Selective adsorption behavior of Cd(II) ion imprinted polymers synthesized by microwave-assisted inverse emulsion polymerization: Adsorption performance and mechanism

Zhu, Fang; Li, Luwei; Xing, Junde

doi:10.1016/j.jhazmat.2016.09.012

Cited by 115 publications

(37 citation statements)

References 21 publications

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“…Both pseudo first-order and pseudo second-order kinetics models can be used to fit the removal of Cr(VI) by G-nZVI. These results illustrated that the reaction included prompt adsorption and simultaneous redox process 17,37 . The rate constants, k obs1 and k obs2 , increase from 0.0091 to 0.0968 min −1 and from 0.0121 to 0.0746 L•mg −1 •min −1 for the homogeneous system, from 0.0026 to 0.0252 min −1 and from 0.0042 to 0.0257 L•mg −1 •min −1 for the heterogeneous system, respectively, when the concentration of Fe 2+ solution in the synthesis of G-nZVI increases from 0.05 to 0.20 M. This demonstrated that the removal rate depended on the concentration of Fe 2+ and the active sites on the surface of G-nZVI 17 .…”

Section: Xps Characterization Xps Analysis Was Conducted To Understamentioning

confidence: 73%

“…This indicates that a chemical adsorption is the dominated step to control the reaction rate in the homogeneous and heterogeneous systems due to the assumption of the pseudo second-order kinetics, which is based on the imagination that the adsorption rate is controlled by the chemical adsorption mechanism. The chemical adsorption process involves sharing and transferring of electrons between adsorbent and Cr(VI) 37 .…”

Section: Xps Characterization Xps Analysis Was Conducted To Understamentioning

confidence: 99%

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The comparative study of a homogeneous and a heterogeneous system with green synthesized iron nanoparticles for removal of Cr(VI)

Guo

2020

Sci Rep

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Green iron nanoparticles (G-nZVi) were synthesized in situ by adding grape-seed extracts and fe 2+ solution simultaneously. the performances for the removal of cr(Vi) were compared in a homogeneous system by original G-nZVi (in suspension) with in a heterogeneous system by treated G-nZVi. the characterization of teM, SeM, XRD, ftiR and XpS show that G-nZVi is the formation of fe°-iron oxide core-shell nanoparticles with organic matters in the extracts as capping/stabilizing agents. the same excellent performances on the removal of cr(Vi) were observed in the both systems and the adsorption capacity was from 78.3 to 166.7 mg (Cr)•g −1 (fe) with the increase of initial fe 2+ concentrations. the pseudo second-order model described the adsorption process excellently and both pseudo first-order and pseudo second-order models fit the reduction process well. It illustrated that the reaction included prompt adsorption and simultaneous redox process. Moreover, the results of thermodynamics study (ΔG° < 0, ΔH° > 0, ΔS° > 0) revealed that the adsorption was a spontaneous and endothermic process. it is obvious that the systhesis of original G-nZVi in the homogeneous system is more simple, rapid, cost-effective and suitable for in situ uses. it holds a great potential for remediation of soil and water. Chromium is one of the most common heavy metals because of its chemical stability and low biodegradability 1-3. Hexavalent chromium (Cr(VI)) is 100-fold times more toxic than trivalent chromium (Cr(III)) and highly soluble in water 4. Hence, Cr(VI) can get into aquatic ecosystems such as underground water and contaminate drinking water 5,6. Various chemical and physical treatments are employed for the Cr(VI) removal from the aqueous solution, such as membrane separation 7 , coagulation and flocculation 8 , adsorption and biosorption treatments 9-11 , Among the treatments, adsorption technique is advantageous due to its effectiveness, easiness in operating and less generation of chemical sludge. In the current trend, nanotechnology has been widely preferred because of the huge specific surface area 12. Nano-scale zero-valent iron (nZVI) plays a crucial role for environmental remediation due to its strong reducing power and its ability to adsorb many important contaminants such as heavy metals 13. In fact, the most suitable method of Cr(VI) removal should include the reduction of Cr(VI) to Cr(III), since Cr(III) is significantly less toxic, much lower aqueous solubility and mobility than Cr(VI). Hence, nZVI based techniques have been widely employed in the removal of Cr(VI) 14,15. However, nZVI particles tend to aggregate rapidly and thereby reduce the specific surface area and diminish particles reactivity. Various stabilization techniques have been applied to improve nZVI dispersibility, such as protective coatings 3,16 and solid supports 9,10,17. In recent years, green synthesis of nZVI has been received growing attention and developed as a promising alternative for chemical and physical methods, due to its advantages of a sim...

