Bentonite modification with hexadecylpyridinium and aluminum polyoxy cations and its effectiveness in Se(IV) removal

Oruçoğlu, Esra; Haciyakupoglu, Sevilay

doi:10.1016/j.jenvman.2015.06.005

Cited by 18 publications

(13 citation statements)

References 62 publications

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“…15,29,[33][34][35] In the current work, the unmodified MMt has a d-spacing of 1.23 nm, which expanded when the intercalated ions were exchanged with surfactants small particle size, smooth and micro-porous surface with fluffy appearance due to the closely packed flakes. The BET surface area of unmodified MMt clay was found to be 58 m /g for HDT-MA and HDPy surfactant respectively.…”

Section: Xrdmentioning

confidence: 76%

“…This is consistent with the previously reported studies. 34,40 This corresponds to 7 to 8% mass loss for both clays, which indicates the surfactant loading to the clays is not very efficient. The last stage shows that besides degradation of Al, Si-polyoxy cations, dehydroxylation of structural hydroxyl unit in clay in the octahedral layer of montmorillonite also takes place.…”

Section: 5 Tgamentioning

confidence: 99%

“…34,47 The influence of initial dye concentrations was examined using 0.1g of the HDPy and HDTMA-organoclays at pH 7 with equilibrium time of 60 minutes. Figure 7 shows that adsorption of dyes onto organoclays increases with the increase in the concentration of dyes in a solution up to a certain value after which it levelled off.…”

Section: Effect Of Initial Dye Concentrationmentioning

confidence: 99%

“…As depicted by the Figure 6 that adsorption of both dyes onto the organoclays increases with the increase of contact time, which is consistent with the previous studies. 14,29,34 At first, the adsorption of dyes occurs through boundary layer adsorption and the adsorptions rates were high because of the accessibility of the higher surface area for the rapid attachment of these dyes to the external exposed surfaces of the organoclays and backs off step by step in the dye onto the organoclay shows opposite trends by varying the concentration of dye solution. Several researchers also found the same adsorption results as function of MB and MG dye concentration.…”

Section: 2 Effect Of Timementioning

confidence: 99%

“…Several researchers also found the same adsorption results as function of MB and MG dye concentration. 28,34,45,47,51 The inverse patterns for the adsorption capacity and percent removal can be clarified with the way that: there are fixed number of binding sites on the organoclay surface. At the point when the dyes are available in little concentration, the adsorption will be fast and the percent removal of dyes will be high because of the higher number of accessible sites on the surface of organoclays.…”

Section: 2 Effect Of Timementioning

confidence: 99%

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Adsorption Kinetics of Malachite Green and Methylene Blue from Aqueous Solutions Using Surfactant-modified Organoclays

Ullah

Nafees²,

Iqbal

et al. 2017

ACSi

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The main objective of this research is to study the adsorption behaviour of malachite green and methylene blue dyes onto the surfactant modified natural clays. The results of SEM, XRD, IR, and thermal analysis confirms the intercalation of organic moiety in to the clay. The adsorption results show that pseudo-first order kinetics best fitted for both the dyes adsorbed on organo-clay. The data also reveals that both dyes are in a good agreement with Langmuir isotherm in both types of modified clays. The value of separation factor, R L , from Langmuir equation and Freundlich constant, n, give an indication of favourable adsorption. The maximum adsorption capacity q m based on Langmuir model was found to be 294-303 mg/g at 25 °C, is in good agreement with the experimental values.

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Section: Xrdmentioning

confidence: 76%

Section: 5 Tgamentioning

confidence: 99%

Section: Effect Of Initial Dye Concentrationmentioning

confidence: 99%

Section: 2 Effect Of Timementioning

confidence: 99%

Section: 2 Effect Of Timementioning

confidence: 99%

See 3 more Smart Citations

Adsorption Kinetics of Malachite Green and Methylene Blue from Aqueous Solutions Using Surfactant-modified Organoclays

Ullah

Nafees²,

Iqbal

et al. 2017

ACSi

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Purification of Turkish Bentonites and Investigation of the Contact Angle, Surface Free Energy and Zeta Potential Profiles of Organo-Bentonites as a Function of CTAB Concentration

Çiftçi

Ersoy

Evcin

2020

Clays and clay miner.

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Purification of raw bentonites and organo-bentonite preparations is sometimes required for industrial use. Zeta (electrokinetic) potential (ζ), contact angle (wettability/hydrophobicity), and surface free energy (SFE) are important surface characteristics and vary significantly according to the applied surfactant concentration when preparing organo-bentonite. Changes in these characteristics determine the stability, behavior, and efficiency of organo-bentonites in various applications such as adsorption, composite materials, and drug-delivery systems. Knowing how much surfactant should be used to prepare organo-bentonite is, therefore, critical. The purpose of the present study was to determine the effect of concentration of the cationic surfactant cetyltrimethylammonium bromide (CTAB) adsorbed in organo-bentonite (prepared from two local and commercial raw bentonites with potential for use in adsorbent and composite materials) on the ζ potential, contact angle, and SFE profiles. The raw bentonites were purified using sedimentation and centrifugation techniques prior to preparation of the organo-bentonite. The purification results were evaluated in light of X-ray diffraction (XRD), cation exchange capacity (CEC), free swelling volume (FSV), X-ray fluorescence (XRF), and particle-size analysis data. Most of the gangue minerals (feldspar, calcite, clinoptilolite, opal, quartz, and mica) having particle size >5 μm were removed from the raw bentonites by using a one-stage sedimentation or a Falcon gravity separator (FGS). Higher yields (68.8% and 81.3% for two bentonites) were obtained with the FGS compared to sedimentation while purification levels were almost the same. ζ changed greatly from –35 mV (and –40 mV) toward 38 mV (and 40 mV) with increasing CTAB concentrations. Similar profiles were also obtained for wettability; maximum contact angles for organo-bentonites were measured as ~72–73o, while they were 12.65 and 14.1o for two purified and unmodified bentonites. SFEs were calculated using contact-angle data, and decreased to minimum values of 41.5–43.6 mJ/m2 from 78.6–78.2 mJ/m2 upon treatment of raw bentonites with CTAB. 100–130% CEC concentration was sufficient to prepare organo-bentonites with maximum hydrophobicity and positively charged surfaces.

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Hexadecylpyridinium (HDPy) modified bentonite for efficient and selective removal of 99Tc from wastewater

Yang

Shi

Gao

et al. 2020

Chemical Engineering Journal

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Bentonite modification with hexadecylpyridinium and aluminum polyoxy cations and its effectiveness in Se(IV) removal

Cited by 18 publications

References 62 publications

Adsorption Kinetics of Malachite Green and Methylene Blue from Aqueous Solutions Using Surfactant-modified Organoclays

Adsorption Kinetics of Malachite Green and Methylene Blue from Aqueous Solutions Using Surfactant-modified Organoclays

Purification of Turkish Bentonites and Investigation of the Contact Angle, Surface Free Energy and Zeta Potential Profiles of Organo-Bentonites as a Function of CTAB Concentration

Hexadecylpyridinium (HDPy) modified bentonite for efficient and selective removal of 99Tc from wastewater

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