Treatment of Cr(VI) in aqueous solution by Ni–Al and Co–Al layered double hydroxides: Equilibrium and kinetic studies

Kameda, Tomohito; Kondo, Eisuke; Yoshioka, Toshiaki

doi:10.1016/j.jwpe.2014.12.001

Cited by 19 publications

(8 citation statements)

References 20 publications

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“…Figure 2b displayed the XRD patterns of NiAl-LDHs, Fe 0 , and Fe@NiAl-LDHs. For NiAl-LDHs, four evident diffraction peaks at about 2θ = 11.3°, 23.2°, 35.5°, and 61.7° were similar to a previous report [52]. As Fe 0 was concerned, three obvious diffraction peaks were at about 2θ = 44.8°, 65.2°, and 82.7°, which was quite consistent with a previous study [51].…”

Section: Resultssupporting

confidence: 91%

Determination of Sudan red contaminants at trace level from water samples by magnetic solid-phase extraction using Fe@NiAl-layered double hydroxide coupled with HPLC

Zhou

Yuan

et al. 2019

Environ Sci Eur

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Background: Sudan red dyes are widely used as color additions in various fields. Due to their potential carcinogenicity and large consumption, they have absorbed much more attention and become a research hot topic. There have been a few of existing methods for their analysis from samples; however, it is of great importance to develop simple, sensitive, and low-cost analytical method for public health and safety. This article described a new method based on magnetic Fe@NiAl-layered double hydroxides for enrichment of Sudan red dyes in combination with high-performance liquid chromatography. Results: The as-prepared magnetic Fe@NiAl-layered double hydroxides (Fe@NiAl-LDHs) exhibited good adsorption capacity for Sudan red dyes, and could be used as an effective adsorbent for preconcentration of three Sudan Red dyes from environmental water samples. The proposed method provided low limits of detection in the range of 0.002-0.005 μg L −1 with magnetic solid-phase extraction in combination with high-performance liquid chromatography. Conclusion: The developed method utilized the easy to prepare magnetic materials as adsorbents and conventional analytical instrument and provided high sensitivity, which provided a robust and low consumption of toxic organic solvent alternative method. The results of present study are of great value for interested laboratories to monitor the level of Sudan red dyes in water samples or develop sensitive determination methods to monitor other pollutants at trace level in environmental waters.

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Section: Resultssupporting

confidence: 91%

Determination of Sudan red contaminants at trace level from water samples by magnetic solid-phase extraction using Fe@NiAl-layered double hydroxide coupled with HPLC

Zhou

Yuan

et al. 2019

Environ Sci Eur

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“…exchange mechanism between the guest Cr(VI) anions and the host Cl − anions in the interlayer region of LDH has been highlighted by many scholars [25,32,54].…”

Section: Distribution Of Cr(vi) Species In Solutionmentioning

confidence: 99%

Adsorption mechanism of hexavalent chromium onto layered double hydroxides-based adsorbents: A systematic in-depth review

Tran

Nguyễn

et al. 2019

Journal of Hazardous Materials

198

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An attempt has been made in this review to provide some insights into the possible adsorption mechanisms of hexavalent chromium onto layered double hydroxides-based adsorbents by critically examining the past and present literature. Layered double hydroxides (LDH) nanomaterials are typical dual-electronic adsorbents because they exhibit positively charged external surfaces and abundant interlayer anions. A high positive zeta potential value indicates that LDH has a high affinity to Cr(VI) anions in solution through electrostatic attraction. The host interlayer anions (i.e., Cl -, NO3 -, SO4 2-, and CO3 2-) provide a high anion exchange capacity (53-520 meq/100g) which is expected to have an excellent exchangeable capacity to Cr(VI) oxyanions in water. Regarding the adsorptioncoupled reduction mechanism, when Cr(VI) anions make contact with the electron-donor groups in the LDH, they are partly reduced to Cr(III) cations. The reduced Cr(III) cations are then adsorbed by LDH via numerous interactions, such as isomorphic substitution and complexation. Nonetheless, the adsorption-coupled reduction mechanism is greatly dependent on: (1) the nature of divalent and trivalent salts utilized in LDH preparation, and (2) the types of interlayer anions (i.e., guest intercalated organic anions). The low Brunauer-Emmett-Teller specific surface area of LDH (1.80-179 m 2 /g) suggests that pore filling played an insignificant role in Cr(VI) adsorption. The Langmuir maximum adsorption capacity of LDH (Q o max) toward Cr(VI) was significantly affected by the used inorganic salt natures and synthetic methods of LDH. The Q o max values range from 16.3 mg/g to 726 mg/g. Almost all adsorption processes of Cr(VI) by LDH-based adsorbent occur spontaneously (∆G° <0) and endothermically (∆H° >0) and increase the randomness (∆S° >0) in the system. Thus LDH has much potential as a material that can effectively remove anion pollutants, especially Cr(VI) anions in industrial wastewater.

