Effects of Acid Treatment on the SEM-EDX Characteristics of Kaolin Clay

Yahaya, Shehu; Jikan, Suzi Salwah; Badarulzaman, Nur Azam; Adamu, Ajiya Dahiru

doi:10.22178/pos.26-6

Cited by 15 publications

(4 citation statements)

References 14 publications

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“…Scanning electron microscopy Figure 6 shows the scanning electron micrographs of the material studied subjected to a 1 M sulfuric acid treatment (Sample S1). The sample is present in sheets form, showing that the activation process has partially destroyed the laminar arrangement of the material, as has been previously reported (Jeenpadiphat and Tungasmita 2014;Yahaya et al 2017). On the other hand, the observed morphology is consistent with the results obtained from the nitrogen adsorption-desorption isotherms, typical of laminar materials.…”

Section: Nitrogen Adsorption-desorption Isothermspotentiometric Titrasupporting

confidence: 78%

Study of structural properties of acid-treated natural sediment and its application as a sustainable catalyst

Reinoso

Angeletti

Cervellini

et al. 2020

Braz. J. Chem. Eng.

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This paper aims to characterize a natural sediment from Bahía Blanca estuary (Argentina) as a new clay source and determine the catalytic capacity after its structural modification by an acid activation process. The acid treatment was performed by employing H 2 SO 4 at different concentrations at 353 K and 60 min. The raw material and acid-activated samples were characterized by XRD, XRF, FTIR, N 2 physisorption, TGA, SEM, EDX, potentiometric titration and pyridine adsorption monitored by FTIR. Moreover, the catalytic activity on lauric acid esterification with methanol was evaluated as a test reaction. From the structural characterization, it was determined that the material studied contains mainly Ca-montmorillonite, illite, albite and quartz. Likewise, the results obtained showed that the acid-treatment impacts the material characteristics, predominantly surface acidity and textural properties. Particularly, it was evidenced that the samples treated under medium acid activation conditions lead to an increase in acid site number and strength and specific surface area and consequently improve the catalytic activity. The results obtained evidenced that this low cost and widely available raw material presents an interesting mineralogical composition with a high clay mineral content. Additionally, the catalytic performance showed a good conversion in the test reaction regarding other heterogeneous catalysts. Hence, considering these results, this natural sediment merits further research on its purification and application.

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Section: Nitrogen Adsorption-desorption Isothermspotentiometric Titrasupporting

confidence: 78%

Study of structural properties of acid-treated natural sediment and its application as a sustainable catalyst

Reinoso

Angeletti

Cervellini

et al. 2020

Braz. J. Chem. Eng.

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“…The images have unstructured in nature, irregular in shape with uneven edge agglomerate and porous in the surface. The raw kaolin, Figure 3 (a) validate the clay particles of the layered silicates in the form of books tells that the particles are not fully dispersed into individual layers [49,50]. From the raw kaolin, clear layered rectangular shapes observed an indication that natural kaolinite, without any treatment, is double layer alumino-silicate clay [51].…”

Section: Surface Morphology Examination Using Semmentioning

confidence: 95%

Synthesis and characterization of Ethiopian kaolin for the removal of basic yellow (BY 28) dye from aqueous solution as a potential adsorbent

Aragaw

Angerasa

2020

Heliyon

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In the present research, the kaolin adsorbents (beneficiated, raw powder, and calcined) were prepared from Ethiopian natural kaolin through mechanical, wet, and thermal processes. The geochemical and surface properties of kaolin adsorbent were characterized using FTIR, SEM/EDS, XRD, and XRF. In the batch experiment, basic operation parameters (initial dye concentrations, pH, temperature, contact time, and adsorbent dosage) were examined. Percentage removal efficiency basic yellow 28 (BY28) dye were recorded as 94.79%, 92.08%, and 87.08% onto beneficiated, raw, and calcined kaolin absorbents, respectively at an initial dye concentration of 20 mg/L, solution pH of 9, the temperature of 30 C C, and contact time of 60 min and adsorbent dosage of 1g/ 100L. The molar ratio of SiO 2 /Al 2 O 3 was recorded as 2.911 Percent mass composition of Ethiopian kaolin which is higher than the expected pure kaolinite standard which allows us to classify the kaolin clay as a siliceous one. The calculated values of ΔG 0 for beneficiated adsorbent are-1.243, 1.576, and 4.396 kJ/mol at 303.15, 323.15, and 343.15 K, respectively for 20 mg/L of dye concentration and solution pH of 9, suggests that the thermodynamic behavior at lowest temperature is more feasible and spontaneous as compared with the higher temperature one. A similar fashion was calculated for raw and calcined adsorbents. The negative values of ΔH o and ΔS suggest that the adsorption phenomenon is exothermic and the adsorbate molecules are organized on the solid phase in a more disordered fashion than the liquid phase. The pseudo-first-order and pseudo-second-order models have been used to describe the kinetics in the adsorption processes. The Pseudo-second-order model has been fitted for the BY 28 dye adsorption in the studied concentration range. The adsorption of BY 28 dye for raw and calcined adsorbents follows the Langmuir isotherm and the Freundlich isotherm fitted for the beneficiated adsorbent. The amount of BY28 dye taken up by beneficiated, raw, and calcined kaolin adsorbents was found as 1.896, 1.842, and 1.742 mg/g, respectively at a contact time of 1.0 h, the adsorbent dosage of 1.0 g, initial dye concentration ¼ 20 mg/L and solution pH ¼ 9 at 30 C. The results found that these raw and prepared local kaolin adsorbents have a capacity as low-cost alternatives for the removal of dyes in industrial wastewater.

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“…However, activation from natural kaolinite shows that improving the properties of kaolinite by chemical processes is difficult because of the high passivity of this material. Thus, it was not significantly affected by acidic or alkaline treatments, even under concentrated solution conditions [4][5][6][7].…”

Section: ■ Introductionmentioning

confidence: 91%

Preparation of Ammonia Dealuminated Metakaolinite and Its Adsorption against Bixin

et al. 2020

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This study aims to prepare dealuminated metakaolinite which has a high surface area by using NH4OH as an activator. The natural kaolinite sample was treated at 600 °C for 6 h in order to obtain metakaolinite. A dealuminated metakaolinite was then prepared by the repeated activation method using concentrated ammonia (5 M NH4OH) at room temperature. Depending on the nature of each type of material, natural kaolinite, NH4OH treated kaolinite, metakaolinite and NH4OH treated metakaolinite were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET-N2) measurements. XRD and FTIR results confirmed that structural transformation from kaolinite to metakaolinite had occurred. According to SEM-EDS data, the activation of metakaolinite by NH4OH allowed the dealumination of metakaolinite. The increase in the Si/Al ratio was almost twice as high as in kaolinite. BET-N2 analysis showed that the specific surface area and the total pore volume increased significantly after activation. Its adsorption properties were tested against bixin. Bixin adsorption on dealuminated metakaolinite followed pseudo-second order kinetic where k2 = 0.20 g/mg min. The adsorption isotherm followed the Langmuir model where qm = 0.72 mg/g.

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Effects of Acid Treatment on the SEM-EDX Characteristics of Kaolin Clay

Cited by 15 publications

References 14 publications

Study of structural properties of acid-treated natural sediment and its application as a sustainable catalyst

Study of structural properties of acid-treated natural sediment and its application as a sustainable catalyst

Synthesis and characterization of Ethiopian kaolin for the removal of basic yellow (BY 28) dye from aqueous solution as a potential adsorbent

Preparation of Ammonia Dealuminated Metakaolinite and Its Adsorption against Bixin

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