by batch method.

Results: The impregnation for DPP on XAD‐16 and XAD‐2000 was 111 and 46% at 60/40 extractant/resin mass ratio, respectively. The impregnation of DPPA at all ratios on both resins was found constant and lower than DPP. The sorption percentage of studied metal ions was within 90‐99% for DPP and DPPA on both resins after 20/80 extractant/resin mass ratio.

Conclusions: The sorption of DPP on Amberlite XAD 16 and XAD 2000 resins is rather more than DPPA. It could be seen that 20/80 extractant/resin mass ratio is generally adequate for single metal analysis where 60/40 could be suitable for multi‐metal analysis.     

大孔吸附树脂对红霉素的平衡吸附行为及其热力学性质

引言 红霉素(EM)是临床应用较多的一种大环内酯类抗生素,随着一些疗效更好的半合成衍生物的开发,红霉素原料需求呈现增长趋势.     

Adsorption studies of Cr(III) ions from aqueous solutions by DEHPA impregnated onto Amberlite XAD7 – Factorial design analysis

The present paper investigates the adsorption of Cr(III) ions using the SIR, prepared by impregnation of Amberlite XAD7 with di-(2-ethylhexyl)-phosphoric acid (DEHPA), which has been chosen as an extractant for the purpose of this study. The Amberlite XAD7–DEHPA resin was impregnated with DEHPA and ethylic alcohol as solvent trough dynamic column impregnation method. The influence of different physicochemical parameters (pH, resin dosage, initial concentration of Cr(III) ions, contact time and temperature) upon the adsorption capacity of XAD7–DEHPA, in the Cr(III) ions removal process from aqueous solution, has been investigated. The pH for Cr(III) ions adsorption was found as 3.0 for this material. The results showed that the adsorption equilibrium was reached after 45 min. The adsorption process is best described by the pseudo-second order kinetic model. Langmuir adsorption isotherm gave a satisfactory fit of the equilibrium data. The maximum adsorption capacity is ∼3 mg Cr(III) ions/g SIR. The thermodynamic studies allowed us to determine the thermodynamic parameters ΔG°, ΔH° and ΔS°. In this paper the factorial design of experiments was used to study the performance of the adsorption process.     

Adsorption of salicylic acid in aqueous solution by a water‐compatible hyper‐cross‐linked resin functionalized with amino‐group

On account of the high toxicity of nitrobenzene, 1,2‐dichloroethane was used as solvent. A novel water‐compatible hyper‐cross‐linked resin functionalized with amino‐group (denoted as GQ‐04) was synthesized to remove salicylic acid (SA) in aqueous solution. The maximum adsorption capacity of SA onto GQ‐04 was observed at pH of 1.88. The adsorption capacity increased with the increasing salt concentration. The adsorption kinetic data obeyed the pseudo‐second‐order rate equation and the adsorption isotherms can be characterized by Freundlich model. The intraparticle diffusion was the main rate‐controlling step. The saturated adsorption quantity of SA was up to 119.9 mg·mL‐1 according to the dynamic adsorption at 293 K. The resin could be regenerated by the 6 BV mixed solution of 80% ethanol and 0.5 mol/L NaOH. The size matching and hydrogen bonding between GQ‐04 and SA and the micropore structure resulted in the larger adsorption capacity in comparison with XAD‐4 and H103 resin. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Surface and Lateral Interactions of Nonylphenol Nonionic Surfactants with Porous Resin

The adsorption process between porous resins with different surface properties and nonylphenol non-ionic surfactants of the same hydrocarbon chain length but varying oxyethylene units was investigated. The adsorption of NPEOn with shorter EO chains is greater than those with longer EO chains on the surfaces of resins, and the strength of the adsorption was affected by resin surface-surfactant and surfactant-surfactant lateral interactions. Lateral interactions are endothermic, and contribute more to the adsorption process on aminated resins (MN-100, MN-150) than on hyper-crosslinked resins (MN-200, NDA-150). The surface interactions are mainly due to bonding between the hydrophobic moiety of the surfactant and hydrophobic surfaces of the resins without electrical interaction or hydrogen bonding, even on aminated resins (MN-100, MN-150). Positive ΔH values indicate that the adsorption process is endothermic overall, which is supported by the increase in adsorption capacity observed with increasing temperature.     

