Acid treatments of montmorillonite-rich clay for Fe removal using a factorial design method

Bieseki, Lindiane; Bertell, Francine; Treichel, Helen; Penha, Fábio G.; Pergher, Sibele B. C.

doi:10.1590/s1516-14392013005000114

Cited by 40 publications

(17 citation statements)

References 17 publications

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“…The occurrence of these reactions of decationating and dealumination is confirmed by changes in the chemical composition of natural aluminosilicate samples ( Moreover, due to changes of the chemical composition caused by acid treatment, serious variations of surface and structural characteristics of minerals have been observed [32,33], which also strongly depend on the acid solution concentration and duration of the treatment. At shorter acid leaching times, mainly Ion-exchange reactions take place along with a slight destruction of the layered structure.…”

Section: Chemical Modification Of Clay Minerals and Its Influence On mentioning

confidence: 91%

Adsorption of Industrial Pollutants by Natural and Modified Aluminosilicates

Novikova¹,

Belchinskaya²

2016

Clays, Clay Minerals and Ceramic Materials Based on Clay Minerals

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The adsorption ability of natural clay minerals and zeolites is a structurally caused distinguished feature, which determines their physical-chemical properties and almost each area of application. The type of surface active sites responsible for adsorption behavior differs for various structural types of aluminosilicates and varies under modifying agents. The present chapter illustrates the effect of the acid and base modification of natural aluminosilicates on their adsorption behavior in respect to a number of pollutants present in aqueous media. For this, the change of adsorption-structural characteristics of natural clay samples containing representatives of the main groups of clay minerals under activation is considered. Further, the chapter focuses on characterization of surface active sites by means of a new method of a catalytic conversion of 2-methylbut-3-yn-2-ol. The presence of both acid and basic sites on the aluminosilicates surface as well as variations of surface acidity and basicity for different structural types of aluminosilicates under varying conditions of modification is discussed. The third highlight of the chapter encompasses adsorption processes taking place in aqueous solutions of formaldehyde, acetic acid, and ammonium chloride on the surface of natural and activated aluminosilicates. The activating effect of a number of inorganic acids and bases on adsorption equilibrium is compared. The considered mechanism of the adsorption of electrolytes and polar molecules from aqueous media may comprise hydrogen bonding, chemisorptions, or ion-exchange reactions.

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Section: Chemical Modification Of Clay Minerals and Its Influence On mentioning

confidence: 91%

Adsorption of Industrial Pollutants by Natural and Modified Aluminosilicates

Novikova¹,

Belchinskaya²

2016

Clays, Clay Minerals and Ceramic Materials Based on Clay Minerals

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“…The nitrogen adsorption/ desorption isotherms of montmorillonite as shown in Fig. 16 The hysteresis was not observed initially and it occurred only in the high relative pressure range.…”

Section: Ft-ir and N 2 Adsorption Isothermsmentioning

confidence: 99%

The influence of structural and processing parameters of modifiers on the interlayer structure of modified montmorillonite

Chen

Thirumavalavan

et al. 2015

RSC Adv.

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This study mainly focused on exploring the influence of different processing methods on the structure, physical and chemical characteristics and adsorption ability of modified montmorillonites. The effect of three different modifiers with different chain lengths such as 12-aminododecanoic acid (ADA), 1,12diaminododecane (DDC) and octadecylamine (ODC) on the d-spacing of montmorillonite was studied in detail. FT-IR spectra and N 2 adsorption isotherms were used to confirm the formation of modified montmorillonites. XRD experiments were carried out and the influence of structural and processing parameters of the modifiers on the interlamellar spacing of modified montmorillonites was studied. It was found that the ODC modifier with a longer carbon chain comparatively enhanced the interlamellar spacing than that of other modifiers. The influence of HCl, the amount of modifiers and temperature on the interlayer structure was also discussed. Upon modification, the peak around 2q ¼ 6.8 due to [001] plan was shifted to lower 2q values and the corresponding interlamellar spacing was increased from 1.39 nm to 2.97 nm. The adsorption behavior of the modified montmorillonites for both inorganic and organic pollutants was also discussed based on structural and surface properties. The observed log K OM values for the distribution of organic pollutants onto modified montmorillonites are comparatively larger in this study indicating that these modified montmorillonites are superior to both natural soil systems as well as literature studies reported so far.

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“…To improve these properties, several trails were done including mechano-chemical activation [5] intercalate with some organic materials and thermo-chemical routs or chemical activation. Acid activation is the more familiar methods for modification of the kaolin materials which involves the leaching of the kaolin ore with the minerals acids [6][7][8][9][10][11][12][13]. Most of the acid treatment has indicated that the kaolin is more soluble in H 2 SO 4 than the other acids.…”

Section: Modification Of Kaolinmentioning

confidence: 99%

Studies on the effects of kaolin and modified kaolin on the flamability of APP/PP system.

et al. 2017

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HIS WORK is a continuation of the previous works by the authors to increase the efficiency of ammonium polyphosphate (APP) as flame retardant for polypropylene (PP). In this work a more abundant kaolin was used. Also to improve the efficiency of kaolin, an acid modification by sulfuric acid was used. XRD, XRF, IR, SEM and BET were used to characterization the samples. TGA and DTA were used to evaluate the prepared samples as flame retardant. For comparison, five samples of (APP/ Kaolin ore)/PP were prepared and other five samples (APP/Modified kaolin)/PP have the same composition also were prepared. The analysis of the XRD, IR and SEM results indicate that the acid treatment of kaolin increases the SiO 2 content which lead to increase the surface area. In the same time the acid leaching causes some distortion in the crystalline and the layers. The evaluation of the flammability of the system by using the TGA indicate that the presence of kaolin increases the time of degradation of PP. On other hand, the modification of kaolin by sulfuric acid improves the role of the kaolin when added to the APP.

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Acid treatments of montmorillonite-rich clay for Fe removal using a factorial design method

Cited by 40 publications

References 17 publications

Adsorption of Industrial Pollutants by Natural and Modified Aluminosilicates

Adsorption of Industrial Pollutants by Natural and Modified Aluminosilicates

The influence of structural and processing parameters of modifiers on the interlayer structure of modified montmorillonite

Studies on the effects of kaolin and modified kaolin on the flamability of APP/PP system.

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