Application of response surface methodology for thorium adsorption on PVA/Fe3O4/SiO2/APTES nanohybrid adsorbent

Mirzabe, Gholam Hossein; Keshtkar, Asghar

doi:10.1016/j.jiec.2014.11.040

Cited by 90 publications

(29 citation statements)

References 47 publications

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“…The Freundlich model describes the surface heterogeneity of the sorbent, indicating multilayer adsorption. The 1/ n value from the Freundlich model between 0.5 and 1.0, represents favorable adsorption; on the other hand, a value of 1/ n > 1 suggests weak adsorption bonds between the adsorbent and adsorbate, indicating unfavorable adsorption [ 41 ]. The 1/ n values from the Freundlich model for the adsorption of SPIONs/gel were 0.3164 and 0.3367 for Cu(II) and Zn(II); SPIONs/gel/PVA were those of 0.4373 and 0.4399, respectively.…”

Section: Resultsmentioning

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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Section: Resultsmentioning

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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“…Among these magnetic nanomaterials (MNPs), CoFe 2 O 4 MNPs have attracted much attention because of their unique physical and chemical capabilities, such as their high coercivity, magnetization, and mechanical hardness [ 13 , 14 ]. These characteristics make CoFe 2 O 4 MNPs ideal magnetic core carriers [ 15 ]. However, CoFe 2 O 4 -based core-shell carriers have little adsorption capacity for heavy metals [ 16 ] and usually have to be modified on their surface to obtain a high adsorption capacity.…”

Section: Introductionmentioning

confidence: 99%

A Mild and Facile Synthesis of Amino Functionalized CoFe2O4@SiO2 for Hg(II) Removal

et al. 2018

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To avoid the dangerous operational conditions, shorten the preparation time, and improve the adsorption performance of amino-functionalized nanomagnetic materials with a core–shell structure, a magnetic nanocomposite of CoFe2O4@SiO2 was successfully functionalized with amino group (−NH2) through a mild and facile hydrothermal method without the use of any toxic or harmful solvents at a relatively low temperature. The preparation time of the key steps of amino functionalization was shortened from 30 h to about 10 h. The core-shell structure and successful grafting were confirmed by various means. The amino-functionalized CoFe2O4@SiO2 was used for the removal mercury (Hg(II)), a heavy metal, and exhibited excellent magnetic properties and a high Langmuir adsorption capacity of 149.3 mg Hg(II)/g. The adsorption of Hg(II) onto CoFe2O4@SiO2–NH2 followed the pseudo-second-order kinetic equation and Langmuir model. The thermodynamic data showed that the Hg(II) adsorption process was achieved through spontaneous exothermic and monolayer adsorption with electrostatic adsorption and chemisorption. In addition, the as-prepared CoFe2O4@SiO2–NH2 nanoparticles had a good reusable value, good application performance and stability, and can provide a mild and facile way to remove heavy metals from aqueous solution.

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“…In the present experiment, PVA was used as a matrix owing to its good processability to form free-standing film, originating from its outstanding dispersibility in aqueous solution, flexibility, adhesion and oxygen barrier property. [31][32][33][34][35][36][37][38][39][40][41][42][43] As a result, PVA dispersed in solution was well infiltrated into the 3D hollow graphene structure via a dip-coating process, and free-standing graphene/PVA films of ca. 4.3 µm thickness were fabricated after drying at 70 °C.…”

Section: Resultsmentioning

confidence: 99%

Flexible free-standing composite films having 3D continuous structures of hollow graphene ellipsoids

et al. 2015

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Graphene composites have great potential in electrical and electronic applications due to their outstanding physicochemical, electrical, and mechanical properties. Unfortunately, current graphene preparation technologies allow the exploitation of only an exceptionally low percentage of graphene's capability. Herein, free-standing graphene films based on three-dimensional (3D) continuous structures of hollow graphene ellipsoids were successfully fabricated, whose composite structure has never been investigated. Positively charged polystyrene (PS) spheres were first wrapped with negatively charged graphene upon simple mixing, and became ellipsoids by stretching. Due to their improved continuity, composites based on the ellipsoids and spherical microparticles have lower sheet resistances than those based on spherical nanoparticles. Upon folding and application of pressure, composites based on the hollow graphene ellipsoids exhibited superior electrical conductivity and structural stability owing to their high mechanical strength and effective electron transport pathway. The ability to control the face-contact structures of graphene in a polymer matrix by means of particle morphology represents an effective strategy for future composite engineering.

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Application of response surface methodology for thorium adsorption on PVA/Fe3O4/SiO2/APTES nanohybrid adsorbent

Cited by 90 publications

References 47 publications

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

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

A Mild and Facile Synthesis of Amino Functionalized CoFe2O4@SiO2 for Hg(II) Removal

Flexible free-standing composite films having 3D continuous structures of hollow graphene ellipsoids

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