3 research outputs found
Magnetic Porous Polymers Prepared via High Internal Phase Emulsions for Efficient Removal of Pb<sup>2+</sup> and Cd<sup>2+</sup>
Magnetic
porous polymers (MPPs) were successfully fabricated by
a facile strategy of the high internal phase emulsions (HIPEs) technique.
The microstructure, chemical composition, and magnetic properties
of the MPPs were characterized. Impregnated with polyÂ(styrene-divinylbenzene),
stabilized by the amine-functionalized Fe<sub>3</sub>O<sub>4</sub> nanoparticles (Fe<sub>3</sub>O<sub>4</sub>–NH<sub>2</sub>), the as-prepared MPPs with rich pore hierarchy were employed to
removal Pb<sup>2+</sup> and Cd<sup>2+</sup> from aqueous solution.
The MPPs display outstanding removal capacities toward Pb<sup>2+</sup> (257 mg/g) and Cd<sup>2+</sup> (129 mg/g) within 15 min, and the
encapsulated Fe<sub>3</sub>O<sub>4</sub>–NH<sub>2</sub> nanoparticles
endow the MPPs with the ability of magnetic separation (30.15 emu/g).
Additionally, the results indicate that the adsorptions of Pb<sup>2+</sup> and Cd<sup>2+</sup> are strongly dependent on pH and ionic
strength, demonstrating that the interactions of Pb<sup>2+</sup> and
Cd<sup>2+</sup> were mainly dominated by outer-sphere surface complexation
and electrostatic attraction. The adsorption process is revealed by
thermodynamic parameters to be spontaneous and endothermic. Further
study demonstrates that the adsorption is involved in ion-exchange
and cation−π interactions (between heavy metals and aromatic
ring) on the surface of MPPs. Thus, feasible preparation of the MPPs
with high adsorption capacities, excellent regeneration, and easy
separation properties opens a new expectation in the potential application
for engineering
Biochar Derived from Sawdust Embedded with Molybdenum Disulfide for Highly Selective Removal of Pb<sup>2+</sup>
Surface
interactions between the adsorbents and heavy metal ions
play an important role in the adsorption process, and appropriately
decorating the material’s surface can significantly improve
the removal capacity of the adsorbents. So, the objective of this
study is to modify biochar by coating with molybdenum disulfide (MoS<sub>2</sub>) for enhancing the adsorption of Pb<sup>2+</sup>. The biochar
pyrolyzed at 600 °C was chosen as the base to combine the flowerlike
MoS<sub>2</sub> (MoS<sub>2</sub>@biochar) by solvothermal reaction,
in which the abundant S-containing functional groups may promote the
elimination of Pb<sup>2+</sup>. The prepared MoS<sub>2</sub>@biochar
exhibits excellent adsorption capacity (189 mg/g) to Pb<sup>2+</sup> in water solution. The adsorption of Pb<sup>2+</sup> maintains a
high level under the circumstance of coexisting ions (Mg<sup>2+</sup>, Ca<sup>2+</sup>, Co<sup>2+</sup>, and Cd<sup>2+</sup>), suggesting
the high selectivity for Pb<sup>2+</sup>. The adsorption mechanism
of Pb<sup>2+</sup> on MoS<sub>2</sub>@biochar is mainly ascribed to
the inner-sphere surface complexation, in particular, metal–sulfur
chemical complexation. The easily recycled MoS<sub>2</sub>@biochar
still has high adsorption capacity for Pb<sup>2+</sup>. This work
demonstrates that the MoS<sub>2</sub>@biochar is an excellent candidate
of adsorbent for Pb<sup>2+</sup> removal