Search

An organic polymeric resin was synthesized by anchoring p-aminobenzoic acid onto macroporous chloromethylated polystyrene beads, and was used for Zn(II) removal from aqueous solutions. The resin exhibited an initially rapid adsorption property for Zn(II) with equilibrium time of 10 h and the maximum adsorption capability approached 184.5 mg g−1. Optimum pH was 4.5. The mechanism of adsorption was investigated using kinetic, isotherm and thermodynamic models. The adsorption kinetic data were described well by a pseudo second-order model with R2 of 0.997. There was a negative Δ G (−17.98 kJ mol−1) and positive Δ H (13.58 kJ mol−1). HCl solution (1.0 mol l−1) could achieve an elution rate of 100%. The experimental data were well fitted by the Thomas model with R2 of 0.9826. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Box–Behnken design of the response surface methodology was employed to optimize three most important adsorption parameters (initial Ni(II) concentration, pH, and adsorption temperature) and to investigate the interactive effects of these variables on Ni(II) adsorption capacity of 110-H resin. According to analysis of variance and response surface analyses, the experiment data were excellently fitted to the quadratic model. The corresponding optimal parameters of adsorption process are listed as following: temperature at 35°C, initial pH of 6.57, and initial Ni(II) concentration of 0.33 mg/mL. Under optimum adsorption conditions, the adsorption capacity of Ni(II) was 188.5 mg/g, in well accordance with the predicted value by the model (192.88 mg/g). The adsorption kinetics and equilibrium data were well fitted to the pseudo-second-order model and the Langmuir isotherm model, respectively. Thermodynamic parameters (ΔG, ΔS, and ΔH) suggested that the adsorption process was endothermic and spontaneous in nature. Desorption study revealed that Ni(II) can be effectively eluted by 2.0 mol/L HCl solution, and the recovery was 100%. The characterization by Fourier Transform infrared and SEM was performed. Meanwhile, the 110-H resin has been successfully applied in the removal of Ni(II) in natural water samples with satisfactory results. [ABSTRACT FROM PUBLISHER]

The adsorption and desorption behaviors of La(III) on SQD-85 resin were investigated using batch and column methods. Batch adsorption studies were carried out with different pH, contact time, and temperature. In the batch system, the SQD-85 resin exhibited the highest La(III) uptake as 478 mg/g at 308 K, at an initial pH value of 6.5. The adsorption of La(III) follows the Langmuir isotherm better than Freundlich isotherm. The thermodynamic parameters such as the positive value of ∆Hshowed that the adsorption was endothermic in nature and ∆G, which were all negative, indicated that the adsorption of La(III) ions onto SQD-85 resin was spontaneous. Column adsorption experiments indicated the maximum adsorption capacity of 481 mg/g for La(III), and Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. The desorption rate of La(III) was 99.8% when the elution agent is 1.0 mol/L HCl solution. These results suggest that La(III) in aqueous solution can be removed and recovered by SQD-85 resin efficiently. [ABSTRACT FROM PUBLISHER]

A novel chelating resin, polyacrylonitrile-2-amino-1,3,4-thiadiazole (PAN-ATD), was prepared via one-step reaction and its structure was characterized by elemental analysis and FT-IR. The adsorption properties of the resin for Hg(II) were investigated by batch and column experiments. Batch adsorption results showed that PAN-ATD had high affinity towards Hg(II) and the maximum adsorption capacity estimated from the Langmuir model was 526.9 mg/g at 308 K. The adsorption kinetic and equilibrium data were well fitted to the pseudo-second-order model and the Langmuir isotherm model, respectively. Furthermore, the resin can be easily regenerated and reused with less than 10% loss of adsorption capacity. Also, the resin and its metal complexes were studied by SEM, TGA, and energy dispersive X-ray spectroscopy (EDS). With good overall properties (a high selectivity adsorption capacity, easy to be regenerated and stable application capacity) PAN-ATD resin can not only be used in selective removal of Hg(II) from waste solution, but also be used for preparation of the separation and enrichment column applied in the analysis and detection area. [ABSTRACT FROM AUTHOR]

A novel chelating resin, polyacrylonitrile-2-aminothiazole(PAN-AT), was synthesized simply by the reaction of polyacrylonitrilewith 2-aminothiazole. Optimization of the PAN-AT synthesis was carriedout at different temperatures, different molar ratios of reagents,and different time intervals in N,N-dimethylformamide (DMF) using response surface methodology (RSM)for the first attempt. The functional group capacity (the contentof the functional group) and the percentage conversion of the functionalgroup of PAN-AT prepared under the optimum conditions were 3.94 mmol/gand 41.10%, respectively. The structure of PAN-AT was characterizedby elemental analysis and FTIR. Meanwhile, the adsorption propertiesof the resin for Hg(II) were investigated by batch and column experiments.The results suggested that the resin possessed much better adsorptioncapability for Hg(II) than for other metal ions and the maximum saturatedadsorption capacity estimated from the Langmuir model was 454.9 mg/gat 308 K. Furthermore, the resin could be regenerated through thedesorption of the Hg(II) anions using 3.0 mol/L HNO3solutionand could be reused to adsorb again. Finally, the resin and its metalcomplexes were studied by SEM, TGA, and energy dispersive X-ray spectroscopy(EDS). Also, the PAN-AT chelating resin could provide a potentialapplication for a treatment process of Hg(II) contaminated wastewater. [ABSTRACT FROM AUTHOR]

