Phosphate removal from aqueous solution using iron oxides: adsorption, desorption and regeneration characteristics
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Date
2018
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Colloid and Interface Science
Abstract
Dynamics of phosphate (PO4
3-) adsorption, desorption and regeneration characteristics of
three lab-synthesized iron oxides, ferrihydrite (F), goethite (G), and magnetite (M) were
evaluated in this study. Batch experiments were conducted to evaluate the impact of
several adsorption parameters including adsorbent dosage, reaction time, temperature,
pH, and ionic strength. The results showed that PO4
3- adsorption increased with reaction
time and temperature while it decreased with an increase in solution pH. Adsorption
isotherm data exhibited good agreement with the Freundlich and Langmuir model with
maximum monolayer adsorption capacities of 66.6 mg·g-1 (F), 57.8 mg·g-1 (M), and 50.5
mg·g-1 (G). h u u Δ < ΔH > ΔS >
demonstrating that PO4
3- adsorption onto tested minerals is endothermic, spontaneous,
and disordered. The PO4
3- removal mostly occurred via electrostatic attraction between
the sorbate and sorbent surfaces. Moreover, the PO4
3- sorption was reversible and could
be desorbed at varying rates in both neutral and alkaline environments. The good
desorption capacity has practical benefits for potential regeneration and re-use of the
saturated particles in wastewater treatment systems.
Description
Keywords
Phosphate, Iron oxides particles, Wastewater treatment, Regeneration
Citation
Z. Ajmal, A. Muhmood, M. Usman, S. Kizito, J. Lu, R. Dong, S. Wu, Phosphate removal from aqueous solution using iron oxides: adsorption, desorption and regeneration characteristics, Journal of Colloid and Interface Science (2018), doi: https://doi.org/10.1016/j.jcis.2018.05.084