High efficient removal of chromium(VI) using glycine doped polypyrrole adsorbent from aqueous solution
High efficient removal of chromium(VI) using glycine doped polypyrrole adsorbent from aqueous solution
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DOI：
10.1016/j.cej.2012.05.110
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发表时间：
2012-08-01
影响因子：
15.1
通讯作者：
Mishra, Shivani B.
中科院分区：
文献类型：
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作者：
Ballav, Niladri;Maity, Arjun;Mishra, Shivani B.
在甘氨酸（gly）存在下，通过吡咯（Py）单体的原位聚合制备了甘氨酸掺杂聚吡咯（PPy-gly）吸附剂，用于Cr（VI）的吸附。ATR-FTIR和XRD分别证实了PPy均聚物的形成和gly在PPy基体中的包合。场发射扫描电子显微镜成像的PPy-gly揭示了近球形团聚颗粒的形成。Cr（VI）在PPy-gly吸附剂上的吸附具有高度的pH依赖性，并且与PPy均聚物相比，PPy-gly的去除效率高得多。动力学过程遵循准二级速率模型，在30-150 min内达到平衡。为了更好地理解动力学机制，还应用了颗粒内扩散模型。等温线数据符合Langmuir等温模型，在25-45 ℃时最大吸附量为217.39- 232.55mg/g。脱附实验表明，PPy-gly可再生并重复使用3次，且去除率无明显下降。Cr（VI）的吸附过程受甘氨酸和HCrO 4-离子的质子化胺基之间的离子相互作用控制。(C)出版社：Elsevier B. V.
Glycine doped polypyrrole (PPy-gly) adsorbent was prepared via in situ polymerization of pyrrole (Py) monomer in the presence of glycine (gly) for the removal of Cr(VI). Formation of PPy homopolymer and inclusion of gly in the PPy matrix were confirmed by ATR-FTIR and XRD, respectively. Field emission scanning electron microscopic imaging of PPy-gly revealed the formation of nearly spherical agglomerated particles. The adsorption of Cr(VI) onto the PPy-gly adsorbent was highly pH dependent and removal efficiency by PPy-gly was much higher compared to PPy homopolymer. The kinetic process followed pseudo-second-order rate model with equilibrium reached within 30-150 min. Intra-particle diffusion model was also applied for better understanding of kinetic mechanism. Isotherm data fitted well with the Langmuir isotherm model with maximum adsorption capacity of 217.39-232.55 mg/g at 25-45 degrees C. Desorption experiment showed PPy-gly can be regenerated and reused for three consecutive cycles without loss of its removal efficiency. The adsorption process for the removal of Cr(VI) was governed by the ionic interaction between protonated amine groups of gly and HCrO4- ions. (C) 2012 Published by Elsevier B.V.