Cr(VI) Removal from Aqueous by Adsorption on Amine-Functionalized Mesoporous Silica Prepared from Silica Fume

Li, Xitong; Han, Cuiping; Zhu, Wenjie; Ma, Wenhui; Luo, Yongming; Zhou, Yang; Yu, Jianguo; Wei, Kuixian

doi:10.1155/2014/765856

Cited by 25 publications

(18 citation statements)

References 23 publications

(22 reference statements)

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“…Especially, the content of -NH 3 + is proportional to the adsorption amount of Cr(VI) by considering the XPS and Cr removal experiments. Several studies have reported that anionic Cr(VI) is adsorbed by NH 3 + groups via electrostatic interaction 14 , 32 , 33 .…”

Section: Resultsmentioning

confidence: 99%

Investigation of the mechanism of chromium removal in (3-aminopropyl)trimethoxysilane functionalized mesoporous silica

Lee

Kim

Choi

et al. 2018

Sci Rep

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We are proposed that a possible mechanism for Cr(VI) removal by functionalized mesoporous silica. Mesoporous silica was functionalized with (3-aminopropyl)trimethoxysilane (APTMS) using the post-synthesis grafting method. The synthesized materials were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 adsorption-desorption analysis, Fourier-transform infrared (FT-IR), thermogravimetric analyses (TGA), and X-ray photoelectron spectroscopy (XPS) to confirm the pore structure and functionalization of amine groups, and were subsequently used as adsorbents for the removal of Cr(VI) from aqueous solution. As the concentration of APTMS increases from 0.01 M to 0.25 M, the surface area of mesoporous silica decreases from 857.9 m2/g to 402.6 m2/g. In contrast, Cr(VI) uptake increases from 36.95 mg/g to 83.50 mg/g. This indicates that the enhanced Cr(VI) removal was primarily due to the activity of functional groups. It is thought that the optimum concentration of APTMS for functionalization is approximately 0.05 M. According to XPS data, NH3+ and protonated NH2 from APTMS adsorbed anionic Cr(VI) by electrostatic interaction and changed the solution pH. Equilibrium data are well fitted by Temkin and Sips isotherms. This research shows promising results for the application of amino functionalized mesoporous silica as an adsorbent to removal Cr(VI) from aqueous solution.

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Section: Resultsmentioning

confidence: 99%

Investigation of the mechanism of chromium removal in (3-aminopropyl)trimethoxysilane functionalized mesoporous silica

Lee

Kim

Choi

et al. 2018

Sci Rep

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show abstract

“…The molecular structure of composites was investigated by FTIR technique. Figure 1 [54]. In comparison to the MCM-41 spectrum, the spectrum of MCM-41-CIP presented additional bands at 1715 cm −1 , 1494 cm −1 , and 1459 cm −1 , which were also observed in the spectrum of freeze-dried CIP confirming the drug adsorption onto the MCM-41.…”

Section: Molecular Structurementioning

confidence: 74%

Silica-Polymer Composites as the Novel Antibiotic Delivery Systems for Bone Tissue Infection

et al. 2019

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Bone tissue inflammation, osteomyelitis, is commonly caused by bacterial invasion and requires prolonged antibiotic therapy for weeks or months. Thus, the aim of this study was to develop novel silica-polymer local bone antibiotic delivery systems characterized by a sustained release of ciprofloxacin (CIP) which remain active against Staphylococcus aureus for a few weeks, and do not have a toxic effect towards human osteoblasts. Four formulations composed of ethylcellulose (EC), polydimethylsiloxane (PDMS), freeze-dried CIP, and CIP-adsorbed mesoporous silica materials (MCM-41-CIP) were prepared via solvent-evaporation blending method. All obtained composites were characterized in terms of molecular structure, morphological, and structural properties by using Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray diffraction (XRD), thermal stability by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and in vitro antibiotic release. The antibacterial activity against Staphylococcus aureus (ATCC 6538) as well as the in vitro cytocompatibility to human osteoblasts of obtained composites were also examined. Physicochemical results confirmed the presence of particular components (FTIR), formation of continuous polymer phase onto the surface of freeze-dried CIP or MCM-41-CIP (SEM/EDX), and semi-crystalline (composites containing freeze-dried CIP) or amorphous (composites containing MCM-41-CIP) structure (XRD). TGA and DSC analysis indicated the high thermal stability of CIP adsorbed onto the MCM-41, and higher after MCM-41-CIP coating with polymer blend. The release study revealed the significant reduction in initial burst of CIP for the composites which contained MCM-41-CIP instead of freeze-dried CIP. These composites were also characterized by the 30-day activity against S. aureus and the highest cytocompatibility to human osteoblasts in vitro.