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“…Two different mechanisms of the ion release from LDH framework were described in the literature: − weathering and ion exchange. In the case of weathering, the partial dissolution of the LDH framework in aggressive medias defines the release of an entrapped ion. , The preferential dissolution of Al(III) from the Zn 2 Al/-LDH framework at alkaline pH can alter the charge balance and, hence, decrease the positive charge of the layers and decrease the amount of the intercalated anions enhancing MoO 4 2– release.…”

Section: Discussionmentioning

confidence: 99%

“…The partial substitution of a divalent cation by a trivalent into the brucite layer produces an excess of positive charge resulting in the presence of interleaved anions, some of which could be active corrosion inhibitors. Entrapped anions can be released from an LDH due to a dissolution of the LDH framework at extreme pH values , or due to an anion exchange within the LDH framework. − The ion exchange rate depends on the ion charge. ,, Monovalent ions such as Cl – and NO 3 – into Mg 2 Al/-LDH can be easily replaced by divalent ions such as CrO 4 2– , SO 4 2– , and CO 3 2– . However, this approximation should be applied with caution because of possible steric effects.…”

Section: Introductionmentioning

confidence: 99%

Factors Affecting MoO₄^2– Inhibitor Release from Zn₂Al Based Layered Double Hydroxide and Their Implication in Protecting Hot Dip Galvanized Steel by Means of Organic Coatings

Shkirskiy

Keil

Hintze-Bruening

et al. 2015

ACS Appl. Mater. Interfaces

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Zn2Al/-layered double hydroxide (LDH) with intercalated MoO4(2-) was investigated as a potential source of soluble molybdate inhibitor in anticorrosion coatings for hot dip galvanized steel (HDG). The effect of solution pH, soluble chlorides, and carbonates on the release kinetics of the interleaved MoO4(2-) ions from the LDH powder immersed in solutions containing different anions was studied by X-ray diffraction, in situ attenuated total reflectance infrared (ATR-IR) spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The effect of the solution composition on the total release and the release kinetics was demonstrated. Less than 30% of the total amount of the intercalated MoO4(2-) was released after 24 h of the immersion in neutral 0.005-0.5 M NaCl and 0.1 M NaNO3 solutions whereas the complete release of MoO4(2-) was observed after 1 h in 0.1 M NaHCO3 or Na2SO4 and in alkaline solutions. The in situ ATR-IR experiments and quantification of the released soluble species by ICP-AES demonstrated the release by an anion exchange in neutral solutions and by the dissolution of Zn2Al/-LDH in alkaline solutions. The anion exchange kinetics with monovalent anions was described by the reaction order n = 0.35 ± 0.05 suggesting the diffusion control; for divalent anions, n = 0.70 ± 0.06 suggested the control by a surface reaction. Dissolution of Zn from coated HDG with and without Zn2Al/-MoO4(2-) fillers, leaching of MoO4(2-) from the coating, and the electrochemical impedance spectroscopy response of the coated systems were measured during the immersion in 0.5 M NaCl solutions with and without 0.1 M NaHCO3. Without carbonates, the release of soluble MoO4(2-) was delayed for 24 h with no inhibiting effect whereas with 0.1 M NaHCO3 the immediate release was accompanied by the immediate and strong inhibiting effect on Zn dissolution. The concept of controlling the inhibition performance of LDH hybrid coatings by means of the environment composition is discussed.

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Treatment of Cr(VI) in aqueous solution by Ni–Al and Co–Al layered double hydroxides: Equilibrium and kinetic studies

Cited by 19 publications

References 20 publications

Determination of Sudan red contaminants at trace level from water samples by magnetic solid-phase extraction using Fe@NiAl-layered double hydroxide coupled with HPLC

Determination of Sudan red contaminants at trace level from water samples by magnetic solid-phase extraction using Fe@NiAl-layered double hydroxide coupled with HPLC

Adsorption mechanism of hexavalent chromium onto layered double hydroxides-based adsorbents: A systematic in-depth review

Factors Affecting MoO₄^2– Inhibitor Release from Zn₂Al Based Layered Double Hydroxide and Their Implication in Protecting Hot Dip Galvanized Steel by Means of Organic Coatings

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Treatment of Cr(VI) in aqueous solution by Ni–Al and Co–Al layered double hydroxides: Equilibrium and kinetic studies

Cited by 19 publications

References 20 publications

Determination of Sudan red contaminants at trace level from water samples by magnetic solid-phase extraction using Fe@NiAl-layered double hydroxide coupled with HPLC

Determination of Sudan red contaminants at trace level from water samples by magnetic solid-phase extraction using Fe@NiAl-layered double hydroxide coupled with HPLC

Adsorption mechanism of hexavalent chromium onto layered double hydroxides-based adsorbents: A systematic in-depth review

Factors Affecting MoO42– Inhibitor Release from Zn2Al Based Layered Double Hydroxide and Their Implication in Protecting Hot Dip Galvanized Steel by Means of Organic Coatings

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Factors Affecting MoO₄^2– Inhibitor Release from Zn₂Al Based Layered Double Hydroxide and Their Implication in Protecting Hot Dip Galvanized Steel by Means of Organic Coatings