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>

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    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 poly­(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>

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    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
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