Characterization and study of sorptive properties of differently prepared organoclays from a Brazilian natural bentonite

Vianna, Marilda Mendonça Guazzelli Ramos; Dweck, Jo; Kozievitch, Valquiria F.J.; Valenzuela‐Díaz, Francisco Rolando; Büchler, Pedro Maurício

doi:10.1007/s10973-005-0939-4

Cited by 27 publications

(8 citation statements)

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“…The carbon, nitrogen, and hydrogen analysis was used to quantify the organic contents in organo-clays and other organo-silicates [ 27 , 35 , 36 , 37 ]. The elemental analysis of the organo-magadiites is summarized in Table 1 .…”

Section: Resultsmentioning

confidence: 99%

Application of Organo-Magadiites for the Removal of Eosin Dye from Aqueous Solutions: Thermal Treatment and Regeneration

et al. 2018

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Na-magadiite exchanged with cetyl-trimethylammonium cations provided organophilic silicate materials that allowed for the effective removal of the acidic dye “eosin”. The organic cations were intercalated into the interlayer spacing of the layered silicate via an exchange reaction between the organic cations from their bromide salt and the solid Na-magadiite at room temperature. Different techniques were used to characterize the effect of the initial concentration of the surfactant on the structure of the organo-magadiites. The C, H, and N analysis indicated that a maximum of organic cations of 0.97 mmol/g was achieved and was accompanied by an expansion of the basal spacing of 3.08 nm, with a tilted angle of 59° to the silicate layers. The conformation of the organic surfactants was probed using solid-state 13C, finding mainly the trans conformation similar to that of the starting cetyl trimethylammonium bromide salt (C16TMABr). Thermal gravimetric analysis was carried out to study the thermal stability of the resulting organo-magadiites. The intercalated surfactants started to decompose at 200 °C, with a mass loss percentage of 8% to 25%, depending on the initial loading of the surfactant, and was accompanied by a decrease of the basal spacing from 3.16 nm to 2.51 nm, as deduced from the in situ X-ray diffraction studies. At temperatures below 220 °C, an expansion of the basal spacing from 3.15 to 3.34 nm occurred. These materials were used as a removal agent for the anionic dye eosin. The maximum amount of the dye removed was related to the organic cation content and to the initial concentration of eosin, with an improvement from 2.5 mg/g to 80.65 mg/g. This value decreased when the organo-magadiite was preheated at temperatures above 200 °C. The regeneration tests indicated that an 85% removal efficiency was maintained after six cycles of use for the organo-magadiite using Ci of 200 mg/L.

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Section: Resultsmentioning

confidence: 99%

Application of Organo-Magadiites for the Removal of Eosin Dye from Aqueous Solutions: Thermal Treatment and Regeneration

et al. 2018

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“…Adsorption process is one of the prominent treatment options for the removal of these pollutants from the aqueous mediums because it is possible to recover the adsorbent and adsorbate [4,7]. Many adsorbents including activated carbon [8,9], carbon nanotube [2,10], macroreticular resins [7], diatomite [1,4,5], and organoclay [11][12][13][14][15][16][17] have been used for adsorption of BTEX from aqueous solutions. Activated carbon is the most common material used extensively as an adsorbent for this purpose [9]; however, it is expensive and the regeneration cost is high [8,18].…”

Section: Introductionmentioning

confidence: 99%

“…Hence, the modi�cation of clay by a surfactant, especially the cationic type, shis it from the hydrophilic nature to the organophilic one [23]. Many studies have been conducted by other researchers for the removal of BTEX with clay modi�ed by cationic surfactants [11][12][13][14][15][16][17]. However, to the authors knowledge modi�cation of clay with tetradecyl trimethyl ammonium bromide (TTAB) as a cationic surfactant has not been investigated.…”

Section: Introductionmentioning

confidence: 99%

Multi‐Component Adsorption of Benzene, Toluene, Ethylbenzene, and Xylene from Aqueous Solutions by Montmorillonite Modified with Tetradecyl Trimethyl Ammonium Bromide

