1 research outputs found
Aminoethanethiol-Grafted Porous Organic Polymer for Hg<sup>2+</sup> Removal in Aqueous Solution
A highly porous organic polymer,
CBAP-1, was synthesized from terephthaloyl
chloride and 1,3,5-triphenylbenzene via the Friedel–Crafts
reaction, and functionalized with either ethylenediamine (EDA) or
2-aminoethanethiol (AET) for Hg<sup>2+</sup> removal from water. Both
materials were characterized by X-ray diffraction, N<sub>2</sub> adsorption–desorption
isotherms, Fourier transform infrared spectroscopy, X-ray photoelectron
spectroscopy, inductively coupled plasma and elemental analysis, and
the stability of the porous polymers under different pH and temperature
conditions was examined. The adsorption experiments were carried out
by varying contact time, Hg<sup>2+</sup> concentration, and system
pH to study the adsorption equilibrium and kinetics. The Hg<sup>2+</sup> ion-adsorption capacities of CBAP-1Â(EDA) and CBAP-1Â(AET) were 181
and 232 mg/g, respectively, at room temperature and pH 5, and the
observed adsorption isotherms could be fitted well to the Langmuir
model (correlation factor <i>R</i><sup>2</sup> > 0.99).
Under the optimum set of conditions, the adsorption equilibrium for
CBAP-1Â(AET) was reached within a contact time of 10 min; CBAP-1Â(AET)
exhibited an excellent distribution coefficient of greater than 2.41
Ă— 10<sup>7</sup> mL/g. The adsorption kinetics could be satisfactorily
described by a pseudo-second-order model. Hg<sup>2+</sup> recovery
in the presence of commonly coexisting metal ions such as Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Pb<sup>2+</sup>, and Fe<sup>3+</sup> was also investigated. CBAP-1Â(AET) showed high Hg<sup>2+</sup> selectivity
against other ions except Pb<sup>2+</sup>. CBAP-1Â(AET) was superior
to CBAP-1Â(EDA) in terms of overall performance; it could efficiently
remove >96% of Hg<sup>2+</sup> ions in 2 min from a 100 ppm of
Hg<sup>2+</sup> solution. The material could be reused for 10 consecutive
runs with negligible loss in adsorption capacity