Abstract: A novel ethylenediamine functionalized chelating resin (ED resin) with simple technology, high adsorption capacity and significant selectivity was synthesized. It was characterized by elemental analysis and infrared spectra, and was applied for determination of metal ion in tea samples. The optimized synthesis conditions is molar ratio ED:Cl=2:1, 100°C as reaction temperature and DMF as solvent. ED resin can be used in separating Cu(II) from aqueous solutions. The adsorption processes were evaluated by Langmuir and Freundlich isotherms. Pseudo-second-order kinetics showed better accordance. Thermodynamic parameters indicated that adsorption process was spontaneous and endothermic. Thomas model was applied to determine the characteristic parameters of column useful for process design. Finally, Cu(II) can be eluted by 1.0molL−1 HCl solution. AAS method was applied for copper determination after the pre-concentration step, and the results indicated that ED resin is essentially free from interferences, which can contribute to accurate determination in waters and foods. [Copyright &y& Elsevier]

The adsorption and desorption behaviors of Pb2+ on D113-III resin were investigated with various chemical methods. The influence of operational conditions such as contact time, initial concentration, initial pH of solution, and temperature on the adsorption of Pb2+ has also been examined. The results show that the maximum uptake capacity of Pb2+ is 476.2 mg/g on D113-III resin at 298K at pH= 4.5 in HAc-NaAc medium. The adsorption of Pb2+ fitted the Langmuir isotherm better than the Freundlich isotherm. And kinetics on the adsorption of Pb2+ has been studied. The apparent activation energy Ea and adsorption rate constant k298 values are 5.22 kJ/mol and 5.82 x 10-5 s-1, respectively. The data of thermodynamic parameters whose ΔS value is 0.255 kJ/mol K and ΔH value is 45.29 kJ/mol indicate the endothermic nature of the adsorption process. And the negative value of ΔG showed that the adsorption of Pb2+ ions onto D113-III resin was spontaneous. The Thomas model was applied to experimental data obtained from column adsorption experiments. Finally, Pb2+ can be eluted by using 0.5 mol/L HCl solution and the resin can be regenerated and reused. And the sorption of Pb2+ on D113-III resin from simulated seawater is studied. [ABSTRACT FROM AUTHOR]

Indium and its compounds have numerous industrial applications in the manufacture of liquid crystal displays and semiconductors. They are considered hazardous substances. This article reports the research into the recovery of In(III) from aqueous solution by sorption. Cation-exchange carboxylic resin (D155 resin) was used as a sorbent for indium(III) ions extraction in this research. The factors of parameters, such as pH, kinetics, temperature and sorption isotherm, and column experiment were investigated. In batch system, D155 resin exhibited the highest In(III) ion uptake as 279 mg/g at 298 K with a pH value 5.00. The sorption data matched the Langmuir isotherms very well. The thermodynamic parameter ΔG was negative, and this result indicated that the sorption of In(III) ions on D155 resin was spontaneous. Furthermore, the positive value of ΔH showed that the sorption was endothermic in nature. In(III) ions can be eluted with 0.5 mol/L HCl solution. The Thomas model was applied to experimental column data to determine the characteristic parameters of the column which is useful for process design. [ABSTRACT FROM AUTHOR]

Abstract: Polystyrene-triethylenetetramine resin (PS-TETA) was synthesized from chloromethylated polystyrene (PS-Cl) and triethylenetetramine (TETA) and employed as a new adsorbent for heavy metal removal from aqueous solutions. The effects of reaction parameters (reaction solvent, molar ratio of reagents, reaction temperature and reaction time) on the functional group capacity of PS-TETA resin were monitored to specify the best synthesis conditions. The functional group capacity and conversion percentage of functional group of PS-TETA prepared under the optimum condition were 2.13mmol FG/g and 49.79%, respectively. The structure of PS-TETA was confirmed by elemental analysis and infrared spectra. The optimization of experimental conditions and parameters including pH, contact time, initial metal ion concentration for the removal of heavy metals were investigated. The maximum adsorption capacities of the resin for Hg(II), Cd(II) and Pb(II) evaluated from the Langmuir model were 344.8, 212.8 and 147.1mg/g, respectively. Desorption studies revealed that Hg(II), Cd(II) and Pb(II) can be easily removed from PS-TETA by altering the pH values of the solution using HCl, which indicate that PS-TETA is a promising adsorbent for heavy metals removal from aqueous medium. [Copyright &y& Elsevier]