Sorption Enhancement of Lead Ions from Water by Surface Charged Polystyrene-Supported Nano-Zirconium Oxide Composites

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• 作者：Qingrui Zhang ; Qing Du ; Ming Hua ; Tifeng Jiao ; Faming Gao ; Bingcai Pan
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：June 18, 2013
• 年：2013
• 卷：47
• 期：12
• 页码：6536-6544
• 全文大小：496K
• 年卷期：v.47,no.12(June 18, 2013)
• ISSN：1520-5851

文摘

A novel hybrid nanomaterial was fabricated by encapsulating ZrO₂ nanoparticles into spherical polystyrene beads (MPS) covalently bound with charged sulfonate groups (鈭扴O₃^{鈥?/sup>). The resultant adsorbent, Zr鈥揗PS, exhibited more preferential sorption toward Pb(II) than the simple equivalent mixture of MPS and ZrO₂. Such observation might be ascribed to the presence of sulfonate groups of the polymeric host, which could enhance nano-ZrO₂ dispersion and Pb(II) diffusion kinetics. To further elucidate the role of surface functional groups, we encapsulated nano-ZrO₂ onto another two macroporous polystyrene with different surface groups (i.e., 鈭扤(CH₃)₃+/鈥揅H₂Cl, respectively) and a conventional activated carbon. The three obtained nanocomposites were denoted as Zr鈥揗PN, Zr鈥揗PC, and Zr鈥揋AC. The presence of 鈭扴O₃鈥?/sup> and 鈭扤(CH₃)₃+ was more favorable for nano-ZrO₂ dispersion than the neutral 鈭扖H₂Cl, resulting in the sequence of sorption capacities as Zr鈥揗PS > Zr鈥揗PN > Zr鈥揋AC > Zr鈥揗PC. Column Pb(II) sorption by the four nanocomposites further demonstrated the excellent Pb(II) retention by Zr鈥揗PS. Comparatively, Zr鈥揗PN of well-dispersed nano-ZrO₂ and high sorption capacities showed much faster breakthrough for Pb(II) sequestration than Zr鈥揗PS, because the electrostatic repulsion of surface quaternary ammonium group of MPN and Pb(II) ion would result in a poor sorption kinetics. This study suggests that charged groups in the host resins improve the dispersion of embedded nanoparticles and enhance the reactivity and capacity for sorption of metal ions. Suitably charged functional groups in the hosts are crucial in the fabrication of efficient nanocomposites for the decontamination of water from toxic metals and other charged pollutants.}