Sorption and removal aqueous iron(III) ion by tris(2-aminoethyl)amine moiety functionalized silica gel

ABSTRACT

The silica gel functionalized tris(2-aminoethyl)amine moiety (SG‐TAEA‐NH₂) is utilized for the sorption of iron (III) ion from water by the batch sorption process. The kinetics and thermodynamics of sorption have been carried out by controlling different parameters such as initial concentration, dosage, temperature, and pH. The sorption equilibrium is achieved during the first 20 minutes. The maximum removal of Iron(III) ion is ca. 95% upon the study conditions of C_i = 1 mg L⁻¹, T = 35 ⁰C, 80 rpm, pH = 2, and dosage = 2 g L⁻¹). Langmuir and Freundlich isotherm models are applied in order to describe the thermodynamic parameters and to understand the sorption behavior of Iron(III) ion onto SG‐TAEA‐NH₂. The SG‐TAEA‐NH₂-Fe(III) sorption follows Langmuir isotherm models (R² > 0.997). The capacity (q_max) and intensity (b) of Langmuir adsorption are calculated to be 2.553 mg.g⁻¹ and 0.7691 L.mol⁻¹, respectively. The reaction kinetic models of pseudo-first-order and pseudo-second-order, and the adsorption diffusion model of Weber-Morris intra-particle diffusion model have been used to describe the sorption rate and mechanism of the Iron(III) ion onto SG‐TAEA‐NH₂ surface. The kinetic parameters, the rate constant, and sorption capacities have been calculated. The possible sorption mechanism of iron(III) ion onto the SG‐TAEA‐NH₂ surface is proposed. The silica gel functionalized tris(2-aminoethyl)amine moiety may consider as an efficient filter to desalt low concentration of iron (III) ion.

KEYWORDS:

• SG‐TAEA‐NH₂
• iron ion
• silica g el
• adsorption
• kinetic
• pseudo-second order

Disclosure statement

No potential conflict of interest was reported by the authors.