Polypyrrole coated secondary fly ash–iron composites: Novel floatable magnetic adsorbents for the removal of chromium (VI) from wastewater
Polypyrrole coated secondary fly ash–iron composites: Novel floatable magnetic adsorbents for the removal of chromium (VI) from wastewater
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DOI：
10.1016/j.matdes.2015.12.095
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发表时间：
2016-02
影响因子：
8.4
通讯作者：
Qi Zhou;Chunjie Yan;Wenjun Luo
中科院分区：
文献类型：
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作者：
Qi Zhou;Chunjie Yan;Wenjun Luo
传统的吸附颗粒由于沉入水底，造成二次污染，在环境水中很难回收利用。为了克服这一问题，本文制备了一种基于聚吡咯涂层的酸溶飞灰疏水磁性吸附剂(MSFA/PPy)，它可以漂浮在水体表面，吸附后容易被磁场收集。用X射线衍射仪、扫描电子显微镜、傅立叶变换红外光谱对所制备的复合材料进行了表征。制备后的水接触角明显增大，证实了疏水表面的成功获得。MSFA/PPy对铬(VI)的吸附实验表明，在pH=2.0~4.0时，吸附效果最好。铬(VI)的吸附符合准二级动力学和朗缪尔等温吸附模型。在实验条件下，MSFA/PPy对六价铬的理论最大吸附容量为66.93~119.33 mg/g。热力学分析表明，铬(VI)在MSFA/PPy上的吸附是自发过程。在再生实验中，连续三个循环的吸附数据都有一个可以接受的下降水平。研究表明，疏水性MSFA/PPy在开阔水环境下去除六价铬方面具有很大的应用潜力。
The traditional adsorbent particles always suffer from the disadvantage that they are difficult to be recovered by using in environmental water because they would sink to the water bottom, subsequently causing second contamination. To overcome the issue, a hydrophobic magnetic adsorbent based on polypyrrole coating on acid-dissolved fly ash (MSFA/PPy) was fabricated in this paper, which can float on the waterbody surface and easily collected by a magnetic field after adsorption. The prepared composite was well characterized by X-ray diffraction (XRD) patterns, Scanning electron microscope (SEM), Fourier-transform infrared (FT-IR) spectra. A significant increase on water contact angle after the preparation confirmed that the hydrophobic surface had been successfully obtained. The adsorption experiments for removal of Cr(VI) by MSFA/PPy shown that maximum adsorption occurred at pH 2.0–4.0. Cr(VI) adsorption followed pseudo-second-order kinetic and the Langmuir isotherm model. Theoretical maximum adsorption capacity of MSFA/PPy for Cr(VI) was 66.93–119.33 mg/g at experimental conditions. Thermodynamic analysis revealed that Cr(VI) adsorption onto MSFA/PPy was a spontaneous process. In regeneration experiment, there was an acceptable level of decrease in the adsorption data for three consecutive cycles. The study suggests that the hydrophobic MSFA/PPy has a great potential application in Cr(VI) removal under open water environment.