Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (3): 834.doi: 10.7503/cjcu20200467

• Physical Chemistry • Previous Articles     Next Articles

Construction of Active Sites in Porous Organic Polymers for Various Heavy Metal Ions Capture

ZHAO Kaiqing1, WU Ruoyu1, LUO Yifeng1, SHI Chunhong2, HU Jun1()   

  1. 1.Key Laboratory for Advanced Materials,Feringa Nobel Prize Scientist Joint Research Center,School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China
    2.Shanghai Songjiang Institute for Food and Drug Control,Shanghai 200003,China
  • Received:2020-07-17 Online:2021-03-10 Published:2021-03-08
  • Contact: HU Jun E-mail:junhu@ecust.edu.cn
  • Supported by:
    ? Supported by the National Natural Science Foundation of China(21676080)

Abstract:

Heavy metal pollution is directly related to human health and life safety, and the development of broad-spectrum and high-efficiency heavy metal adsorbents is expected to solve the problem of coexistence of multiple heavy metal pollutants in industrial wastewater. A triptycene-based porous organic polymer(TPOP) with high specific surface area was produced by crosslinking three-dimensional rigid triptycene monomer through the simple Friedel-Crafts alkylation reaction. Then, a broad-spectrum heavy metal ions adsorption active site(TPOP-CH2EDTA) was constructed in TPOP by grafting of ethylenediamine and sodium chloroacetate. The obtained TPOP-CH2EDTA showed a micro/mesoporous structure, with the main micropore size of 1.6 nm and the BET surface area of 634 m2/g, which facilitates the transfer and coordination of heavy metal ions. TPOP-CH2EDTA has a broad-spectrum adsorption for heavy metal ions, like Ag(Ⅰ), Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Co(Ⅱ), Sn(Ⅳ), Pb(Ⅱ), Cd(Ⅱ), Fe(Ⅲ), Cr(Ⅲ) are investigated, respectively, and the removal efficiency are all higher than 98%. Taking Pb(Ⅱ) as a typical heavy metal pollutant, the maximum adsorption capacity of Pb(Ⅱ) is calculated up to 184.5 mg/g by the Langmuir model. The kinetic study shows that it is a Pseudo-second-order adsorption, fast adsorption rate, and the kinetic constant k2 of 0.0173 g·mg-1·min-1. After 5 recycling use, the removal efficiency of Pb(Ⅱ) is still as high as 95.8%. More significantly, the removal efficiency of Pb(Ⅱ) and Cu(Ⅱ) in their mixture solution is either higher than 99%. For the complex real water containing large amounts of inorganic salts, like Ca(Ⅱ), Mg(Ⅱ), K(Ⅰ), Na(Ⅰ) ions, and organic compounds, the remo-val efficiency of Pb(Ⅱ) and Cu(Ⅱ) still maintains higher than 90%. Therefore, a broad-spectrum heavy metal ion adsorption active site is constructed by controlling the microstructure of porous organic polymers(such as specific surface area, pore size and adsorption site density), which provides a scheme for the coordinated removal of mixed heavy metal ions in complex water systems.

Key words: Heavy metal ion, Adsorption, Porous organic polymer, Broad spectrum, Adsorption performance

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