Removal of amino acids from water by adsorption on polystyrene resins

The adsorption of eight amino acids, L ‐asparagine, D,L ‐threonine, L ‐lysine, L ‐leucine D,L ‐methionine, L ‐tyrosine, L ‐phenylalanine and D,L ‐tryptophan, on the non‐polar macroporous adsorbents Amberlite XAD‐2 and XAD‐4 (polystyrene–divinylbenzene copolymers) was studied. Equilibrium adsorption experiments were conducted to estimate the types of isotherm and their parameters. The effect the chemical composition and structure of the amino acids on the efficiency of adsorption was evaluated. The influence of pH and ionic strength was also studied. The data of adsorption isotherms of the examined amino acids seemed generally to approach the Freundlich isotherm model. Tryptophan isotherm adsorption data could match in some cases the Langmuir model. The majority of the adsorption isotherms were almost linear. In terms of adsorbed amino acid on both resin surfaces, the amino acids can be ranked thus: D,L ‐tryptophan > L ‐phenylalanine > D,L ‐methionine, L ‐tyrosine > L ‐leucine > L ‐lysine > D,L ‐threonine > L ‐asparagine. In low pH solution, adsorption was generally higher than that at intermediate and high pH values. Generally, as the ionic strength increases, the adsorption of the amino acids increases. © 2001 Society of Chemical Industry     

IMPREGNATED RESINS CONTAINING DI-(2-ETHYLHEXYL) THIOPHOSPHORIC ACID FOR THE EXTRACTION OF PALLADIUM(II). I. PREPARATION AND STUDY OF THE RETENTION AND DISTRIBUTION OF THE EXTRACTANT ON THE RESIN.

ABSTRACT

Solvent impregnated resins containing di-(2-ethylhexyl) thiophosphoric acid(DEHTPA) were prepared by direct adsorption of the extractant onto Amberlite XAD2 using a dry impregnation method. The impregnated resins were characterized by means of potentiometnc titrations and specific surface area measurements, and a new method to determine DEHTPA content in the resin based on surface area measurements, is proposed. The distribution of DEHTPA between the aqueous phase and the resin phase was studied, and the data obtained     

Selective Solubilization of Nitrophenols and Adsorption on Ion Exchange Resins in Nonaqueous Conditions

Abstract

Separation of nitrophenols (NP) has been studied by selective solubilization in organic solvents of different polarities. o‐NP dissolves very well in heptane and toluene while intermolecular hydrogen bonding among p‐NP molecules decreases its solubilization in these solvents. Thus partial separation of o‐/p‐nitrophenols is achieved by selective solubilization of o‐NP in heptane. The trace amounts of p‐NP from the o‐NP solutions are removed by its selective sorption on basic ion exchange resins. The sorption of nitrophenols, individually and in mixtures, is experimentally determined from their solutions in heptane, toluene, and methanol by using weakly basic Indion‐850 and Duolite A‐308 resins and strongly basic Indion‐810 resin. The equilibrium adsorption studies show very selective adsorption of p‐NP from heptane with a high loading capacity on Indion‐850.     