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Section: Xps Characterization Xps Analysis Was Conducted To Understamentioning

confidence: 73%

Section: Xps Characterization Xps Analysis Was Conducted To Understamentioning

confidence: 99%

The comparative study of a homogeneous and a heterogeneous system with green synthesized iron nanoparticles for removal of Cr(VI)

Guo

2020

Sci Rep

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“…Widely used adsorbents include carbonaceous materials, clays, zeolites, composite materials, biomass, nanomaterials, and polymeric materials [ 6 , 7 , 8 ]. The efficiency of adsorbents depends on their specific surface areas and their chemical stabilities [ 9 ]. Therefore, the choice of suitable materials for the adsorption of heavy metal ions from wastewater is very important.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of Cu(II) and Zn(II) Ions from Aqueous Solution by Gel/PVA-Modified Super-Paramagnetic Iron Oxide Nanoparticles

Anudari

Yin

et al. 2018

Molecules

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Super-paramagnetic iron oxide nanoparticles (SPIONs)/gelatin (gel)/polyvinyl alcohol (PVA) nanoparticles were designed and synthesized by the co-precipitation method and further modified with gel and PVA. These nanoparticles were used for the removal of Cu(II) and Zn(II) from aqueous solutions. The adsorbents were rich in different functional groups for chemisorption and showed effective adsorption properties. The adsorption of Cu(II) and Zn(II) on the SPIONs/gel and SPIONs/gel/PVA materials were investigated with respect to pH, adsorption kinetics, and adsorption isotherms. The adsorption data was fitted to the Langmuir, Freundlich, and Sips models at the optimum pH 5.2 (±0.2) over 60 min; SPIONs/gel showed maximum adsorption capacities of 47.594 mg/g and 40.559 mg/g for Cu(II) and Zn(II); SPIONs/gel/PVA showed those of 56.051 mg/g and 40.865 mg/g, respectively. The experimental data fitted the pseudo-second-order model, indicating that the process followed chemical monolayer adsorption. In addition, the SPIONs/gel/PVA showed better stability and Cu(II) adsorption efficiency than SPIONs/gel.

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“…The negative values of entropy Δ S suggested the decreased randomness at the solid-liquid interface during the adsorption of 2-aminopyridine onto both absorbents. Finally, the obtained negative ΔH values also further confirmed the exothermic nature of the adsorption process [ 44 ].…”

Section: Resultsmentioning

confidence: 53%

Selective Removal of the Genotoxic Compound 2-Aminopyridine in Water using Molecularly Imprinted Polymers Based on Magnetic Chitosan and β-Cyclodextrin

Zhang

Zhu

Zhang

et al. 2017

IJERPH

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To develop efficient materials with enhanced adsorption and selectivity for genotoxic 2-aminopyridine in water, based on magnetic chitosan (CTs) and β-cyclodextrin (β-CD), the magnetic molecularly imprinted polymers (MMIPs) of Fe3O4-CTs@MIP and Fe3O4-MAH-β-CD@MIP were synthesized by a molecular imprinting technique using 2-aminopyridine as a template. The selective adsorption experiments for 2-aminopyridine were performed by four analogues including pyridine, aniline, 2-amino-5-chloropyridine and phenylenediamine. Results showed the target 2-aminopyridine could be selectively adsorbed and quickly separated by the synthesized MMIPs in the presence of the above structural analogues. The coexisting ions including Na+, K+, Mg2+, Ca2+, Cl− and SO42− showed little effect on the adsorption of 2-aminopyridine. The maximum adsorption capacity of 2-aminopyridine on Fe3O4-CTs@MIP and Fe3O4-MAH-β-CD@MIP was 39.2 mg·g−1 and 46.5 mg·g−1, respectively, which is much higher than values in previous reports. The comparison result with commercial activated carbon showed the obtained MMIPs had higher adsorption ability and selectivity for 2-aminopyridine. In addition, the synthesized MMIPs exhibited excellent performance of regeneration, which was used at least five times with little adsorption capacity loss. Therefore, the synthesized MMIPs are potential effective materials in applications for selective removal and analysis of the genotoxic compound aminopyridine from environmental water.

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Selective adsorption behavior of Cd(II) ion imprinted polymers synthesized by microwave-assisted inverse emulsion polymerization: Adsorption performance and mechanism

Cited by 115 publications

References 21 publications

The comparative study of a homogeneous and a heterogeneous system with green synthesized iron nanoparticles for removal of Cr(VI)

The comparative study of a homogeneous and a heterogeneous system with green synthesized iron nanoparticles for removal of Cr(VI)

Adsorption of Cu(II) and Zn(II) Ions from Aqueous Solution by Gel/PVA-Modified Super-Paramagnetic Iron Oxide Nanoparticles

Selective Removal of the Genotoxic Compound 2-Aminopyridine in Water using Molecularly Imprinted Polymers Based on Magnetic Chitosan and β-Cyclodextrin

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