Nourmoradi¹,

Khiadani

Nikaeen³

2012

Journal of Chemistry

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Multicomponent adsorption of benzene, toluene, ethylbenzene, and xylene (BTEX) was assessed in aqueous solutions by montmorillonite modified with tetradecyl trimethyl ammonium bromide (TTAB-Mt). Batch experiments were conducted to determine the influences of parameters including loading rates of surfactant, contact time, pH, adsorbate concentration, and temperature on the adsorption efficiency. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to determine the adsorbent properties. Results showed that the modification of the adsorbent via the surfactant causes structural changes of the adsorbent. It was found that the optimum adsorption condition achieves with the surfactant loading rate of 200% of the cation exchange capacity (CEC) of the adsorbent for a period of 24 h. The sorption of BTEX by TTAB-Mt was in the order ofB<T<E<X. The experimental data were fitted by many kinetic and isotherm models. The results also showed that the pseudo-second-order kinetic model and Freundlich isotherm model could, respectively, be fitted to the experimental data better than other available kinetic and isotherm models. The thermodynamic study indicated that the sorption of BTEX with TTAB-Mt was achieved spontaneously and the adsorption process was endothermic as well as physical in nature. The regeneration results of the adsorbent also showed that the adsorption capacity of adsorbent after one use was 51% to 70% of original TTAB-Mt.

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“…The CHN elemental provides an estimation of the uptake of organic cations in the prepared organoclays [33,53,54,55,56,57]. The data are summarized in Table 1.…”

Section: Resultsmentioning

confidence: 99%

“…These data implied that intercalated C 16 cations were difficult to exchange either by Na cations or by protons [64,65]. These data were different when the intercalated cations were located between other layered silicates such as magadiite and kenyates [54,65]. This difference could be related to the different orientations of the intercalated surfactant cations in the interlayer spacing.…”

Section: Resultsmentioning

confidence: 99%

Eosin Removal by Cetyl Trimethylammonium-Cloisites: Influence of the Surfactant Solution Type and Regeneration Properties

et al. 2019

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The effect of the counteranion of hexadecyltrimethylammonium salts on the physico-chemical properties of organoclays was investigated, using a selected natural clay mineral with a cation exchange capacity of 95 meq/100 g. The uptake amount of C16 cations was dependent on the hexadecyltrimethylammonium (C16) salt solution used, the organoclay prepared from C16Br salt solution exhibited a value of 1. 05 mmole/g higher than those prepared from C16Cl and C16OH salt solutions. The basal spacing of these organoclays was in the range of 1.81 nm to 2.10 nm, indicating a similar orientation of the intercalated surfactants, and could indicated that the excess amount of surfactants, above the cation exchange capacity of 0.95 meq/g could be adsorbed on the external surface of the clay mineral sheets. These organoclays were found to be stable in neutral, acidic, and basic media. The thermal stability of these organoclays was carried out using thermogravimetric analysis and in-situ X-ray diffraction (XRD) techniques. The decomposition of the surfactant occurred at a maximum temperature of 240 °C, accompanied with a decrease of the basal spacing value close to 1.42 nm. The application of these organoclays was investigated to remove an acidic dye, eosin. The removal amount was related to the initial used concentrations, the amount of the surfactants contents, and to the preheated temperatures of the organoclays. The removal was found to be endothermic process with a maximum amount of 55 mg of eosin/g of organoclay. The value decreased to 25 mg/g, when the intercalated surfactants were decomposed. The reuse of these organoclays was limited to four regeneration recycles with a reduction of 20 to 30%. However, noticeable reduction between 35% to 50% of the initial efficiency, was achieved after the fifth cycle, depending of the used organoclays.

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Characterization and study of sorptive properties of differently prepared organoclays from a Brazilian natural bentonite

Cited by 27 publications

References 0 publications

Application of Organo-Magadiites for the Removal of Eosin Dye from Aqueous Solutions: Thermal Treatment and Regeneration

Application of Organo-Magadiites for the Removal of Eosin Dye from Aqueous Solutions: Thermal Treatment and Regeneration

Multi‐Component Adsorption of Benzene, Toluene, Ethylbenzene, and Xylene from Aqueous Solutions by Montmorillonite Modified with Tetradecyl Trimethyl Ammonium Bromide

Eosin Removal by Cetyl Trimethylammonium-Cloisites: Influence of the Surfactant Solution Type and Regeneration Properties

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