Effectively removing antimony Sb(V) and Sb(III) from aqueous solutions by granular ferric hydroxide compared with manganese zeolite and activated carbon
Journal
Desalination and Water Treatment
Journal Volume
321
Start Page
100964
ISSN
1944-3986
Date Issued
2025-01
Author(s)
Abstract
Commercial granular ferric hydroxide (Fe-hydroxide), manganese zeolite (Mn-zeolite), and (powder and granular) activated carbon (PAC, Norit-GAC, and Calgon-GAC) were used for exploring the removal efficiency of antimony from aqueous solutions. Fe-hydroxide exhibited the highest adsorption capacity towards Sb(III) and Sb(V). The removal efficiency followed a decreasing order: Fe-hydroxide (99.6–99.7 %) > Mn-zeolite (35.6 %–37.0 %) > Norit-GAC (8.7 %–21.6 %) > Calgon-GAC (14.5 %–16.0 %) > PAC (4.0 %–4.9 %) for removing Sb(III) as well as Fe-hydroxide (86.7 %–95.3 %) > Calgon-GAC (18.4–25.2 %) > Norit-GAC (12.7 %–16.8 %) > PAC (6.3 %–7.5 %) > Mn-zeolite (5.9%–7.4 %) for removing Sb(V). Antimony adsorption processes by Fe-hydroxide were then conducted under different conditions (pH, material dosage, contact time, co-existing foreign ion and anion, and initial antimony concentration C o ). Some kinetic models (pseudo-1 st -order, pseudo-2 nd -order, pseudo- n th -order, and Avrami) and isotherm models (Langmuir and Freundlich) were applied for modeling data of time-dependent and equilibrium adsorption at pH eq 7.0, respectively. Sb(III) and Sb(V) exist as Sb(OH) 3 ion and Sb(OH) 6 – anions at pH 7.0. Its maximum adsorption capacity (based on the Langmuir model; Q max ) for Sb(OH) 3 ions and Sb(OH) 6 – anions reached 31,375 and 26,279 μg/g. Fe-hydroxide exhibited a stronger adsorption affinity and higher adsorption capacity of Sb(OH) 3 ions than Sb(OH) 6 – anions in water. Possible adsorption mechanism was surface complexation for Sb(OH) 3 and electrostatic attraction for Sb(OH) 6 – . Hydrogen bonding might play an integral role in adsorbing antimony onto Fe-hydroxide. Granular Fe-hydroxide can be considered a promising adsorbent for adsorbing antimony ions. • Fe-hydroxide exhibited excellent antimony adsorption capacity than manganese zeolite and activated carbon • Sb(III) ions was more favorably adsorbed by Fe-hydroxide than Sb(V) anions • Maximum adsorption capacity of Fe-hydroxide was ∼32 mg/g for Sb(III) and ∼26 mg/g for Sb(V) • Phosphate anions strongly compete with Sb(III) and Sb(V) for adsorption sites in Fe-hydroxide
Publisher
Elsevier BV
Type
journal article