Mercury reduction and chemisorption on the surface of synthetic zeolite silver nanocomposites : equilibrium studies and mechanisms

Tauanov, Z. and Lee, J. and Inglezakis, V. J. (2020) Mercury reduction and chemisorption on the surface of synthetic zeolite silver nanocomposites : equilibrium studies and mechanisms. Journal of Molecular Liquids, 305. 112825. ISSN 0167-7322 (https://doi.org/10.1016/j.molliq.2020.112825)

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Abstract

This work presents the utilization of a coal power plants waste, namely coal fly ash for the synthesis of zeolites and zeolite silver nanocomposites for the removal of Hg2+ from water. Equilibrium data are derived for all materials for mercury concentration range of 10–500 mg/L and models are applied. The removal mechanisms are discussed in detail and complemented by XRD, XRF, SEM-EDS, and TEM characterizations and water phase mercury speciation modeling. According to findings, the adsorption capacity of zeolites is about 4 mg/g and increased by almost 5 times after the modification with silver nanoparticles to 20.5–22.3 mg/g. Langmuir equilibrium model fits well the experimental data of the nanocomposites indicating monolayer adsorption process. The mechanism is complex, involving Hg2+ reduction to Hg+ and possibly Hg0 followed by formation of calomel and amalgams on the surface of the nanocomposites. The mercury reduction is accompanied by Ag0 oxidation to Ag+ and subsequent formation of silver chloride.

ORCID iDs

Tauanov, Z., Lee, J. and Inglezakis, V. J. ORCID logoORCID: https://orcid.org/0000-0002-0195-0417;
  • Item type:Article
    ID code:73463
    Dates:
    Date
    Event
    1 May 2020
    Published
    2 March 2020
    Published Online
    1 March 2020
    Accepted
    Keywords:adsorption isotherms, mercury removal, nanocomposites, silver, zeolites, Chemical engineering, Electronic, Optical and Magnetic Materials, Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Spectroscopy, Physical and Theoretical Chemistry, Materials Chemistry
    Subjects:Technology > Chemical engineering
    Department:Faculty of Engineering > Chemical and Process Engineering
    Depositing user: Pure Administrator
    Date deposited:05 Aug 2020 10:38
    Last modified:23 Nov 2023 04:46
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/73463
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