Adsorption of Cr(III), Ni(II), Zn(II), Co(II) ions onto phenolated wood resin

In this study, phenolated wood resin was used an adsorbent for the removal of Cr(III), Ni(II), Zn(II), Co(II) ions by adsorption from aqueous solution. The adsorption of metal ions from solution was carried at different contact times, concentrations and pHs at room temperature (25°C). For individual metal ion, the amount of metal ions adsorbed per unit weight of phenolated wood resin at equilibrium time increased with increasing concentration and pH. Also, when the amounts of metal ions adsorbed are compared to each other, it was seen that this increase was order of Cr(III) > Ni(II) > Zn(II) > Co(II). This increase was order of Cr(III) > Ni(II) > Co(II) > Zn(II) for commercial phenol–formaldehyde resin. Kinetic studies showed that the adsorption process obeyed the intraparticle diffusion model. It was also determined that adsorption isotherm followed Langmuir and Freundlich models. Adsorption isotherm obtained for commercial phenol–formaldehyde resin was consistent with Freundlich model well. Adsorption capacities from Langmuir isotherm for commercial phenol–formaldehyde resin were higher than those of phenolated wood resin, in the case of individual metal ions. Original adsorption isotherm demonstrated the monolayer coverage of the surface of phenolated wood resin. Adsorption kinetic followed the intraparticle diffusion model. The positive values of ΔG° determined using the equilibrium constants showed that the adsorption was not of spontaneous nature. It was seen that values of distribution coefficient (K_D) decreasing with metal ion concentration in solution at equilibrium (C_e) indicated that the occupation of active surface sites of adsorbent increased with metal ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2838–2846, 2006     

Recovery of Organic Acids Using Ion‐Exchanger‐Impregnated Resins

The recovery of organic acids from aqueous solutions using ion‐exchanger‐impregnated resins has been investigated. The key parameters for process design are equilibria, mass transfer kinetics and loss of the liquid ion exchanger (bleeding). The maximum bleeding was observed when the resin was used for the first time. The ion exchanger concentration in the aqueous phase decreases to a final concentration lower than 1mg/L after the first usage. The equilibria of citric and tartaric acid have been investigated for the different macroporous resins XAD4 and XAD16 impregnated with tri‐n‐octylamine (TOA). A modified Langmuir isotherm taking the loading of ion exchanger TOA on the resin into account is able to describe the equilibrium in both test systems in dependence of the temperature. Experiments in a stirred vessel have been carried out to characterize the intraparticular mass transfer. The results have been used to predict the effective pore diffusion coefficient using the tortuosity.     

Selective adsorption of oleuropein from olive (Olea europaea) leaf extract using macroporous resin

Extraction, optimization, and adsorption of oleuropein from olive (Olea europaea) leaves were carried out, respectively. Face-centered composite design model was chosen for designing the experimental conditions for extraction of olive leaves through response surface methodology. Olive leaf extract obtained under the optimum conditions was concentrated by several macroporous resins (Amberlites XAD 2, XAD 4, XAD 7HP, and XAD 16). The crude and purified extracts were evaluated according to their total phenolic material (TPM) and oleuropein concentration. XAD 7HP showed the best performance regarding adsorption (91%) and desorption ratio (97%) for oleuropein. Pseudo-first- and second-order and Elovich kinetic models were efficient to represent the experimental data for the adsorption of TPM and oleuropein with high correlation coefficients. Equilibrium data were fitted to Langmuir and Freundlich isotherms at four different temperature values. The antioxidant capacity of the extracts was evaluated with several assays such as Cupric ion reducing antioxidant capacity, 2,2-diphenyl-1-picrylhydrazyl, and 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt.     

Modified macroporous adsorption resins with amino and acetyl groups through a novel method and adsorption behaviors for alizarin yellow GG

Under bubble with air compressor, macroporous adsorption resin was functionalized with amino and acetyl groups. The method avoided the fragmentation of the resin during modification. Alizarin yellow GG (AYGG) was used as an adsorbate to investigate adsorption kinetics of the modified resins. It showed that pseudofirst‐order and pseudosecond‐order kinetics cannot reasonably express the adsorption process. A new kinetic model, multi‐layer adsorption model, showed much better fit to the adsorption kinetic data and corresponding kinetic parameters could predict adsorption mechanism. Meantime, AYGG can be easily recovered, and the resins can be regenerated. Due to π – π , electrostatic force and hydrogen bond interaction between the resin and carboxyl, phenolic hydroxyl, and azo groups of AYGG, the resin with amino group showed higher adsorption capacity than the other resins used in this study. Steric hindrance and decrease in electrostatic force were unfavorable for the enrichment of AYGG by the resin with acetyl group. Response surface model combining with central composite design was used to determine effects of pH and initial concentration on adsorption. It showed that a second‐order polynomial regression model could reasonably express the experimental data and optimum adsorption conditions were obtained. The design provided an effective methodology to optimize an adsorption process. POLYM. ENG. SCI., 54:1960–1968, 2014. © 2013 Society of Plastics Engineers     

