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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. 11, No. 1, 2014, pp. 69-76
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Bioline Code: st14008
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. 11, No. 1, 2014, pp. 69-76
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Oxytetracycline sorption onto Iraqi montmorillonite
Barbooti, M. M.; Su, H.; Punamiya, P. & Sarkar, D.
Abstract
This paper assesses the use of certified Iraqi
montmorillonite clay as a potential sorbent for the removal
of oxytetracycline (OTC) from aqueous solutions. The clay
is characterized by a cation exchange capacity of
0.756 meq g-1 and a zero point charge at pH 8.7. Aqueous
solutions of OTC were equilibrated with montmorillonite
under various experimental conditions, such as OTC concentration,
pH and clay content, for 24 h at fixed ionic
strength. Two forms of montmorillonite were evaluated:
regular and iron-modified form. The effect of pH was
minor on OTC adsorption. Kinetic study revealed that the
sorption follows a pseudo-second-order model. Sorption
isotherm showed a good fit with the Freundlich model.
OTC sorption onto Fe-saturated montmorillonite was analyzed
statistically using a response surface design to study
the effects of experimental conditions. The introduction of
iron improved the adsorption characteristics of the clay due
to the ability of ferric ions to make stable complexes with
OTC. The most favorable operating conditions for the
treatment were deemed as follows: clay content,
6.85 g L-1, oxytetracycline concentration, 1.0 mmol L-1
and pH, 5.5 for the iron-modified form.
Keywords
Oxytetracycline; Adsorption; Montmorillonite; Iron saturation; Treatment optimization
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