TY - JOUR
T1 - Phosphate removal from aqueous solution using iron oxides
T2 - Adsorption, desorption and regeneration characteristics
AU - Ajmal, Zeeshan
AU - Muhmood, Atif
AU - Usman, Muhammad
AU - Kizito, Simon
AU - Lu, Jiaxin
AU - Dong, Renjie
AU - Wu, Shubiao
N1 - Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2018/10/15
Y1 - 2018/10/15
N2 - 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). A thermodynamics evaluation produced ΔG < 0, ΔH > 0, and ΔS > 0, 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.
AB - 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). A thermodynamics evaluation produced ΔG < 0, ΔH > 0, and ΔS > 0, 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.
KW - Iron oxides particles
KW - Phosphate
KW - Regeneration
KW - Wastewater treatment
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U2 - 10.1016/j.jcis.2018.05.084
DO - 10.1016/j.jcis.2018.05.084
M3 - Article
C2 - 29843062
AN - SCOPUS:85047637286
SN - 0021-9797
VL - 528
SP - 145
EP - 155
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -