高等学校化学学报

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在多孔有机聚合物中构筑广谱性重金属离子吸附活性位

赵开庆1, 吴若雨1, 罗翌峰1, 石春红2, 胡军1()   

  1. 1.华东理工大学化学与分子工程学院, 费林加诺贝尔奖科学家联合研究中心先进材料重点实验室, 上海 200237
    2.上海市松江食品药品检验所, 上海 200003
  • 收稿日期:2020-07-17
  • 通讯作者: 胡军 E-mail:junhu@ecust.edu.cn
  • 基金资助:
    国家自然科学基金(批准号(21676080);21878076)资助

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
  • Contact: HU Jun E-mail:junhu@ecust.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(21676080)

摘要:

以三维刚性结构的三蝶烯为单体, 通过简单的Friedel-Crafts烷基化反应制备得到高比表面积的三蝶烯基多孔有机聚合物(TPOP), 在TPOP中接枝乙二胺和氯乙酸钠, 构建了广谱重金属离子吸附剂(TPOP-CH2EDTA). 获得的TPOP-CH2EDTA具有微孔/介孔结构, 其微孔尺寸为1.6 nm, BET比表面积为634 m2/g, 利于重金属离子传递和配位作用的强化. TPOP-CH2EDTA对重金属离子具有吸附广谱性, 其对Ag(Ⅰ), Cu(Ⅱ), Ni(Ⅱ), Zn(Ⅱ), Co(Ⅱ), Sn(Ⅳ), Pb(Ⅱ), Cd(Ⅱ), Fe(Ⅲ)和Cr(Ⅲ)等10种重金属离子的去除率均高于98%. 以Pb(Ⅱ)为典型的重金属污染物, 通过Langmuir模型计算得到Pb(Ⅱ)的最大吸附容量高达184.5 mg/g; 具有拟二级吸附动力学特征, 吸附速率快, 动力学常数k2为0.0173 g·mg?1·min?1; 经过5次循环使用后, Pb(Ⅱ)的去除效率仍高达95.8%. TPOP-CH2EDTA对混合溶液中Pb(Ⅱ)和Cu(Ⅱ)的去除率均高于99%, 且对含有大量无机盐[如Ca(Ⅱ), Mg(Ⅱ), K(Ⅰ)和Na(Ⅰ)离子]和有机化合物的复杂真实水体系, Pb(Ⅱ)和Cu(Ⅱ)的去除效率仍高于90%. 因此, 通过调控多孔有机聚合物微观结构(如比表面积、 孔径和吸附位点密度)而构筑的广谱性重金属吸附材料, 为协同去除复杂水系统中混合重金属离子提供了方案.

关键词: 重金属离子, 吸附, 多孔有机聚合物, 广谱性, 吸附性能

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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