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“… adsorbent q max /(mg g −1 ) pH initial concentration (mg l −1 ) ref. Fe(III)-CBs 166.3 6.0 20.0 this study γ-Fe 2 O 3 -chitosan beads 106.5 5.0 1000 [ 32 ] magnetic chitosan nanoparticles 55.8 3.0 180 [ 33 ] composite chitosan biosorbent 153.8 2.0 400 [ 18 ] ethylenediamine-modified cross-linked magnetic chitosan resin 51.8 2.0 100 [ 35 ] cross-linked chitosan-Fe(III) complex 148.4 4.8 380 [ 36 ] metal ion imprinted chitosan resin 76.9 5.5 100 [ 37 ] Fe 0 nanorods modified with chitosan 118.8 5.0 200 [ 15 ] zirconium cross-linked chitosan composite 175.0 5.0 30...…”

Section: Resultsmentioning

confidence: 99%

“…Among them, adsorption has been recognized as an economical and effective technique, and much attention has been paid to the development of cost-effective and efficient adsorbents [ 11 – 13 ]. Various adsorbents, such as active carbon [ 14 ], silica-gel [ 15 ], raw clays [ 16 ] and hydrotalcite [ 17 ], have been used for Cr(VI) adsorption. However, these adsorbents focused on treating industrial wastewater; although they had high adsorption capacities under acid pH, the treated water still had Cr(VI) anion, whose concentration was not low as expected, limiting their broad application.…”

Section: Introductionmentioning

confidence: 99%

“…Various adsorbents, such as active carbon [14], silica-gel [15], raw clays [16] and hydrotalcite [17], have been used for Cr(VI) adsorption. However, these adsorbents focused on treating industrial wastewater; although they had high adsorption capacities under acid pH, the treated water still had Cr(VI) anion, whose concentration was not low as expected, limiting their broad application.…”

Section: Introductionmentioning

confidence: 99%

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An exploratory study on low-concentration hexavalent chromium adsorption by Fe(III)-cross-linked chitosan beads

Wu¹,

Zhang²,

Jin³

et al. 2017

R. Soc. open sci.

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In this study, Fe(III)-cross-linked chitosan beads (Fe(III)-CBs) were synthesized and employed to explore the characteristics and primary mechanism of their hexavalent chromium (Cr(VI)) adsorption under low concentration Cr(VI) (less than 20.0 mg l−1) and a pH range from 2.0 to 8.0. Batch tests were conducted to determine the Cr(VI) adsorption capacity and kinetics, and the effects of pH and temperature on the adsorption under low concentration Cr(VI) and a pH range from 2.0 to 8.0. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were employed to explore the characteristics of Fe(III)-CBs and their Cr(VI) adsorption mechanisms. The results show that, unlike the adsorption of other absorbents, the Cr(VI) adsorption was efficient in a wide pH range from 2.0 to 6.0, and well described by the pseudo-first-order model and the Langmuir–Freundlich isotherm model. The capacity of Cr(VI) adsorption by Fe(III)-CBs was as high as 166.3 mg g−1 under temperature 25°C and pH 6.0. The desorption test was also carried out by 0.1 mol l−1 NaOH solution for Fe(III)-CBs regeneration. It was found that Fe(III)-CBs could be re-used for five adsorption–desorption cycles without significant decrease in Cr(VI) adsorption capacity. Ion exchange was confirmed between functional groups (i.e. amino group) and Cr(VI) anions (i.e. CrO42−). The amino-like functional groups played a key role in Cr(VI) distribution on the Fe(III)-CBs surface; Cr(VI) adsorbed on Fe(III)-CBs was partially reduced to Cr(III) with alcoholic group served as electron donor, and then formed another rate-limiting factor. So, Fe(III)-CBs has a good prospect in purifying low concentration Cr(VI) water with a pH range from 2.0 to 6.0.

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Cr(VI) Removal from Aqueous by Adsorption on Amine-Functionalized Mesoporous Silica Prepared from Silica Fume

Cited by 25 publications

References 23 publications

Investigation of the mechanism of chromium removal in (3-aminopropyl)trimethoxysilane functionalized mesoporous silica

Investigation of the mechanism of chromium removal in (3-aminopropyl)trimethoxysilane functionalized mesoporous silica

Silica-Polymer Composites as the Novel Antibiotic Delivery Systems for Bone Tissue Infection

An exploratory study on low-concentration hexavalent chromium adsorption by Fe(III)-cross-linked chitosan beads

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