Improvement of the mechanical strength of alumina preforms by coating with montmorillonite/LDH gels

Mishra, Mridusmita; Bora, Jayanta; Goswamee, Rajib Lochan

doi:10.1016/j.clay.2011.04.004

Cited by 8 publications

(1 citation statement)

References 17 publications

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“…This shift could be ascribed to the intercalation the protonated amine in sodium montmorillonite. The XRD pattern of the unmodified clay sample clearly shows reflections corresponding to (001) peak , at d = 14.92 Å which is characteristic of montmorillonite. After modification with trioctylamine the interlayer spacing increases from 14.92 Å to 20.21 Å.…”

Section: Resultsmentioning

confidence: 99%

A Meticulous Study on the Adsorption of Mercury as Tetrachloromercurate(II) Anion with Trioctylamine Modified Sodium Montmorillonite and Its Application to a Coal Fly Ash Sample

Kumar

Kalidhasan

Rajesh

et al. 2012

Ind. Eng. Chem. Res.

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Clay materials have hogged the limelight for their effectiveness in environmental remediation. In this paper, we report an effective solid phase extraction method for mercury based on the adsorption of tetrachloromercurate(II) anion with trioctylamine intercalated onto sodium montmorillonite. The adsorption is facile in acidic medium, and the adsorbent was well characterized by diverse physicochemical and spectroscopic techniques. Various isotherm models were employed to correlate the experimental adsorption data. The electrostatic interaction between HgCl4 2‑ and the protonated amine is well supported by a Langmuir isotherm model with a maximum adsorption capacity of 140.84 mg g–1. The ordered transition state that arises due to the proximity of the HgCl4 2‑ and the positively charged amine is accompanied by a decrease in the translational entropy of the system. The N2 adsorption–desorption isotherm study revealed the mesoporous nature of the adsorbent, and the thermodynamically favorable adsorption process resonates well with the ensuing negative free energy and enthalpy changes in accordance with the sorption mechanism. Packed bed column study demonstrated the scale up to 800 mL sample volume at 10 mg L–1 Hg(II) concentration, and the adsorbent could be regenerated and reused for 10 cycles with thiourea as the eluent. The removal of mercury from a coal fly ash sample validated the method.

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Section: Resultsmentioning

confidence: 99%