Adsorption of 1,3-propanediol from synthetic mixture using polymeric resin as adsorbents

The aim of this work was to separate 1,3-PDO from a synthetic mixture using polymeric resins, Amberlite XAD-7 and XAD-16 resins. The equilibrium adsorption of 1,3-PDO onto two polymeric resins were investigated in binary and tertiary systems. Experimental results of binary component adsorption equilibrium indicated that the adsorption capacity (q) of 1,3-PDO at 160 g/L onto XAD-7 and XAD-16 was 835.96 and 584.61 mg 1,3- PDO/g dry resin, respectively. The adsorption isotherms were closely predicted by the Langmuir-Freundlich model among the two isotherm model tested. The value of n of 1,3-PDO adsorbed on XAD-7 are much higher than those on XAD-16. This result suggested that XAD-7 resin has a higher affinity for the 1,3-PDO adsorption than XAD-16 resin. Moreover, the value of adsorption capacity of 1,3-PDO in the binary and tertiary component were compared at the same conditions. In the tertiary system, although the selectivity of 1,3-PDO from XAD-7 was approximately six times higher than XAD-16, the adsorption capacity of 1,3-PDO at 160 g/L onto XAD-16 was higher than XAD-7. Interestingly, the reusability of XAD-7 and XAD-16 resins in the three cycle times shows a slight loss of adsorption capacity. Furthermore, the investigation about desorption by an ethanol/water mixture at 50% (V/V) indicated that the desorption yield of 1,3-PDO from XAD-7 was lower than XAD-16 resin for both the binary and tertiary component. This was due to the more favorable adsorption characteristics of XAD-7 resin than XAD-16 resin.     

Synthesis,characterization, and application of amberlite XAD‐2‐ salicylic acid‐ iminodiacetic acid for lead removal from human plasma and environmental samples

A new chelating resin is prepared by coup‐ling Amberlite XAD‐2 with salicylic acid (SAL) through an azo spacer. Then the polymer support was coupled with iminodiacetic acid (IDA). The resulting sorbent has been characterized by FT‐IR, elemental analysis, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) and studied for the preconcentration and determination of trace Pb (II) ion from human biological fluid and environmental water samples. The optimum pH value for sorption of the metal ion was 5. The sorption capacity of functionalized resin is 67 mg g⁻¹. The chelating sorbent can be reused for 20 cycles of sorption–desorption without any significant change in sorption capacity. A recovery of 95% was obtained for the metal ion with 0.5M nitric acid as eluting agent. The profile of lead uptake on this sorbent reflects good accessibility of the chelating sites in the Amberlite XAD‐2‐SAL/IDA. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The equilibrium adsorption data of Pb (II) on modified resin were analyzed by Langmuir, Freundlich, Temkin, and Redlich‐Peterson models. Based on equili‐brium adsorption data the Langmuir, Freundlich, and Temkin constants were determined 0.428, 20.99, and 7 × 10⁻¹² at pH 5 and 20°C. The method was successfully applied for determination of lead ions in human plasma and sea water sample. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

高聚物吸附剂的孔隙结构和表面特性对苯酚吸附容量的影响

引　言苯酚广泛应用于石油、煤矿、塑料等工业领域 ,因而含酚废水的产生相当普遍[1] 苯酚是强毒性物质 ,排放未经处理的含酚废水会造成严重的环境污染 ,国内外已将苯酚列为重点控制的污染物之一[2 ,3] 对含酚废水的治理技术有微生物降解、溶剂萃取、化学氧化、焚烧、吸附等 ,其中吸附法以其操作简便、成本低廉而备受关注 ,尤其适合于低浓度含酚废水污染的控制[4 ] 活性炭具有巨大的比表面积 ,对有机污染物具有较强的吸附能力 ,但有效的再生技术仍有待解决[5] 多孔固体高聚物吸附　　材料由于具有较大比表面 ,与活性炭相比容易再生[6 ] ,…