Kinetic study of time-dependent fixation of UVI on biochar

Biochar, a by-product from the production of biofuel and syngas by gasification, was tested as a material for adsorption and fixation of UVI from aqueous solutions. A batch experiment was conducted to study the factors that influence the adsorption and time-dependent fixation on biochar at 20oC, inc...

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Main Authors: Ashry, Ahmed, Bailey, Elizabeth H., Chenery, Simon, Young, Scott D.
Format: Article
Published: Elsevier 2016
Subjects:
Online Access:https://eprints.nottingham.ac.uk/35815/
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author Ashry, Ahmed
Bailey, Elizabeth H.
Chenery, Simon
Young, Scott D.
author_facet Ashry, Ahmed
Bailey, Elizabeth H.
Chenery, Simon
Young, Scott D.
author_sort Ashry, Ahmed
building Nottingham Research Data Repository
collection Online Access
description Biochar, a by-product from the production of biofuel and syngas by gasification, was tested as a material for adsorption and fixation of UVI from aqueous solutions. A batch experiment was conducted to study the factors that influence the adsorption and time-dependent fixation on biochar at 20oC, including pH, initial concentration of UVI and contact time. Uranium (UVI) adsorption was highly dependent on pH but adsorption on biochar was high over a wide range of pH values, from 4.5 to 9.0, and adsorption strength was time-dependent over several days. The experimental data for pH > 7 were most effectively modelled using a Freundlich adsorption isotherm coupled to a reversible first order kinetic equation to describe the time-dependent fixation of UVI within the biochar structure. Desorption experiments showed that UVI was only sparingly desorbable from the biochar with time and isotopic dilution with 233UVI confirmed the low, or time-dependent, lability of adsorbed 238UVI. Below pH 7 the adsorption isotherm trend suggested precipitation, rather than true adsorption, may occur. However, across all pH values (4.5–9) measured saturation indices suggested precipitation was possible: autunite below pH 6.5 and either swartzite, liebigite or bayleyite above pH 6.5.
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spelling nottingham-358152020-05-04T18:25:43Z https://eprints.nottingham.ac.uk/35815/ Kinetic study of time-dependent fixation of UVI on biochar Ashry, Ahmed Bailey, Elizabeth H. Chenery, Simon Young, Scott D. Biochar, a by-product from the production of biofuel and syngas by gasification, was tested as a material for adsorption and fixation of UVI from aqueous solutions. A batch experiment was conducted to study the factors that influence the adsorption and time-dependent fixation on biochar at 20oC, including pH, initial concentration of UVI and contact time. Uranium (UVI) adsorption was highly dependent on pH but adsorption on biochar was high over a wide range of pH values, from 4.5 to 9.0, and adsorption strength was time-dependent over several days. The experimental data for pH > 7 were most effectively modelled using a Freundlich adsorption isotherm coupled to a reversible first order kinetic equation to describe the time-dependent fixation of UVI within the biochar structure. Desorption experiments showed that UVI was only sparingly desorbable from the biochar with time and isotopic dilution with 233UVI confirmed the low, or time-dependent, lability of adsorbed 238UVI. Below pH 7 the adsorption isotherm trend suggested precipitation, rather than true adsorption, may occur. However, across all pH values (4.5–9) measured saturation indices suggested precipitation was possible: autunite below pH 6.5 and either swartzite, liebigite or bayleyite above pH 6.5. Elsevier 2016-12-15 Article PeerReviewed Ashry, Ahmed, Bailey, Elizabeth H., Chenery, Simon and Young, Scott D. (2016) Kinetic study of time-dependent fixation of UVI on biochar. Journal of Hazardous Materials, 320 . pp. 55-66. ISSN 0304-3894 Biochar uranium adsorption pH isotherm kinetics http://www.sciencedirect.com/science/article/pii/S0304389416307051 doi:10.1016/j.jhazmat.2016.08.002 doi:10.1016/j.jhazmat.2016.08.002
spellingShingle Biochar
uranium
adsorption
pH
isotherm
kinetics
Ashry, Ahmed
Bailey, Elizabeth H.
Chenery, Simon
Young, Scott D.
Kinetic study of time-dependent fixation of UVI on biochar
title Kinetic study of time-dependent fixation of UVI on biochar
title_full Kinetic study of time-dependent fixation of UVI on biochar
title_fullStr Kinetic study of time-dependent fixation of UVI on biochar
title_full_unstemmed Kinetic study of time-dependent fixation of UVI on biochar
title_short Kinetic study of time-dependent fixation of UVI on biochar
title_sort kinetic study of time-dependent fixation of uvi on biochar
topic Biochar
uranium
adsorption
pH
isotherm
kinetics
url https://eprints.nottingham.ac.uk/35815/
https://eprints.nottingham.ac.uk/35815/
https://eprints.nottingham.ac.uk/35815/