Effect of acid activation of palygorskite on their toluene adsorption behaviors

Zhu, Jianxi; Zhang, Ping; Wang, Yuebo; Wen, Ke; Su, Xiaoli; Zhu, Runliang; He, Hongping; Xi, Yunfei

doi:10.1016/j.clay.2017.07.019

Cited by 89 publications

(41 citation statements)

References 44 publications

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“…Adsorbent material can be reused, applied to various pollutants, and be used in water treatment in a broad range of dye concentrations [28][29][30]. However, some adsorbent materials can present a high cost, especially notable in emerging countries, such as activated carbon [31,32]. This motivated the search for alternative low-cost and efficient adsorbents for the treatment of waters.…”

Section: Introductionmentioning

confidence: 99%

Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water

et al. 2021

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The effect of acid treatment on the adsorptive capacity of a Brazilian palygorskite to remove the crystal violet (CV) and congo red (CR) dyes was investigated. The raw palygorskite was acid-treated by different HCl solutions (2, 4, and 6 mol/L). The modifications on the palygorskite structure were investigated using X-ray diffraction, X-ray fluorescence, Fourier-transform infrared spectroscopy, N2 adsorption/desorption, and thermogravimetric and differential thermal analysis. The efficiency of CV and CR adsorption was investigated, and the effect of the initial concentration, contact time, pH, and adsorbent amount was analyzed. The results revealed that CV adsorption in the acid-treated palygorskite was higher than that of the raw material. A Langmuir isotherm model was observed for the adsorption behavior of CV, while a Freundlich isotherm model was verified for the CR adsorption. A pseudo-second-order model was observed for the adsorption kinetics of both dyes. The higher CV adsorption capacity was observed at basic pH, higher than 97%, and the higher CR removal was observed at acidic pH, higher than 50%. The adsorption parameters of enthalpy (ΔH), entropy (ΔS), and Gibbs energy (ΔG) were evaluated. The adsorption process of the CV and CR dyes on the raw and acid-treated Brazilian palygorskite was predominantly endothermic and occurred spontaneously. The studied raw palygorskite has a mild-adsorption capacity to remove anionic dyes, while acid-treated samples effectively remove cationic dyes.

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Section: Introductionmentioning

confidence: 99%

Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water

et al. 2021

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“…Among the various types of clays, bentonite is more popular. Its physicochemical and adsorption properties depend on the montmorillonite content, the crystalline structure of the clay minerals that constitute them and the nature of the inter-layer cations [8,9]. In order to eliminate impurities and different exchangeable cations from clay minerals and to prepare a well-defined material for use as catalyst and adsorbent, various activations have been used, most often with inorganic acids [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Effect of Structure and Chemical Activation on the Adsorption Properties of Green Clay Minerals for the Removal of Cationic Dye

et al. 2018

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In this study, natural clay minerals with green appearance were treated with sulfuric acid. Mass percentage of acid (wt%), temperature (T), contact time (t) and liquid-to-solid mass ratio (R) are used as the prevailing factors that determine the extent of acid-activation. The values of these factors range from 15–50%, 60–90 °C, 1.5–6 h and 4–7, respectively. The study has focused on the structural changes as well as textural characteristics of the clay. Three activated clay samples were prepared under different treatment conditions. The samples were characterized using X-ray powder diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscope (SEM), chemical analysis and N2 adsorption techniques. Characterization of the treated clay minerals exhibited significant structural changes to a greater extent of acid-activation, from being partially crystalline to being amorphous silica. The surface area and total pore volume of clay increased proportionally with the level of acid treatment. The average pore diameter behaved differently. During the strong acid treatment, a large increase in pore volume and the enlargement of the pore size distribution were observed. This suggests that considerable structural changes and partial destruction may have occurred in this condition. The removal of methylene blue, used as cationic dye, from aqueous solution by the batch adsorption technique on three prepared acid-activated clay samples was studied. The Langmuir model was found to agree well with the experimental data.

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“…65 The amount of organic content of the clay also influences its water retention capacity as a result of the affinity of organic matter for water. 66 The effect of PAL, P-PAL on the TFN membrane structure The cross-sectional as well as surface FESEM images of PA/PSF, PA/PSF-PAL and PA/PSF-P-PAL TFN membranes are presented in Fig. 7.…”

Section: Wileyonlinelibrarycom/jctbmentioning

confidence: 99%

Facile purification of palygorskite and its effect on the performance of reverse osmosis thin film nanocomposite membrane

Mamah

Goh

Ismail

et al. 2021

J of Chemical Tech & Biotech

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BACKGROUND: Palygorskite (PAL) is a naturally occurring nanoclay characterized by a distinctive tubular structure and fibrous morphology, exhibiting chemical and thermal stability as well as large specific surface area. The tubular structure of PAL promotes the selective transportation of water molecules, hence can serve as an interesting candidate for liquid separation. In this work, a membrane substrate was fabricated using the purified PAL to enhance the flux of the thin film composite reverse osmosis. Purification of PAL enhances its interaction with polymer chain to further promote nanofiller dispersion and improves the hydrophilic properties. The water flux as well as salt rejection of the developed membranes was examined using a dead end filtration system. The membrane performance with respect to pure water flux and salt rejection was evaluated using reverse osmosis water and 2000 ppm sodium chloride solution at 15 bar operation pressure. RESULTS:The physico-chemical characterization evidenced the role of purified PAL (P-PAL) in increasing the number of pores and promoting the formation of finger like structure in the substrate layer. The water flux of thin film nanocomposite (TFN) containing P-PAL exhibited 114.6% and 43.1% improvement compared to that of neat and TFN membrane incorporated with pristine PAL respectively without compromising the salt rejection performance.CONCLUSIONS: This study highlights the purification of palygorskite and its effects on membrane water permeability in the field of water desalination.

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Effect of acid activation of palygorskite on their toluene adsorption behaviors

Cited by 89 publications

References 44 publications

Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water

Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water

Effect of Structure and Chemical Activation on the Adsorption Properties of Green Clay Minerals for the Removal of Cationic Dye

Facile purification of palygorskite and its effect on the performance of reverse osmosis thin film nanocomposite membrane

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