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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 13, No. 7, 2016, pp. 1625-1640
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Bioline Code: st16153
Full paper language: English
Document type: Research Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 13, No. 7, 2016, pp. 1625-1640
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Adsorptive removal of azo dyes from aqueous solutions by natural bentonite under static and dynamic flow conditions
Berez, A.; Schäfer, G.; Ayari, F. & Trabelsi-Ayadi, M.
Abstract
This work reports new findings on the
physisorption of Foron Blue 291 on natural bentonite under
both static and dynamic flow conditions of the aqueous
solution that may prove important when using the
adsorption technique for wastewater treatment. The quantity
of dye retained by the solid matrix under both ideal
exchange conditions between dyes and adsorbents given in
a batch reactor and a pulse injection of dissolved azo dye in
a soil column composed of a mixture of mean grain-sized
sand and bentonite at different flow rates and at various
mass fractions of bentonite was studied. Column experiments
involving the use of a non-reactive tracer (Fluorescein)
were performed to examine hydrodynamic
behaviours of the clay/sand mixture studied. It is shown
that advective–dispersive transport across a clay/sand
mixture may be characterized by a double porosity medium.
The results obtained on the reactive transport of Foron
Blue 291 underscore that Foron Blue 291 adsorption
depends heavily on the mass fraction of clay in a clay/sand
mixture. With a clay mass fraction of 30 %, 77 % of the
dissolved Foron Blue 291 mass was irreversibly removed
by the adsorbent. At low flow rates, removal ratios
obtained from the dynamic reactive system were similar to
those obtained through previous static reactor experiments.
Keywords
Sorption; Irreversibility; Bentonite; Azo dye; Batch; Column experiments; Wastewater treatment
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